GUIDE STUDY And QUESTIONS - KEYES
CHAPTER 9 MUSCLES AND MUSCLE TISSUE
1. Compare and contrast the basic types of muscle tissue.
2. List four important functions of muscle tissue.
3. Describe the gross structure of a skeletal muscle.
4. Describe the microscopic structure and functional roles of the myofibrils, sarcoplasmic reticulum, and
T tubules of muscle fibers (cells).
5. Explain the sliding filament mechanism.
6. Define motor unit and explain how muscle fibers are stimulated to contract.
7. Define muscle twitch and describe the events occurring during its three phases.
8. Explain how smooth, graded contractions of a skeletal muscle are produced.
9. Differentiate between isometric and isotonic contractions.
10. Describe three ways in which ATP is regenerated during skeletal muscle contraction.
11. Define oxygen debt and muscle fatigue. List possible causes of muscle fatigue.
12. Describe factors that influence the force, velocity, and duration of skeletal muscle contraction.
13. Describe three types of skeletal muscle fibers and explain the relative value of each type.
14. Compare and contrast the effects of aerobic and resistance exercise on skeletal muscles and on other
body systems.
15. Compare the gross and microscopic anatomy of smooth muscle cells to that of skeletal muscle cells.
Review Questions
Multiple Choice/Matching
(Some questions have more than one correct answer. Select the best answer
or answers from the choices given.)
1. The connective tissue covering that encloses the sarcolemma of an
individual muscle fiber is called the (a) epimysium, (b) perimysium,
(c) endomysium, (d) periosteum.
2. A fascicle is a (a) muscle, (b) bundle of muscle fibers enclosed by a
connective tissue sheath, (c) bundle of myofibrils, (d) group of
myofilaments.
3. Thick and thin myofilaments have different compositions. For each
descriptive phrase, indicate whether the filament is (a) thick or (b) thin.
____ (1)
____ (2)
contains actin
contains ATPases
____ (3) attaches to the Z disc
____ (4) contains myosin
____ (5) contains troponin
____ (6) does not lie in the I band
4. The function of the T tubules in muscle contraction is to (a) make and
store glycogen, (b) release Ca2+ into the cell interior and then pick it up
again, (c) transmit the action potential deep into the muscle cells, (d) form
proteins.
5. The sites where the motor nerve impulse is transmitted from the nerve
endings to the skeletal muscle cell membranes are the (a) neuromuscular
junctions, (b) sarcomeres, (c) myofilaments, (d) Z discs.
6. Contraction elicited by a single brief stimulus is called (a) a twitch, (b)
wave summation, (c) multiple motor unit summation, (d) fused tetanus.
7. A smooth, sustained contraction resulting from very rapid stimulation of
the muscle, in which no evidence of relaxation is seen, is called (a) a twitch,
(b) wave summation, (c) multiple motor unit summation, (d) fused tetanus.
8. Characteristics of isometric contractions include all but (a) shortening,
(b) increased muscle tension throughout the contraction phase, (c) absence
of shortening, (d) use in resistance training.
9. During muscle contraction, ATP is provided by (a) a coupled reaction of
creatine phosphate with ADP, (b) aerobic respiration of glucose, and (c)
anaerobic glycolysis.
____ (1) Which provides ATP fastest?
____ (2) Which does (do) not require that oxygen be available?
____ (3) Which provides the highest yield of ATP per glucose molecule?
____ (4) Which results in the formation of lactic acid?
____ (5) Which has carbon dioxide and water products?
____ (6) Which is most important in endurance sports?
10. The neurotransmitter released by somatic motor neurons is (a)
acetylcholine, (b) acetylcholinesterase, (c) norepinephrine.
11. The ions that enter the muscle cell during action potential generation
are (a) calcium ions, (b) chloride ions, (c) sodium ions, (d) potassium ions.
12. Myoglobin has a special function in muscle tissue. It (a) breaks down
glycogen, (b) is a contractile protein, (c) holds a reserve supply of oxygen in
the muscle.
13. Aerobic exercise results in all of the following except (a) increased
cardiovascular system efficiency, (b) more mitochondria in the muscle cells,
(c) increased size and strength of existing muscle cells, (d) increased
neuromuscular system coordination.
14. The smooth muscle type found in the walls of digestive and urinary
system organs and that exhibits gap junctions and pacemaker cells is (a)
multiunit, (b) single-unit.
Short Answer Essay Questions
15. Name and describe the four special functional characteristics of muscle
that are the basis for muscle response.
16. Distinguish between (a) direct and indirect muscle attachments and (b)
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a tendon and an aponeurosis.
17. (a) Describe the structure of a sarcomere and indicate the relationship
of the sarcomere to the myofilament. (b) Explain the sliding filament theory
of contraction using appropriately labeled diagrams of a relaxed and a
contracted sarcomere.
18. What is the importance of acetylcholinesterase in muscle cell
contraction?
19. Explain how a slight (but smooth) contraction differs from a vigorous
contraction of the same muscle; use the concepts of multiple motor unit
summation.
20. Explain what is meant by the term excitation-contraction coupling.
21. Define motor unit.
22. Describe the three distinct types of skeletal muscle fibers.
23. True or false: Most muscles contain a predominance of one skeletal
muscle fiber type. Explain the reasoning behind your choice.
24. Describe the cause(s) of muscle fatigue and define this term clearly.
25. Define oxygen debt.
26. Name four factors that influence contractile force and two that
influence velocity and duration of contraction.
27. Smooth muscle has some unique properties, such as low energy usage,
ability to maintain contraction over long periods, and the stress-relaxation
response. Tie these properties to the function of smooth muscle in the body.
Critical Thinking and Clinical Application Questions
1. Diego was seriously out of shape the day he joined his friends for a game
of touch football. While he was running pell-mell for the ball, his left calf
began to hurt. He went to the clinic the next day and was told he had a strain.
Diego insisted that this must be wrong, because his joints did not hurt.
Clearly, Diego was confusing a strain with a sprain. Explain the difference.
2. Jim Fitch decided that his physique left much to be desired, so he joined a
local health club and began to pump iron three times weekly. After three
months of training, during which he was able to lift increasingly heavier
weights, he noticed that his arm and chest muscles were substantially larger.
Explain the structural and functional basis of these changes.
3. When a suicide victim was found, the coroner was unable to remove the
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drug vial clutched in his hand. Explain the reasons for this. If the victim had
been discovered three days later, would the coroner have had the same
difficulty? Explain.
4. Muscle-relaxing drugs are administered to a patient during major surgery.
Which of the two chemicals described next would be a good skeletal muscle
relaxant and why?
Chemical A binds to and blocks ACh receptors of muscle cells
Chemical B floods the muscle cells cytoplasm with Ca2+
5. When Eric returned from jogging, he was breathing heavily, sweating
profusely, and complained that his legs ached and felt weak. His wife poured
him a sports drink and urged him to take it easy until he could catch his
breath. On the basis of what you have learned about muscle energy
metabolism, respond to the following questions.
Why is Eric breathing heavily?
What ATP harvesting pathway have his working muscles been using
that leads to such a breath-ing pattern?
What metabolic product(s) might account for his sore muscles and his
feeling of muscle weakness?
Introduction
Skeletal muscle cells have unique characteristics which allow for body movement.
Goals
To compare and contrast smooth muscle cells, cardiac muscle cells, and skeletal muscle
cells.
To review the anatomy of the skeletal muscle.
To examine the connective tissue associated with the skeletal muscle.
To review the intracellular organization of the skeletal muscle cell.
Comparison of Skeletal, Cardiac and Smooth Muscle Cells
Skeletal Muscle Cell:
Elongated Cells
Multiple Peripheral Nuclei
Visible Striations
Cardiac Muscle:
Branching Cells
1 or 2 Central Nuclei
Visible Striations
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Smooth Muscle Cell:
Spindle-Shaped Cell
Single Central Nucleus
Lack Visible Striations
Voluntary
Involuntary
Involuntary
Whole Skeletal Muscle
Skeletal muscles attach to bones via tendons.
Internal Structure of a Skeletal Muscle
Skeletal muscles are composed of connective tissue and contractile cells.
The connective tissues surrounding the entire muscle is the epimysium. Bundles of muscle
cells are called fascicles. The connective tissues surrounding the fascicles is called
perimysium.
Label this diagram:
Internal Structure of a Fascicle
Important Points About Endomysium:
Made of connective tissue.
Surrounds individual muscle cells.
Functions to electrically insulates muscle cells from one another.
Three connective tissue layers of the muscle (endomysium, perimysium, and epimysium):
Bind the muscle cells together.
Provide strength and support to the entire muscle.
Are continuous with the tendons at the ends of the muscle.
Label this diagram:
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Internal Structure of a Skeletal Muscle Cell
Label this diagram:
Muscle fibers: Alternative name for skeletal muscle cells.
Nucleus: Contains the genetic material.
Sarcolemma: Plasma membrane of the muscle cell.
Sarcoplasmic reticulum (SR): Interconnecting tubules of endoplasmic reticulum that
surround each myofibril.
Terminal cisternae: Sac-like regions of the sarcoplasmic reticulum that contain calcium ions.
T tubules: Invaginations of the sarcolemma that project deep into the cell.
Triad: A group of one T tubule lying between two adjacent terminal cisternae.
