McKinley & O’Loughlin Text Reading Assignments: Chapters 5, 10, 11, 12, 13, 21, 24 and maybe 22
Cardiovascular System: Blood
1. Describe the structural characteristics of the 3 types of muscle. Which is voluntary?
S or SN? V or IV?
Fibers are long, tapering strands that
Walls of the digestive tract,
blood vessels, respiratory,
urinary, and reproductive
Branching fibers with a centrally
positioned nucleus and connecting
Elongated, multinucleated fibers
grouped into parallel bundles
Attached to the skeleton
2. What function does the sarcoplasmic reticulum serve in muscle?
SR stores calcium ions
3. What is the basic functional unit of skeletal muscle? What is a motor unit?
A sarcomere is the functional, contractile unit of a muscle fiber
A motor unit is a motor neuron plus the skeletal muscle fibers it innervates
4. How does an increase in intracellular calcium cause a muscle fiber to contract?
calcium in terminal cisternae of sarcoplasmic reticulum binds to troponin
tropomyosin moves away from actin
Myosin-actin bridge detaches actin
5. Relative to cardiac muscle, does skeletal muscle fatigue easily?
Cardiac muscle has less calcium but more mitochondria
Skeletal muscle has no autorhythmicity
6. What can cause hypertrophy and atrophy of skeletal muscles?
Atrophy: reduced stimulus can lead to a decrease in muscle mass and tone
Damage to the nervous system or injury
Hypertrophy: exercise and repeated stimulus can lead to an increase in fiber size
Not the same as hyperplasia (increase in fiber number)
7. List 4 characteristics that differentiate red fibers from white fibers?
Slow type I oxidative – endurance
Fast type IIb glycolytic – intensity
8. Define: ligament, tendon, muscle origin, muscle insertion.
9. Draw a cross section of a skeletal muscle and show the following: epimysium, perimysium, endomysium,
fascicles, muscle fibers, myofibrils.
10. Show the relationship between the sarcomere, thin filament, thick filament, actin, myosin, Z-lines.
11. With regard to muscle contraction, what is a graded response?
Due to the varying number of motor units involved in the contractions