Cytosol: Intracellular fluid.
Mitochondria: Sites of ATP synthesis.
Myofibril: Contains the contractile filaments within the skeletal muscle cell.
Structure of a Myofibril
Myofibrils: Contractile units within muscle cells.
Made of myofilaments called thin filaments and thick filaments.
Thin and thick filaments are made mainly of the proteins actin and myosin.
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Arrangement of Myofilaments
Label the diagram:
A bands: Dark areas that correspond to the areas where thick filaments are present.
I bands: Light areas that contains only thin filaments.
Z line: A protein disk within the I band that anchors the thin filaments and connects adjacent
myofibrils.
H zone: Located in the middle of each A band, this lighter stripe appears corresponding to
the region between the thin filaments.
M line: Protein fibers that connect neighboring thick filaments.
Sarcomere: The region of the myofibril between two Z lines.
Review: Organizational Levels of Skeletal Muscle
"Bundle-within-a-bundle" organization of skeletal muscle:
myofilaments
myofibril
muscle cell or muscle fiber
fascicles
whole skeletal muscle
Pyramid of Subunits
Whole muscle as a pyramid of subunits:
Fascicles
Muscle cells (Muscle Fibers)
Myofibrils
Myofilaments
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Summary
The three types of muscle cells in the body are skeletal, cardiac, and smooth.
Skeletal muscle has three layers of connective tissue: epimysium, perimysium, and
endomysium.
The striations of skeletal muscle cells are due to the organized arrangement of contractile
proteins called thick and thin filaments.
A whole muscle demonstrates a bundle-within-a-bundle organization:
myofilaments myofibrils muscle cells (muscle fibers) fascicles whole muscle
Study Questions on Anatomy Review: Skeletal Muscle Tissue
1. What is the main function of skeletal muscles?
2. Of the three types of contractile cells of the body, whichh contracts most slowly.
3. Match the following types of contractile cells to their locations (viscera and blood vessel walls,
attached to bones, heart):
___________________ a. Skeletal muscle cells
___________________ b. Cardiac muscle cells
___________________ c. Smooth muscle cells
4.Match the following types of contractile cells to the characteristics of their nuclei and presence or
absence of striations:
Cardiac Muscle Cells
Smooth Muscle Cells
Skeletal Muscle Cells
___________________ a. presence of visible striations & 1 or 2 centrally-located nuclei
___________________ b. presence of visible striations & multiple peripheral nuclei
___________________ c. absence of visible striations & single, centrally-located nuclei
number of nuclei
5. What is the name of the structure that attaches skeletal muscles to bones?
6. Bundles of skeletal muscle cells are called ________________.
7. The connective tissue which immediately surrounds a muscle is called _______________ and
the connective tissue around the fascicles is called ________________.
8. What is the function of endomysium?
9. Match these terms to their description:
Triad
T tubules
Terminal cisternae
Sarcolemma
Muscle fibers
Mitochondria
Sarcoplasmic reticulum
Myofibril
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___________________ a. Sac-like regions of the sarcoplasmic reticulum that contain
calcium ions.
___________________ b. Sites of ATP synthesis.
___________________ c. Plasma membrane of the muscle cell.
___________________ d. Alternative name for skeletal muscle cells.
___________________ e. Interconnecting tubules of endoplasmic reticulum that surround
each myofibril.
___________________ f. A group of one T tubule lying between two adjacent terminal
cisternae.
___________________ g. Invaginations of the sarcolemma that projecting deep into the
cell.
___________________ h. Contains the contractile filaments within the skeletal muscle
cell.
10.What are the names for the two types of protein filaments in a myofibril?
11. What creates the skeletal muscle cell's striated appearance?
12. Match the following:
A band
I band
H zone
______________ a. Contains only thin filaments.
______________ b. Contains only thick filaments.
______________ c. Contains both thin and thick filaments.
13.Perpendicular to the myofilaments are the Z lines and the M lines. The Z lines connect the
_____________ filaments and the M lines connect the _____________ filaments.
14.The region of the myofibril between two Z lines that is the contractile unit of a muscle cell is
called a _____________ .
15.Arrange the following from smallest structure to largest structure:
Muscle cell or muscle fiber
Fascicle
Myofilaments
Whole skeletal muscle
Myofibril
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The Neuromuscular Junction
Introduction
Motorneuronsstimulatemusclecellstocontractattheneuromuscularjunction.
Goals
Toexaminethestructureofaneuromuscularjunction.
Tounderstandthesequenceofeventsoccurringattheneuromuscularjunctionfollowingastimulus.
Role of Motor Neuron
Axonsofmotorneuronsinnervateskeletalmusclecellsattheneuromuscularjunction.
Anatomy of a Neuromuscular Junction
Thefollowingpartsofaneuromuscularjunctionandskeletalmusclecellaredescribed:
Axonterminal
SynapticVesicles
SynapticCleft
MotorEndPlate
TTubule
Sarcolemma
TerminalCisternae&SarcoplasmicReticulum
Sarcomere
Labelthisdiagram:
Overview of Neuromuscular Junction Activity
The muscle cell, including the T Tubules are polarized. Stimulation of the motor end plate on a
muscle cell by acetylcholine triggers depolarization resulting in contraction of the sarcomeres.
Arrival of Action Potential at Axon Terminal
When the action potential arrives at the axon terminal voltage-regulated calcium channels open
allowing calcium ions to enter the axon terminal.
** Note that when the action potential moves down the axon, there is a reversal of charge from positive
out, negative in, to positive in, negative out. This process is called depolarization. The charge then
reverses in a process called repolarization. The action potential moves down the axon in a wavelike fashion.
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Fusion of Synaptic Vesicles
Presence of calcium ions in the axon terminal cause synaptic vesicles to fuse with the membrane.
Release of Acetylcholine
Acetylcholine is released into the synaptic cleft & calcium ions are pumped out of the axon terminal.
** During the animation note that in addition to the acetylcholine going into the synaptic cleft (blue),
calcium ions also move out of the axon terminal (red).
Acetylcholine Binds to Receptor Sites
Acetylcholine binds to receptor sites on the motor end plate, causing an influx of sodium ions and a
small efflux of potassium ions which results in a local depolarization of the motor end plate.
Breakdown of Acetylcholine
Acetylcholine diffuses away from its receptor site, the ion channel closes, and acetylcholine is then
broken down by acetylcholinesterase.
** Carefully note the following steps that occur during the IP animation:
1. Acetylcholine (light blue ball) diffuses away from the acetylcholine receptor (green) which is a
part of the chemically regulated ion channel (purple). Note that as the acetylcholine falls off the
receptor, the ion channel on the receptor closes, preventing further flow of sodium and
potassium ions.
2. The acetylcholine binds to the enzyme acetylcholinesterase (aqua-colored).
3. The acetylcholinesterase breaks down the acetylcholine into two pieces, inactivating it.
** Note that after the acetylcholine has broken down, its parts are taken back up into the axon terminal
where they can be reassembled into acetylcholine again. This is not shown on the animation.
Action Potential Propagation
An action potential is generated which propagates along the sarcolemma in all directions and down
the T Tubules.
Calcium Release from Terminal Cisternae
The action potential causes the release of calcium ions from the terminal cisternae into the cytosol.
Contraction of the Muscle Cell
Calcium ions trigger a contraction of the muscle cell.
Neuromuscular Animation
The sequence of events in the neuromuscular animation are given.
Summary
Each skeletal muscle cell is individually stimulated by a motor neuron.
The neuromuscular junction is the place where the terminal portion of a motor neuron axon meets a
muscle cell membrane, separated by a synaptic cleft.
An action potential arriving at the axon terminal brings about the release of acetylcholine, which leads
to depolarization of the motor end plate.
Depolarization of the motor end plate triggers an action potential that propagates along the
sarcolemma and down the T Tubules.
This action potential causes the release of calcium ions from the terminal cisternae into the cytosol,
triggering contraction of the muscle cell.
Study Questions on the Neuromuscular Junction:
1. What causes skeletal muscle cells to contract?
2. What is the place called where a motor neuron stimulates a muscle cell?
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3. How are skeletal muscle cells are electrically insulated from each other?
4. What is a motor neuron?
5. What part of the motor neuron carries impulses to the muscle? Describe its structure.
6. Match the following terms to their description:
Axon terminal
Synaptic Vesicles
Motor End Plate
T Tubule
Terminal Cisternae & Sarcoplasmic Reticulum
Synaptic Cleft
Sarcolemma
Sarcomere
________________________ a. Invaginations of the sarcolemma penetrating deep into the interior of
the muscle cell.
________________________ b. The space between the axon terminal and the motor end plate.
________________________ c. The swollen distal end of the motor neuron axon.
________________________ d. The muscle cell membrane.
________________________ e. Structures within the axon terminal that contain the neurotransmitter
acetylcholine.
________________________ f. The contractile unit of the muscle cell that extends from one Z line to
the next.
________________________ g. Structures within skeletal muscle cells that serve as reservoirs of
calcium ions.
________________________ h. A folded region of the sarcolemma at the neuromuscular junction.
7. What is a polarized membrane?
8. Describe the resting membrane potential with respect the neuromuscular junction?
9. Describe the T Tubules when they are at resting membrane potential.
10.List the following events in the order they occur:
_____ a. The motor end plate is depolarized.
_____ b. The sarcomeres contract.
_____ c. Acetyl choline is released from the axon terminal into the synaptic cleft.
_____ d. The depolarization triggers an action potential which propagates along the sarcolemma and
the T tubules.
_____ e. An action potential arrives at the axon terminal
11. What happens at the neuromuscular junction when the action potential arrives at the axon terminal.
12.What is the effect of the presence of calcium ions inside the axon terminal?
13. What two events happen after the synaptic vesicles fuse with the membrane of the axon terminal?
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14. What happens to acetylcholine after it is released into the synaptic cleft?
15. What happens after the acetylcholine binds to the acetylcholine receptor on the motor end plate?
16. When does the chemically regulated ion channel on the motor end plate close?
17. What happens to the acetyl choline after it diffuses away from its receptor on the motor end plate?
18. The movement of the sodium ions through the chemically regulated ion channel initiates a
depolarization of the motor end plate. What happens after this depolarization is generated?
19. What happens as the action potential moves down the T Tubules?
20. What happens when calcium ion is present in the cytosol of the muscle cell?
21. Place the following events in their proper sequence:
_____ a. Acetyl choline is released into the synaptic cleft.
_____ b. Action potential propagates along the sarcolemma and down the T Tubules.
_____ c. Synaptic vesicles fuse to membrane of axon terminal.
_____ d. Motor end plate becomes depolarized.
_____ e. Action potential is initiated on the sarcolemma.
_____ f. Action potential arrives at the axon terminal.
_____ g. Calcium ions are released from the terminal cisternae.
_____ h. Acetylcholine binds to receptor sites on the motor end plate.
_____ i. The muscle cell contracts.
_____ j. Calcium ions enter the axon terminal.
1.
What insulates each muscle cell? _________________________
2.
Synaptic vesicles in the axon terminal of a motor neuron contain what
neurotransmitter? _________________________
3.
An action potential in the axon terminal of a motor neuron opens what type
of ion channels? _________________________
4.
By what means of membrane transport does the neurotransmitter leave the
axon terminal? _________________________
5.
Binding of neurotransmitter to the receptors on the motor endplate open
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what type of ion channels? _________________________
6.
Opening of these channels leads to _______________ of the motor endplate.
7.
How is the neurotransmitter removed from the synaptic cleft?
8.
As a result of question 6, an action potential is propagated along the
_________________ of the muscle cell and down the _______________
into the cell.
9.
The result of this action potential releases what ion from the terminal
cisternae? ________
Overview of Muscle Tissues
1.
2.
3.
Describe the properties of the three types of muscle tissue.
Identify the functional characteristics of muscle tissue.
Explain the functions of muscles.
Skeletal Muscle
4.
Examine the gross anatomical features of skeletal muscle.
5.
6.
Explore the microscopic anatomy of skeletal muscle, and the specific arrangement of each
element in relation to the others.
7.
Describe the structural arrangement of the neuromuscular junction, and explain the
mechanism of generation of an action potential across the sarcolemma.
8.
Explain the sliding filament mechanism of muscle fiber contraction.
9.
Define a motor unit, and explain the events of a muscle twitch.
12.
Describe the mechanisms through which muscles are supplied with ATP.
Smooth Muscle
15.
Indicate the microscopic anatomy of smooth muscle cells, and compare to skeletal muscle
17.
Describe the types of smooth muscle and their locations in the body.
cells.
CH 11 - NERVOUS TISSUE
1. List the basic functions of the nervous system.
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2. Explain the structural and functional divisions of the nervous system.
3. List the types of neuroglia and cite their functions.
4. Define neuron, describe its important structural components, and relate each to a functional role.
5. Differentiate between a nerve and a tract, and between a nucleus and a ganglion.
6. Explain the importance of the myelin sheath and describe how it is formed in the central and
peripheral nervous systems.
7. Classify neurons structurally and functionally.
8. Define resting membrane potential and describe its electrochemical basis.
9. Compare and contrast graded and action potentials.
10. Explain how action potentials are generated and propagated along neurons.
11. Define absolute and relative refractory periods.
12. Define saltatory conduction and contrast it to conduction along unmyelinated fibers.
13. Define synapse. Distinguish between electrical and chemical synapses structurally and in their
mechanisms of information transmission.
14. Distinguish between excitatory and inhibitory postsynaptic potentials.
15. Describe how synaptic events are integrated and modified.
16. Define neurotransmitter and name several classes of neurotransmitters.
17. Describe common patterns of neuronal organization and processing.
Multiple Choice/Matching
(Some questions have more than one correct answer. Select the best answer or
answers from the choices given.)
1. Which of the following structures is not part of the central nervous system?
(a) the brain, (b) a nerve, (c) the spinal cord, (d) a tract.
2. Match the names of the supporting cells found in column B with the appropriate
descriptions in column A.
Column A
Column B
___(1) myelinates nerve fibers in the CNS
(a) astrocyte
___(2) lines brain cavities
(b) ependymal cell
___(3) myelinates nerve fibers in the PNS
(c) microglia
___(4) CNS phagocytes
(d) oligodendrocyte
___(5) helps regulate the ionic composition (e) satellite cell
of CNS extracellular fluid
(f) Schwann cell
3. What type of current flows through the axolemma during the steep phase of
repolarization? (a) chiefly a sodium current, (b) chiefly a potassium current, (c)
sodium and potassium currents of approximately the same magnitude.
5.
The velocity of nerve impulse conduction is greatest in (a) heavily myelinated,
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large-diameter fibers, (b) myelinated, small-diameter fibers, (c) unmyelinated, smalldiameter fibers, (d) unmyelinated, large-diameter fibers.
6. Chemical synapses are characterized by all of the following except (a) the
release of neurotransmitter by the presynaptic membranes, (b) postsynaptic
membranes bearing receptors that bind neurotransmitter, (c) ions flowing through
protein channels from the presynaptic to the postsynaptic neuron, (d) a fluid-filled
gap separating the neurons.
7. Biogenic amine neurotransmitters include all but (a) norepinephrine, (b)
acetylcholine, (c) dopamine, (d) serotonin.
8. The neuropeptides that act as natural opiates are (a) substance P, (b)
somatostatin, (c) cholecystokinin, (d) enkephalins.
10. The anatomical region of a multipolar neuron that has the lowest threshold for
generating an AP is the (a) soma, (b) dendrites, (c) axon hillock, (d) distal axon.
11. An IPSP is inhibitory because (a) it hyperpolarizes the postsynaptic
membrane, (b) it reduces the amount of neurotransmitter released by the
presynaptic terminal, (c) it prevents calcium ion entry into the presynaptic terminal,
(d) it changes the threshold of the neuron.
12. Identify the neuronal circuits described by choosing the correct response from
the key.
Key: (a) converging
(b) diverging
(c) parallel after-discharge
(d) reverberating
___(1) Impulses continue around and around the circuit until one neuron
stops firing.
___(2) One or a few inputs ultimately influence large numbers of neurons.
___(3) Many neurons influence a few neurons.
___(4) May be involved in exacting types of mental activity.
Short Answer Essay Questions
13. Explain both the anatomical and functional divisions of the nervous system.
Include the subdivisions of each.
14. (a) Describe the composition and function of the cell body. (b) How are axons
and dendrites alike? In what ways (structurally and functionally) do they differ?
15. (a) What is myelin? (b) How does the myelination process differ in the CNS
and PNS?
16. (a) Contrast unipolar, bipolar, and multipolar neurons structurally. (b) Indicate
where each is most likely to be found.
17. What is the polarized membrane state? How is it maintained? (Note the
relative roles of both passive and active mechanisms.)
18. Describe the events that must occur to generate an AP. Relate the sequence
of changes in permeability to changes in the ion channels, and explain why the AP
is an all-or-none phenomenon.
19. Since all APs generated by a given nerve fiber have the same magnitude,
how does the CNS know whether a stimulus is strong or weak?
20. (a) Explain the difference between an EPSP and an IPSP. (b) What
specifically determines whether an EPSP or IPSP will be generated at the
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postsynaptic membrane?
21. Since at any moment a neuron is likely to have thousands of neurons
releasing neurotransmitters at its surface, how is neuronal activity (to fire or not to
fire) determined?
22. The effects of neurotransmitter binding are very brief. Explain.
23. During a neurobiology lecture, a professor repeatedly refers to group A and
group B fibers, absolute refractory period, and nodes of Ranvier. Define these
terms.
24. Distinguish between serial and parallel processing.
25. Briefly describe the three stages of neuron development.
26. What factors appear to guide the outgrowth of an axon and its ability to make
the correct synaptic contacts?
Critical Thinking and Clinical Application Questions
1. Mr. Miller is hospitalized for cardiac problems. Somehow, medical orders are
mixed up and Mr. Miller is infused with a K+-enhanced intravenous solution meant
for another patient who is taking potassium-wasting diuretics (i.e., drugs that cause
excessive loss of potassium from the body in urine). Mr. Millers potassium levels
are normal before the IV is administered. What do you think will happen to Mr.
Millers resting membrane potentials? To his neurons ability to generate APs?
2. Local anesthetics block voltage-gated Na+ channels. General anesthetics are
thought to activate chemically gated Cl channels, thereby rendering the nervous
system quiescent while surgery is performed. What specific process do anesthetics
impair, and how does this interfere with nerve transmission?
3. When admitted to the emergency room, John was holding his right hand, which
had a deep puncture hole in its palm. He explained that he had fallen on a nail while
exploring a barn. John was given an antitetanus shot to prevent neural
complications. Tetanus bacteria fester in deep, dark wounds, but how do they travel
in neural tissue?
4. Rochelle developed multiple sclerosis when she was 27. After eight years she
had lost a good portion of her ability to control her skeletal muscles. How did this
happen?
5. In the Netherlands a young man named Jan was admitted to the emergency
room. He and his friends had been to a rave. His friends say he started twitching
and having muscle spasms which progressed until he was stiff as a board. On
examination, staff found a marked increase in muscle tone and hyperreflexia
involving facial and limb muscles. In his pocket, he had unmarked dark yellow
tablets with dark flecks. Analysis of the tablets showed them to contain a mixture of
ecstasy and strychnine. Ecstasy would not cause this clinical picture, but strychnine,
which blocks glycine receptors, could. Explain how.
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CHAPTER 12 -THE CENTRAL NERVOUS SYSTEM
1. Describe the process of brain development.
2. Name the major regions of the adult brain.
3. Name and locate the ventricles of the brain.
4. List the major lobes, fissures, and functional areas of the cerebral cortex.
5. Explain lateralization of hemisphere function.
6. Differentiate between commissures, association fibers, and projection fibers.
7. Describe the general function of the basal nuclei (basal ganglia).
8. Describe the location of the diencephalon, and name its subdivisions.
9. Identify the three major regions of the brain stem, and note the functions of
each area.
10. Describe the structure and function of the cerebellum.
11. Locate the limbic system and the reticular formation, and explain the role of
each functional system.
14. Describe consciousness (vs. coma).
17. Describe how meninges, cerebrospinal fluid, and the blood-brain barrier protect
the CNS.
18. Describe the formation of cerebrospinal fluid, and follow its circulatory pathway.
20. Describe the embryonic development of the spinal cord.
21. Describe the gross and microscopic structure of the spinal cord.
22. List the major spinal cord tracts, and classify each as a motor or sensory tract.
Review Questions
Multiple Choice/Matching
(Some questions have more than one correct answer. Select the best answer
or answers from the choices given.)
1. The primary motor cortex, Brocas area, and the premotor area are
located in which lobe? (a) frontal, (b) parietal, (c) temporal, (d) occipital.
2. The innermost layer of the meninges, delicate and closely apposed to
the brain tissue, is the (a) dura mater, (b) corpus callosum, (c) arachnoid, (d)
pia mater.
3. Cerebrospinal fluid is formed by (a) arachnoid villi, (b) the dura mater, (c)
choroid plexuses, (d) all of these.
18
4. A patient has suffered a cerebral hemorrhage that has caused
dysfunction of the precentral gyrus of his right cerebral cortex. As a result, (a)
he cannot voluntarily move his left arm or leg, (b) he feels no sensation on
the left side of his body, (c) he feels no sensation on his right side.
5. Choose the proper term from the key to respond to the statements
describing various brain areas.
Key: (a)
(d) corpus striatum
(b) corpora quadrigemina
(e) hypothalamus
(c) corpus callosum
(f) medulla
___(1) basal nuclei involved in fine control of motor activities
___(2) region where there is a gross crossover of fibers of descending
pyramidal tracts
___(3) control of temperature, autonomic nervous system reflexes, hunger,
and water balance
___(4) houses the substantia nigra and cerebral aqueduct
___(5) relay stations for visual and auditory stimuli input; found in midbrain
___(6) houses vital centers for control of the heart, respiration, and blood
pressure
___(7) brain area through which all the sensory input is relayed to get to the
cerebral cortex
___(8) brain area most concerned with equilibrium, body posture, and
coordination of motor activity
6. Which of the following tracts convey vibration and other specific
sensations that can be precisely localized? (a) pyramidal tract, (b) medial
lemniscal tract, (c) lateral spinothalamic tract, (d) reticulospinal tract.
7. Destruction of the ventral horn cells of the spinal cord results in loss of
(a) integrating impulses, (b) sensory impulses, (c) voluntary motor impulses,
(d) all of these.
8. Fiber tracts that allow neurons within the same cerebral hemisphere to
communicate are (a) association tracts, (b) commissures, (c) projection
tracts.
9. A number of brain structures are listed below. If an area is primarily gray
matter, write a in the answer blank; if mostly white matter, respond with b.
___(1) cerebral cortex
___(2) corpus callosum
___(3) cranial nerve nuclei
___(4) spinothalamic tract
___(5) precentral gyri
Short Answer Essay Questions
12. Make a diagram showing the three primary (embryonic) brain vesicles.
Name each and then use clinical terminology to name the resulting adult
brain regions.
13. (a) What is the advantage of having a cerebrum that is highly
19
convoluted? (b) What term is used to indicate its grooves? Its outward folds?
(c) What groove divides the cerebrum into two hemispheres? (d) What
divides the parietal from the frontal lobe? The parietal from the temporal
lobe?
14. (a) Make a rough drawing of the lateral aspect of the left cerebral
hemisphere. (b) You may be thinking, But I just cant draw! So, name the
hemisphere involved with most peoples ability to draw. (c) On your drawing,
locate the following areas and provide the major function of each: primary
motor cortex, premotor cortex, somatosensory association area, primary
sensory area, visual and auditory areas, prefrontal cortex, Wernickes and
Brocas areas.
15. (a) What does lateralization of cortical functioning mean? (b) Why is the
term cerebral dominance a misnomer?
16. (a) What is the function of the basal nuclei?
17. (a) Explain how the cerebellum is physically connected to the brain
stem. (b) List ways in which the cerebellum is very similar to the cerebrum.
18. Describe the role of the cerebellum in maintaining smooth, coordinated
skeletal muscle activity.
19. (a) Where is the limbic system located? (b) What structures make up
this system? (c) How is the limbic system important in behavior?
20. (a) Localize the reticular formation in the brain. (b) What does RAS
mean, and what is its function?
21. List four ways in which the CNS is protected.
22. (a) How is cerebrospinal fluid formed and drained? Describe its
pathway within and around the brain. (b) What happens if CSF is not drained
properly? Why is this consequence more harmful in adults?
23. What constitutes the blood-brain barrier?
24. A brain surgeon is about to make an incision. Name all the tissue layers
that she cuts through from the skin to the brain.
25. (a) Define concussion and contusion. (b) Why does severe brain stem
injury result in unconsciousness?
26. Describe the spinal cord, depicting its extent, its composition of gray
and white matter, and its spinal roots.
Critical Thinking and Clinical Application Questions
1. A 10-month-old infant has an enlarging head circumference and delayed
overall development. She has a bulging anterior fontanel and her CSF
pressure is elevated. Based on these findings, answer the following questions:
(a) What are the possible cause(s) of an enlarged head? (b) What tests might
20
be helpful in obtaining information about this infants problem? (c) Assuming
the tests conducted showed the cerebral aqueduct to be constricted, which
ventricles or CSF-containing areas would you expect to be enlarged? Which
would likely not be visible? Respond to the same questions based on a finding
of obstructed arachnoid villi.
2. Mrs. Jones has had a progressive decline in her mental capabilities in the
last five or six years. At first her family attributed her occasional memory
lapses, confusion, and agitation to grief over her husbands death six years
earlier. When examined, Mrs. Jones was aware of her cognitive problems and
was shown to have an IQ score approximately 30 points less than would be
predicted by her work history. A CT scan showed diffuse cerebral atrophy.
The physician prescribed an acetylcholinesterase inhibitor and Mrs. Jones
showed slight improvement. What is Mrs. Joness problem? Why did the
acetylcholinesterase inhibitor help?
3. Robert, a brilliant computer analyst, suffered a blow to his anterior skull
from a falling rock while mountain climbing. Shortly thereafter, it was obvious
to his co-workers that his behavior had undergone a dramatic change.
Although previously a smart dresser, he was now unkempt. One morning, he
was observed defecating into the wastebasket. His supervisor ordered Robert
to report to the companys doctor immediately. What region of Roberts brain
was affected by the cranial blow?
4. Mrs. Adams is ready to deliver her first baby. Unfortunately, the baby
appears to have a myelomeningocele. Would a vaginal or surgical (C-section)
delivery be more appropriate and why?
5. The medical chart of a 68-year-old man includes the following notes:
Slight tremor of right hand at rest; stony facial expression; difficulty in
initiating movements. (a) Based on your present knowledge, what is the
diagnosis? (b) What brain areas are most likely involved in this mans
disorder, and what is the deficiency? (c) How is this condition currently
treated?
6. Cynthia, a 16-year-old girl, was rushed to the hospital after taking a bad
spill off the parallel bars. After she had a complete neurological workup, her
family was told that she would be permanently paralyzed from the waist down.
The neurologist then outlined for Cynthias parents the importance of
preventing complications in such cases. Common complications include
urinary infection, bed sores, and muscular spasms. Using your knowledge of
neuroanatomy, explain the underlying reasons for these complications.
7. Herrera Mrs. suffered a stroke two weeks ago. Initially she was unable to
move her right arm and the right side of her face, but her paralysis has
decreased markedly. However, she still has a great deal of difficulty speaking.
Mrs. Herreras speech consists of very few words. She struggles to produce
these words and they are distorted and separated by long pauses. Her
comprehension of written and spoken language is unaltered. She is fully
aware of what happened to her and is tearful much of the time. Which side of
the brain and which particular area of the brain was affected by Mrs. Herreras
stroke?
8. Five-year-old Amy wakes her parents up at 3 am crying and complaining
of a sore neck, a severe headache, and feeling sick to her stomach. She has
a temperature of 40C (104F) and hides her eyes, saying that the lights are
too bright. The emergency physician suspects meningitis and performs a
lumbar tap. Using your knowledge of neuroanatomy, explain into which space
and at what level of the vertebral column the needle will be inserted to perform
this test. Which fluid is being obtained and why?
21
CHAPTER 13 THE PERIPHERAL NERVOUS SYSTEM AND REFLEX ACTIVITY
1. Define peripheral nervous system and list its components.
2.
Classify general sensory receptors by structure, stimulus detected,
and
3.
body location.
3. Outline the events that lead to sensation and perception.
4. Describe receptor and generator potentials and sensory adaptation.
5. Describe the main aspects of sensory perception.
Define ganglion and indicate the general body location of ganglia.
6.
7. Describe the general structure of a nerve, and follow the process of nerve
regeneration.
8. Name the 12 pairs of cranial nerves; indicate the body region and structures
innervated by each.
9. Describe the formation of a spinal nerve and the general distribution of its
rami.
10. Define plexus. Name the major plexuses and describe the distribution and
function of the peripheral nerves arising from each plexus.
Compare and contrast the motor endings of somatic and autonomic nerve
11. fibers.
12. Outline the three levels of the motor hierarchy.
13. Compare the roles of the cerebellum and basal nuclei in controlling motor
activity.
14. Name the components of a reflex arc and distinguish between autonomic
and somatic reflexes.
15. Compare and contrast stretch, flexor, crossed-extensor, and Golgi tendon
reflexes.
22
Review Questions
Multiple Choice/Matching
(Some questions have more than one correct answer. Select the best
answer or answers from the choices given.)
1. The large onion-shaped receptors that are found deep in the dermis
and in subcutaneous tissue and that respond to deep pressure are (a)
Merkel discs, (b) Pacinian corpuscles, (c) free nerve endings, (d) muscle
spindles.
2. Proprioceptors include all of the following except (a) muscle spindles,
(b) Golgi tendon organs, (c) Merkel discs, (d) joint kinesthetic receptors.
3. The aspect of sensory perception by which the cerebral cortex
identifies the site or pattern of stimulation is (a) perceptual detection, (b)
feature abstraction, (c) pattern recognition, (d) spatial discrimination.
4. The neural machinery of the spinal cord is at the (a) precommand level,
(b) projection level, (c) segmental level.
5. Dorsal root ganglia contain (a) cell bodies of somatic motor neurons,
(b) axon terminals of somatic motor neurons, (c) cell bodies of autonomic
motor neurons, (d) axon terminals of sensory neurons, (e) cell bodies of
sensory neurons.
6. The connective tissue sheath that surrounds a fascicle of nerve fibers
is the (a) epineurium, (b) endoneurium, (c) perineurium, (d) neurilemma.
7. Match the receptor type from column B to the correct description in
column A.
Column A
Column B
__(1) pain, itch, and temperature receptors (a) Ruffini endings
__(2) contains intrafusal fibers and type Ia (b) Golgi tendon organ
and II sensory endings
(c) muscle spindle
__(3) discriminative touch receptor in
(d) free nerve endings
hairless skin (fingertips)
(e) Pacinian corpuscle
__(4) contains receptor endings wrapped
(f) Meissners corpuscle
around thick collagen bundles
__(5) rapidly adapting deep-pressure
receptor
__(6) slowly adapting deep-pressure
receptor
8. Match the names of the cranial nerves in column B to the appropriate
description in column A.
Column A
Column B
__(1) causes pupillary constriction
(a) abducens
__(2) is the major sensory nerve of the
(b) accessory
face
(c) facial
__(3) serves the sternocleido-mastoid and (d) glossopharyngeal
trapezius muscles
(e) hypoglossal
__(4) are purely sensory (two nerves)
(f) oculomotor
__(5) serves the tongue muscles
(g) olfactory
__(6) allows you to chew your food
(h) optic
__(7) is impaired in Bells palsy
(i) trigeminal
__(8) helps to regulate heart activity
(j) trochlear
__(9) helps you to hear and to maintain
(k) vagus
your balance
(l) vestibulocochlear
23
__, __, __,__ (10) contain parasympathetic
motor fibers (four nerves)
9. For each of the following muscles or body regions, identify the plexus
and the peripheral nerve(s) (or branch of one) involved. Use choices from
keys A and B.
__; __(1) the diaphragm
Key A: Plexuses
__; __(2) muscles of the posterior leg
(a) brachial
__; __(3) anterior thigh muscles
(b) cervical
__; __(4) medial thigh muscles
(c) lumbar
__; __(5) anterior arm muscles that flex the (d) sacral
forearm
Key B: Nerves
__; __(6) muscles that flex the wrist and
(1) common fibular
digits (two nerves)
(2) femoral
__; __(7) muscles that extend the wrist and (3) median
digits
(4) musculocutaneous
__; __(8) skin and extensor muscles of the (5) obturator
posterior arm
(6) phrenic
__; __(9) fibularis muscles, tibialis anterior,
(7) radial
and toe extensors
(8) tibial
__; __,__,__, __(10) elbow joint
(9) ulnar
10. Characterize each receptor activity described below by choosing the
appropriate letter and number(s) from keys A and B.
__, __(1) You are enjoying an ice cream
Key A:
cone.
(a) exteroceptor
__, __(2) You have just scalded yourself
(b) interoceptor
with hot coffee.
(c) proprioceptor
__, __(3) The retinas of your eyes are
Key B:
stimulated.
(1) chemoreceptor
__, __(4) You bump (lightly) into someone. (2) mechanoreceptor
__, __(5) You are in a completely dark
(3) nociceptor
room and reaching toward the light switch.
(4) photoreceptor
__, __(6) You feel uncomfortable after a
(5) thermoreceptor
large meal.
11. A reflex that causes reciprocal activation of the antagonist muscle is
the (a) crossed-extensor, (b) flexor, (c) Golgi tendon, (d) muscle stretch.
Short Answer Essay Questions
12. What is the functional relationship of the peripheral nervous system to
the central nervous system?
13. List the structural components of the peripheral nervous system, and
describe the function of each component.
14. Differentiate clearly between sensation and perception.
15. Central pattern generators (CPGs) are found at the segmental level of
motor control. (a) What is the job of the CPGs? (b) What controls them, and
where is this control localized?
16. Make a diagram of the hierarchy of motor control. Position the CPGs,
the command neurons, and the cerebellum and basal nuclei in this scheme.
17. How do the types of motor activity controlled by the direct (pyramidal)
and indirect systems differ?
18. Describe the functional problems that would be experienced by a
24
person in which these fiber tracts have been cut: (a) lateral spinothalamic,
(b) anterior and posterior spinocerebellar, (c) tectospinal.
19. Why are the cerebellum and basal nuclei called precommand areas?
20. Explain why damage to peripheral nerve fibers is often reversible,
whereas damage to CNS fibers rarely is.
21. (a) Describe the formation and composition of a spinal nerve. (b)
Name the branches of a spinal nerve (other than the rami communicantes),
and indicate their distribution.
22. (a) Define plexus. (b) Indicate the spinal roots of origin of the four
nerve plexuses, and name the general body regions served by each.
23. Differentiate between ipsilateral and contralateral reflexes.
24. What is the homeostatic value of flexor reflexes?
25. Compare and contrast flexor and crossed-extensor reflexes.
26. Explain how a crossed-extensor reflex exemplifies both serial and
parallel processing.
27. What clinical information can be gained by conducting somatic reflex
tests?
28. What is the structural and functional relationship between spinal
nerves, skeletal muscles, and dermatomes?
Critical Thinking and Clinical Application Questions
1. In 1962 a boy playing in a train yard fell under a train. His right arm was
cut off cleanly by the train wheel. Surgeons reattached the arm, sewing
nerves and vessels back together. The boy was told he should eventually
regain the use of his arm but that it would never be strong enough to pitch a
baseball. Explain why full recovery of strength was unlikely.
2. Jefferson, a football quarterback, suffered torn menisci in his right knee
joint when tackled from the side. The same injury crushed his common
fibular nerve against the head of the fibula. What locomotor problems did
Jefferson have after this?
3. As Harry fell off a ladder, he grabbed a tree branch with his right hand,
but unfortunately lost his grip and fell heavily to the ground. Days later, Harry
complained that his upper limb was numb. What was damaged in his fall?
4. Mr. Frank, a former stroke victim who had made a remarkable recovery,
suddenly began to have problems reading. He complained of seeing double
and also had problems navigating steps. He was unable to move his left eye
downward and laterally. What cranial nerve was the site of lesion? (Right or
left?)
5. One of a group of rabbit hunters was accidentally sprayed with buckshot
in both of his gluteal prominences. When his companions saw that he would
survive, they laughed and joked about where he had been shot. They were
horrified and ashamed a week later when it was announced that their friend
would be permanently paralyzed and without sensation in both legs from the
knee down, as well as on the back of his thighs. What had happened?
6. You are at a party at Marys house. After you are blindfolded, an object
(a key or a rabbits foot) is placed in your hand. What spinal tracts carry the
signals to the cortex that will allow you to differentiate between these
objects, and what aspects of sensory perception are operating?
7. Fumiko, a 19-year-old nursing student, had had a runny nose and sore
throat for several days. Upon waking, her face felt twisted. When she
examined her face in the mirror, she noticed that the right side looked
25
droopy and she was unable to move the facial muscles on that side. This
made it difficult to eat or speak clearly. Which cranial nerve was affected and
on which side? What is a common cause of this condition?
[
CHAPTER 14 THE AUTONOMIC NERVOUS SYSTEM
1. Define autonomic nervous system and explain its relationship to the peripheral nervous system.
2. Compare the somatic and autonomic nervous systems relative to effectors, efferent pathways, and
neurotransmitters released.
3. Compare and contrast the functions of the parasympathetic and sympathetic divisions.
4. For the parasympathetic and sympathetic divisions, describe the site of CNS origin, locations of
ganglia, and general fiber pathways.
5. Define cholinergic and adrenergic fibers, and list the different types of their receptors.
6. Describe the clinical importance of drugs that mimic or inhibit adrenergic or cholinergic effects.
7. State the effects of the parasympathetic and sympathetic divisions on the following organs: heart,
blood vessels, gastrointestinal tract, lungs, adrenal medulla, and external genitalia.
8. Describe autonomic nervous system controls.
Review Questions
Multiple Choice/Matching
(Some questions have more than one correct answer. Select the best answer
or answers from the choices given.)
1. All of the following characterize the ANS except (a) two-neuron efferent
chain, (b) presence of nerve cell bodies in the CNS, (c) presence of nerve
cell bodies in the ganglia, (d) innervation of skeletal muscles.
2. Relate each of the following terms or phrases to either the sympathetic
(S) or parasympathetic (P) division of the autonomic nervous system:
___ (1) short preganglionic, long postganglionic fibers
___ (2)
___ (3) craniosacral outflow
___ (4) adrenergic fibers
___ (5) cervical ganglia
___ (6) otic and ciliary ganglia
___ (7) generally short duration action
___ (8) increases heart rate and blood pressure
___ (9) increases gastric motility and secretion of lacrimal, salivary, and
digestive juices
___
(10)
innervates blood vessels
___
(11)
26
most active when you are swinging in a hammock
___
(12)
active when you are running in the Boston Marathon
3. Preganglionic neurons develop from (a) neural crest cells, (b) neural
tube cells, (c) alar plate cells, (d) endoderm.
4. The white rami communicantes contain what kind of fibers? (a)
preganglionic parasympathetic, (b) postganglionic parasympathetic, (c)
preganglionic sympathetic, (d) postganglionic sympathetic.
5. Prevertebral sympathetic ganglia are involved with the innervation of the
(a) abdominal organs, (b) thoracic organs, (c) head, (d) arrector pili, (e) all of
these.
Short Answer Essay Questions
6. Briefly explain why the following terms are sometimes used to refer to
the autonomic nervous system: involuntary nervous system and emotionalvisceral system.
7. Describe the anatomical relationship of the white and gray rami to the
spinal nerve, and indicate the kind of fibers found in each ramus type.
8. Indicate the results of sympathetic activation of the following structures:
sweat glands, eye pupils, adrenal medulla, heart, lungs, liver, blood vessels
of vigorously working skeletal muscles, blood vessels of digestive viscera,
salivary glands.
9. Which of the effects listed in response to question 8 would be reversed
by parasympathetic activity?
10. Which ANS fibers release acetylcholine? Which release
norepinephrine?
11. Describe the meaning and importance of sympathetic tone and
parasympathetic tone.
12. List the receptor subtypes for ACh and NE, and indicate the major sites
where each type is found.
13. What area of the brain is most directly involved in mediating autonomic
reflexes?
14. Describe the importance of the hypothalamus in controlling the
autonomic nervous system.
15. Describe the basis and uses of biofeedback training.
16. What manifestations of decreased autonomic nervous system efficiency
are seen in elderly individuals?
17. Ganglionic neurons were initially called postganglionic neurons. Why is
this a misnomer?
Critical Thinking and Clinical Application Questions
1. Mr. Johnson has been suffering from functional urinary retention and a
hypoactive urinary bladder. Bethanechol, a drug that mimics acetylcholines
autonomic effects, is prescribed to manage his problem. First explain the
rationale for prescribing bethanechol, and then predict which of the following
27
adverse effects Mr. Johnson might experience while taking this drug (select all
that apply): dizziness, low blood pressure, deficient tear formation, wheezing,
increased mucus production in bronchi, deficient salivation, diarrhea,
cramping, excessive sweating, undesirable erection of penis.
2. Mr. Jake was admitted to the hospital with excruciating pain in his left
shoulder and arm. He was found to have suffered a heart attack. Explain the
phenomenon of referred pain as exhibited by Mr. Jake.
3. A 32-year-old woman complains that she has been experiencing aching
pains in the medial two fingers of both hands and that during such episodes,
the fingers become blanched and then blue. Her history is taken, and it is
noted that she is a heavy smoker. The physician advises her that she must
stop smoking and states that he will not prescribe any medication until she
has discontinued smoking for a month. What is this womans problem, and
why was she told to stop smoking?
4. Tiffany, a 21-year-old college student, had been having trouble sleeping,
crying frequently, and having recurrent thoughts of suicide. She was
prescribed an antidepressant. Like many such drugs, this antidepressant has
anticholinergic side effects. What side effects might Tiffany experience in the
first week of treatment?
5. As the aroma of freshly brewed coffee drifted by dozing Henrys nose, his
mouth started to water and his stomach began to rumble. Explain his
reactions in terms of ANS activity.
6. Which clinical condition has the classic signs of blue fingertips that later
turn red?
CHAPTER 16 THE ENDOCRINE SYSTEM
1. Indicate important differences between hormonal and neural controls of body functioning.
2. List the major endocrine organs, and describe their body locations.
3. Distinguish between hormones, paracrines, and autocrines.
4. Describe how hormones are classified chemically.
5. Describe the two major mechanisms by which hormones bring about their effects on their target
tissues.
6. List three kinds of interaction of different hormones acting on the same target cell.
7. Explain how hormone release is regulated.
8. Describe structural and functional relationships between the hypothalamus and the pituitary gland.
9. List and describe the chief effects of adenohypophyseal hormones.
10. Discuss the structure of the neurohypophysis, and describe the effects of the two hormones it
releases.
11. Describe important effects of the two groups of hormones produced by the thyroid gland. Follow the
process of thyroxine formation and release.
28
12. Indicate general functions of parathyroid hormone.
13. List hormones produced by the adrenal gland, and cite their physiological effects.
14. Compare and contrast the effects of the two major pancreatic hormones.
15. Describe the functional roles of hormones of the testes and ovaries.
16. Briefly describe the importance of thymic and pineal hormones.
17. Name a hormone produced by the heart, and localize enteroendocrine cells.
18. Briefly explain the hormonal functions of the placenta, kidney, skin, and adipose tissue.
Review Questions
Multiple Choice/Matching
(Some questions have more than one correct answer. Select the best answer
or answers from the choices given.)
1. The major stimulus for release of parathyroid hormone is (a) hormonal,
(b) humoral, (c) neural.
2. The anterior pituitary secretes all but (a) antidiuretic hormone, (b) growth
hormone, (c) gonadotropins, (d) TSH.
3. A hormone not involved in glucose metabolism is (a) glucagon, (b)
cortisone, (c) aldosterone, (d) insulin.
4. Parathyroid hormone (a) increases bone formation and lowers blood
calcium levels, (b) increases calcium excretion from the body, (c) decreases
calcium absorption from the gut, (d) demineralizes bone and raises blood
calcium levels.
5. Choose from the following key to identify the hormones described.
Key: (a) aldosterone
(e) oxytocin
(b) antidiuretic hormone (f) prolactin
(c) growth hormone
(g) T
(d) luteinizing hormone (h) TSH
___ 1. important anabolic hormone; many of its effects mediated by IGFs
___ 2. involved in water balance; cause the kidneys to conserve water (two
choices)
___ 3. stimulates milk production
___ 4. tropic hormone that stimulates the gonads to secrete sex hormones
___ 5. increases uterine contractions during birth
___ 6. major metabolic hormone(s) of the body
___ 7. causes reabsorption of sodium ions by the kidneys
___ 8. tropic hormone that stimulates the thyroid gland to secrete thyroid
hormone
___ 9. secreted by the neurohypophysis (two choices)
___ 10. the only steroid hormone in the list
6. A hypodermic injection of epinephrine would (a) increase heart rate,
increase blood pressure, dilate the bronchi of the lungs, and increase
peristalsis, (b) decrease heart rate, decrease blood pressure, constrict the
bronchi, and increase peristalsis, (c) decrease heart rate, increase blood
pressure, constrict the bronchi, and decrease peristalsis, (d) increase heart
rate, increase blood pressure, dilate the bronchi, and decrease peristalsis.
29
7. Testosterone is to the male as what hormone is to the female? (a)
luteinizing hormone, (b) progesterone, (c) estrogen, (d) prolactin.
8. If anterior pituitary secretion is deficient in a growing child, the child will
(a) develop acromegaly, (b) become a dwarf but have fairly normal body
proportions, (c) mature sexually at an earlier than normal age, (d) be in
constant danger of becoming dehydrated.
9. If there is adequate carbohydrate intake, secretion of insulin results in (a)
lower blood glucose levels, (b) increased cell utilization of glucose, (c)
storage of glycogen, (d) all of these.
10. Hormones (a) are produced by exocrine glands, (b) are carried to all
parts of the body in blood, (c) remain at constant concentration in the blood,
(d) affect only non-hormone-producing organs.
11. Some hormones act by (a) increasing the synthesis of enzymes, (b)
converting an inactive enzyme into an active enzyme, (c) affecting only
specific target organs, (d) all of these.
12. Absence of thyroxine would result in (a) increased heart rate and
increased force of heart contraction, (b) depression of the CNS and lethargy,
(c) exophthalmos, (d) high metabolic rate.
13. Chromaffin cells are found in the (a) parathyroid gland, (b) anterior
pituitary gland, (c) adrenal gland, (d) pineal gland.
14. Atrial natriuretic peptide secreted by the heart has exactly the opposite
function of this hormone secreted by the zona glomerulosa: (a) antidiuretic
hormone, (b) epinephrine, (c) calcitonin, (d) aldosterone, (e) androgens.
Short Answer Essay Questions
15. Define hormone.
16. Which type of hormone receptorplasma membrane bound or
intracellularwould be expected to provide the most long-lived response to
hormone binding and why?
17. (a) Describe the body location of each of the following endocrine
organs: anterior pituitary, pineal gland, pancreas, ovaries, testes, and adrenal
glands. (b) List the hormones produced by each organ.
18. Name two endocrine glands (or regions) that are important in the stress
response, and explain why they are important.
19. The anterior pituitary is often referred to as the master endocrine organ,
but it, too, has a master. What controls the release of anterior pituitary
hormones?
20. The posterior pituitary is not really an endocrine gland. Why not? What
is it?
21. A colloidal, or endemic, goiter is not really the result of malfunction of
the thyroid gland. What does cause it?
22. List some problems that elderly people might have as a result of
decreasing hormone production.
23. Name a hormone secreted by a muscle cell and two hormones secreted
by neurons.
24. How are the hyperglycemia and lipidemia of insulin deficiency linked?
Critical Thinking and Clinical Application Questions
1.
Richard Neis had symptoms of excessive secretion of PTH (high blood
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calcium levels), and his physicians were certain he had a parathyroid gland
tumor. Yet when surgery was performed on his neck, the surgeon could not
find the parathyroid glands at all. Where should the surgeon look next to find
the tumorous parathyroid gland?
2. Mary Morgan has just been brought into the emergency room of City
General Hospital. She is perspiring profusely and is breathing rapidly and
irregularly. Her breath smells like acetone (sweet and fruity), and her blood
glucose tests out at 650 mg/100 ml of blood. She is in acidosis. What
hormone drug should be administered, and why?
3. Johnny, a 5-year-old boy, has been growing by leaps and bounds; his
height is 100% above normal for his age. He has been complaining of
headaches and vision problems. A CT scan reveals a large pituitary tumor. (a)
What hormone is being secreted in excess? (b) What condition will Johnny
exhibit if corrective measures are not taken? (c) What is the probable cause of
his headaches and visual problems?
4. Sean, a 42-year-old single father, goes to his physician complaining of
nausea and chronic fatigue. He reports having felt fatigued and listless for
about half a year, but he had attributed this to stress. He has lost considerable
weight and, strangely, his skin has a healthy tan, even though he spends long
hours at work and rarely ventures outside. His doctor finds very low blood
pressure and a rapid, weak pulse. Blood tests show that Sean does not have
anemia, but his plasma glucose, cortisol, and Na+ are low, and his plasma K+
is high. His doctor orders an ACTH stimulation test, in which Seans secretion
of cortisol is measured after he is given a synthetic form of ACTH. (a) What
would account for Seans low plasma Na+ and high plasma K+? (b) What is the
reason for doing an ACTH stimulation test? (c) What gland is primarily
affected if ACTH does not cause a normal elevation of cortisol secretion?
What is this abnormality called? (d) What gland is primarily affected if ACTH
does cause an elevation of cortisol secretion?
5. Roger Proulx has severe arthritis and has been taking prednisone (a
glucocorticoid) for two months. He isnt feeling well, complains of repeated
colds, and is extremely puffy (edematous). Explain the reason for these
symptoms.
CHAPTER 27 THE REPRODUCTIVE SYSTEM
1. Describe the common function of the male and female reproductive systems.
2. Describe the structure and function of the testes, and explain the importance of their location in the
scrotum.
3. Describe the structure of the penis, and indicate its role in the reproductive process.
4. Describe the location, structure, and function of the accessory reproductive organs of the male.
5. Discuss the sources and functions of semen.
7. Define meiosis. Compare and contrast it to mitosis.
8. Outline events of spermatogenesis.
9. Discuss hormonal regulation of testicular function and the physiological effects of testosterone on
male reproductive anatomy.
10. Describe the location, structure, and function of the ovaries.
31
11. Describe the location, structure, and function of each of the organs of the female reproductive duct
system.
13. Discuss the structure and function of the mammary glands.
14. Describe the process of oogenesis and compare it to spermatogenesis.
15. Describe ovarian cycle phases, and relate them to events of oogenesis.
16. Describe the regulation of the ovarian and uterine cycles.
17. Discuss the physiological effects of estrogens and progesterone.
Review Questions
Multiple Choice/Matching
(Some questions have more than one correct answer. Select the best answer
or answers from the choices given.)
1. The structures that draw an ovulated oocyte into the female duct system
are (a) cilia, (b) fimbriae, (c) microvilli, (d) stereocilia.
2. The usual site of embryo implantation is (a) the uterine tube, (b) the
peritoneal cavity, (c) the vagina, (d) the uterus.
3. The male homologue of the female clitoris is (a) the penis, (b) the
scrotum, (c) the penile urethra, (d) the testis.
4. Which of the following is correct relative to female anatomy? (a) The
vaginal orifice is the most dorsal of the three openings in the perineum, (b)
the urethra is between the vaginal orifice and the anus, (c) the anus is
between the vaginal orifice and the urethra, (d) the urethra is the more ventral
of the two orifices in the vulva.
5. Secondary sex characteristics are (a) present in the embryo, (b) a result
of male or female sex hormones increasing in amount at puberty, (c) the
testis in the male and the ovary in the female, (d) not subject to withdrawal
once established.
6. Which of the following produces the male sex hormones? (a) seminal
vesicles, (b) corpus luteum, (c) developing follicles of the testes, (d) interstitial
cells.
7. Which will occur as a result of nondescent of the testes? (a) Male sex
hormones will not be circulated in the body, (b) sperm will have no means of
exit from the body, (c) inadequate blood supply will retard the development of
the testes, (d) viable sperm will not be produced.
8. The normal diploid number of human chromosomes is (a) 48, (b) 47, (c)
46, (d) 23, (e) 24.
9. Relative to differences between mitosis and meiosis, choose the
statements that apply only to events of meiosis. (a) tetrads present, (b)
produces two daughter cells, (c) produces four daughter cells, (d) occurs
throughout life, (e) reduces the chromosomal number by half, (f) synapsis
and crossover of homologues occur.
10. Match the key choices with the descriptive phrases below.
Key: (a) androgen-binding protein (e) inhibin
(b) estrogens
(f) LH
(c) FSH
(g) progesterone
(d) GnRh
(h) testosterone
____(1) Hormones that directly regulate the ovarian cycle
____(2) Chemicals in males that inhibit the pituitary-testicular axis
32
____(3) Hormone that makes the cervical mucus viscous
____(4) Potentiates the activity of testosterone on spermatogenic cells
____(5) In females, exerts feedback inhibition on the hypothalamus and
anterior pituitary
____(6) Stimulates the secretion of testosterone
11. The menstrual cycle can be divided into three continuous phases.
Starting from the first day of the cycle, their consecutive order is (a)
menstrual, proliferative, secretory, (b) menstrual, secretory, proliferative, (c)
secretory, menstrual, proliferative, (d) proliferative, menstrual, secretory, (e)
secretory, proliferative, menstrual.
12. Spermatozoa are to seminiferous tubules as oocytes are to (a) fimbriae,
(b) corpus albicans, (c) ovarian follicles, (d) corpora lutea.
13. Which of the following does not add a secretion that makes a major
contribution to semen? (a) prostate, (b) bulbourethral glands, (c) testes, (d)
vas deferens.
14. The corpus luteum is formed at the site of (a) fertilization, (b) ovulation,
(c) menstruation, (d) implantation.
15. The sex of a child is determined by (a) the sex chromosome contained
in the sperm, (b) the sex chromosome contained in the oocyte, (c) the
number of sperm fertilizing the oocyte, (d) the position of the fetus in the
uterus.
16. FSH is to estrogen as estrogen is to (a) progesterone, (b) LH, (c) FSH,
(d) testosterone.
17. A drug that reminds the pituitary to produce gonadotropins might be
useful as (a) a contraceptive, (b) a diuretic, (c) a fertility drug, (d) an abortion
stimulant.
Short Answer Essay Questions
18. Why is the term urogenital system more applicable to males than to
females?
19. The spermatid is haploid, but it is not a functional gamete. Name and
describe the process during which a spermatid is converted to a motile
sperm, and describe the major structural (and functional) regions of a sperm.
20. Oogenesis in the female results in one functional gametethe egg, or
ovum. What other cells are produced? What is the significance of this rather
wasteful type of gamete productionthat is, production of a single functional
gamete instead of four, as seen in males?
21. List three secondary sex characteristics of females.
22. Describe the events and possible consequences of menopause.
23. Define menarche. What does it indicate?
24. Trace the pathway of a sperm from the male testes to the uterine tube
of a female.
25. In menstruation, the stratum functionalis is shed from the endometrium.
Explain the hormonal and physical factors responsible for this shedding.
(Hint: See Figure 27.22.)
26. Both the epithelium of the vagina and the cervical glands of the uterus
help prevent the invasion and spread of vaginal pathogens. Explain how each
of these mechanisms works.
27. Some anatomy students were saying that the bulbourethral glands of
males act like city workers who come around and clear parked cars from the
street before a parade. What did they mean by this analogy?
28. A man swam in a cold lake for an hour and then noticed that his
33
scrotum was shrunken and wrinkled. His first thought was that he had lost his
testicles. What had really happened?
Critical Thinking and Clinical Application Questions
1. Gina Marciano, a 44-year-old mother of eight children, visited her
physician complaining of a bearing down sensation in her pelvis, low
backache, and urinary incontinence. A vaginal examination showed that the
external os of her cervix was just inside the vaginal orifice and her perineum
exhibited large keloids. Her history revealed that she was a member of a
commune located in the nearby mountains that shunned hospital births (if at
all possible). What do you think Ginas problem is and what caused it? (Be
anatomically specific.)
2. Harry, a sexually active adolescent, appeared in the emergency room
complaining of a penile drip and pain in urination. An account of his recent
sexual behavior was requested and recorded. (a) What do you think Harrys
problem is? (b) What is the causative agent of this disorder? (c) How is the
condition treated, and what may happen if it isnt treated?
3. A 36-year-old mother of four is considering tubal ligation as a means of
ensuring that her family gets no larger. She asks the physician if she will
become menopausal after the surgery. (a) How would you answer her
question and explain away her concerns? (b) Explain what a tubal ligation is.
4. Mr. Scanlon, a 76-year-old gentleman, is interested in a much younger
woman. Concerned because of his age, he asks his urologist if he will be able
to father a child. What questions would a physician ask of this man, and what
diagnostic tests would be ordered?
5. Lucy had both her left ovary and her right uterine tube removed surgically
at age 17 because of a cyst and a tumor in these organs. Now, at age 32, she
remains healthy and is expecting her second child. How could Lucy conceive
a child with just one ovary and one uterine tube, widely separated on opposite
sides of the pelvis like this?
Chapter 28 Pregnancy and Human Development
3. Define fertilization.
4. Explain the process and product of cleavage.
5. Describe implantation and placenta formation, and list placental functions.
6. Describe gastrulation and its consequence.
7. Name and describe the formation, location, and function of the extraembryonic
8. Define organogenesis and indicate the important roles of the three primary germ layers in this
process.
34
9. Describe unique features of the fetal circulation.
10. Indicate the duration of the fetal period, and note the major events of fetal development.
11. Describe functional changes in maternal reproductive organs and in the cardiovascular, respiratory,
and urinary systems during pregnancy.
12. Indicate the effects of pregnancy on maternal metabolism and posture.
13. Explain how labor is initiated, and describe the three stages of labor.
14. Outline the events leading to the first breath of a newborn.
15. Describe changes that occur in the fetal circulation after birth.
16. Explain how the breasts are prepared for lactation.
Review Questions
Multiple Choice/Matching
(Some questions have more than one correct answer. Select the best answer
or answers from the choices given.)
1. Indicate whether each of the following statements is describing (a)
cleavage or (b) gastrulation.
____(1) period during which a morula forms
____(2) period when vast amounts of cell migration occur
____(3) period when the three embryonic germ layers appear
____(4) period during which the blastocyst is formed
2. Most systems are operational in the fetus by four to six months. Which
system is the exception to this generalization, affecting premature infants?
(a) the circulatory system, (b) the respiratory system, (c) the urinary system,
(d) the digestive system.
3. The zygote contains chromosomes from (a) the mother only, (b) the
father only, (c) both the mother and father, but half from each, (d) each
parent and synthesizes others.
4. The outer layer of the blastocyst, which later attaches to the uterus, is
the (a) decidua, (b) trophoblast, (c) amnion, (d) inner cell mass.
5. The fetal membrane that forms the basis of the umbilical cord is the (a)
allantois, (b) amnion, (c) chorion, (d) yolk sac.
6. In the fetus, the ductus arteriosus carries blood from (a) the pulmonary
artery to the pulmonary vein, (b) the liver to the inferior vena cava, (c) the
right ventricle to the left ventricle, (d) the pulmonary trunk to the aorta.
7. Which of the following changes occur in the babys cardiovascular
system after birth? (a) Blood clots in the umbilical vein, (b) the pulmonary
vessels dilate as the lungs expand, (c) the ductus venosus becomes
obliterated, as does the ductus arteriosus, (d) all of these.
8. Following delivery of the infant, the delivery of the afterbirth includes the
(a) placenta only, (b) placenta and decidua, (c) placenta and attached (torn)
fetal membranes, (d) chorionic villi.
9. Identical twins result from the fertilization of (a) one ovum by one sperm,
(b) one ovum by two sperm, (c) two ova by two sperm, (d) two ova by one
sperm.
10. The umbilical vein carries (a) waste products to the placenta, (b)
oxygen and food to the fetus, (c) oxygen and food to the placenta, (d) oxygen
35
and waste products to the fetus.
11. The germ layer from which the skeletal muscles, heart, and skeleton
are derived is the (a) ectoderm, (b) endoderm, (c) mesoderm.
12. Which of the following cannot pass through placental barriers? (a)
blood cells, (b) glucose, (c) amino acids, (d) gases, (e) antibodies.
13. The most important hormone in initiating and maintaining lactation after
birth is (a) estrogen, (b) FSH, (c) prolactin, (d) oxytocin.
14. The initial stage of labor, during which the neck of the uterus is
stretched, is the (a) dilation stage, (b) expulsion stage, (c) placental stage.
Short Answer Essay Questions
16. Fertilization involves much more than a mere restoration of the diploid
chromosome number. (a) What does the process of fertilization entail on the
part of both the egg and sperm? (b) What are the effects of fertilization?
17. Cleavage is an embryonic event that mainly involves mitotic divisions.
How does cleavage differ from mitosis occurring during life after birth, and
what are its important functions?
18. The life span of the ovarian corpus luteum is extended for nearly three
months after implantation, but otherwise it deteriorates. (a) Explain why this
is so. (b) Explain why it is important that the corpus luteum remain functional
following implantation.
19. The placenta is a marvelous, but temporary, organ. Starting with a
description of its formation, show how it is an intimate part of both fetal and
maternal anatomy and physiology during the gestation period.
20. Why is it that only one sperm out of the hundreds (or thousands)
available enters the oocyte?
21. What is the function of gastrulation?
22. (a) What is a breech presentation? (b) Cite two problems with this type
of presentation.
23. What factors are believed to bring about uterine contractions at the
termination of pregnancy?
24. Explain how the flat embryonic disc takes on the cylindrical shape of a
tadpole.
Critical Thinking and Clinical Application Questions
1. Jennie, a freshman in your dormitory, tells you she just discovered that
she is three months pregnant. She recently bragged that since she came to
college she has been drinking alcohol heavily and experimenting with every
kind of recreational drug she could find. From the following, select the advice
you would give her, and explain why it is the best choice. (a) She must stop
taking drugs, but they could not have affected her fetus during these first few
months of her pregnancy. (b) Harmful substances usually cannot pass from
mother to embryo, so she can keep using drugs. (c) There could be defects in
the fetus, so she should stop using drugs and visit a doctor as soon as
possible. (d) If she has not taken any drugs in the last week, she is okay.
2. During Mrs. Joness labor, the obstetrician decided that it was necessary
to perform an episiotomy. What is an episiotomy, and why is it done?
36
3. A woman in substantial pain called her doctor and explained (between
sobs) that she was about to have her baby right here. The doctor calmed her
and asked how she had come to that conclusion. She said that her water had
broken and that her husband could see the babys head. (a) Was she right? If
so, what stage of labor was she in? (b) Do you think that she had time to
make it to the hospital 60 miles away? Why or why not?
4. Mary is a heavy smoker and has ignored a friends advice to stop
smoking during her pregnancy. On the basis of what you know about the
effect of smoking on physiology, describe how Marys smoking might affect
her fetus.
5. While Mortimer was cramming for his anatomy test, he read that some
parts of the mesoderm become segmented. He suddenly realized that he
could not remember what segmentation is. Define segmentation, and give two
examples of segmented structures in the embryo.
6. Assume a sperm has penetrated a polar body and their nuclei fuse. Why
would it be unlikely for the resulting cell to develop into a healthy embryo?
37