Neurons outside CNS
Neurons in the CNS
Region of Spinal Cord containing Myelinated axons
Neurons with 3 or more processes
major neuron of cns
Some Motor Neurons
Neurons with 2 or more processes
Sensory Neurons- special senses
Primary sensory neurons in Dorsal root ganglia of spinal cord, sensory ganglia of cranial nerves
how many pairs
what do they enter/ how?
what happens after
enter intervertebral foramina then split to dorsal and ventral roots
bundles of nerve fibers that you'd see in a slide of nervous tissue
thin layer of CT around Fasicle
Much thicker fibrous sheath that encloses fasicle and perineurium
brain's outermost surrounding ct
middle tissue layer of CT on brain. Fine sheet across grooves
innermost layer directly on brain, closely adheres to the brain's surface
space between arachnoid and pia matter filled with cebrospinal fluid
|Four main regions of brain||
4 chambers of brain lined with ependymal cells that make cebrospinal fluid.
thin membrane that separates the lateral ventricles
diencephalon- longitudinal slit below choroid plexus
between brain stem and cerebellum, connects with central canal of spinal cord inferiorly. and with the 3rd ventricle through the cerebral aqueduct from the midbrain
has hemisphers seperated by longitudinal fissure, connected by corpus callosum
cortical gray matter- total brain integration and intellectual and emotional processing
basal cell nuclei (ganglia)- subcortical motor center that initiates skeletal muscle movements
cerebrum- elevated ridges of tissue, wrinkles give more SA helping with brain efficiency
cerebrum- grooves which separate Gyri divide hemispheres into lobes
cerebrum- thin transverse band of white fibers myelinated axons that carry info between two hemispheres
cerebrum- two enlargements that project from the anteroventral portion of the cerebrum, they lie over the cribriform plate of the ethmoid bone
cerebrum- cranial nerve 1- neurons lying in olfactory epithelium of upper nasal cavity that receive smell stimuli.
cerebrum- two that extend at an angle caudally and laterally from each bulb
cerebrum- bundle of white axon fibers at base of brain, posterior to septum pellucidum used for communication between the two hippocampi, the thalamus, and the mamillary bodies
cerebrum- section posterior fornix composed of small, round bundle of fibers connected from the fornix for olfactory decussation.
functions from 2 things
thalamus, hypothalamus, epithalamus
Thalamic Nuclei- sensory impulses to cerebral cortex
impulses to and from cerebral motor complex.
hypothalamus- chief integration center of ANS.
what does it contain 3
Dorsal most part of diencephalon
choroid plexus, third ventricle, pineal gland.
produces spinal fluid, secretes melanin which helps sleep/wake cycle and mood.
Diencephalon- Epithalamus- its ependymal cells produce CSF
Diencephalon- epithalamus- longitudinal slit immediately below choroid plexus.
Diencephalon- epithalamus- at posterior end of epithalamus
endocrine gland that secretes melanin
helps sleep/ wake mood
ventral surface of diencephalon, lies above pituitary gland. The pituitary gland is attached to the Infundibulum
homeostatic regulation of internal environment.
contains optic nerve, optic chiasma, mamillary body
Diencephalon- Hypothalamus- Cranial Nerve 2- retina to brain,
prominent, anterior border of hypothalamus. The rest of the hypothalamus lies posterior to optic chiasma
Diencephalon- Hypothalamus- Caudal End of hypothalamus
olfactory relay station
- most mass of diencephalon
- right and left lobes connected by intermediate mass
its the brains relay station of ascending sensory information
contains intermediate mass, nuclui, optic tract, lateral geniculate body, and medial geniculate body
Diencephalon- Thalamus- connects right and left thalamus lobes
Diencephalon- Thalamus- leads from optic chiasma to lateral geniculate body.
|lateral geniculate body||
Diencephalon- Thalamus- enlargement of thalamus
find it by tracing optic tract beneath the cerebral hemisphere
its a white ridgelike structure on lateral side of thalamus
visual relay station
|Medial Geniculate Body||
Small enlargement posterior and inferior to lateral geniculate body.
auditory relay center
structures within it
functions from what 3 structures?
Brain Stem contains
midbrain, pons, medulla oblongata
midbrain- conduction between higher and lower brain centers. visual and auditory reflex centers
medulla oblongata- decussation site of pyramidal tracts.
Controls many ANS things
dorsal surface can be seen by separating cerebral hemispheres and cerebellum
- roof has 4 prominent swellings
visual and auditory reflex centers are here.
contains corpora quadrigemia, superior and inferior colliculi, trochlear nerve, cerebral aqueduct, cerebral peduncle, and oculomotor nerve
Brain Stem- Midbrain
4 prominent swellings on roof of midbrain
1st/2nd swelling- Superior Colliculi, larger anterior swelings
3rd/4th inferior colliculi, smaller inferior
contains trochlear nerve
Brain Stem- midbrain-
2 larger anterior superior swellings on midbrain roof.
coordinate head/eye movements
Brain Stem- midbrain
3rd/4th smaller posterior swellings on midbrain roof.
auditory relay stations
Brain Stem- midbrain- cranial nerve 4
slightly posterior to inferior colliculi
mixed nerve with one extrinsic eye muscle
Brain Stem- midbrain
ventrolateral surface of midbrain
posterior to mamillary body of hypothalamus
contains corticospinal tracts descending to spinal cord
contains oculomotor nerves
Brain Stem- midbrain- cranial nerve 3
from surface of cerebral peduncle
mixed nerve for 4 of 6 extrinsic eye muscles
-iris for pupil constriction
Brain stem- midbrain
The cerebral aqueduct is a narrow opening in the brain that connects the third ventricle with the fourth ventricle, allowing cerebrospinal fluid to flow between these two areas.
superior to medulla oblongata, inferior to midbrain, ventral to cerebellum.
contains 2 fiber tracts, transverse and trapezoid body
involuntary breathing regulation
Brain Stem- Pons-
connect the two hemispheres of the cerebellum via cerebral peduncles
Brain Stem- Pons- Cranial nerve 5
extends across base of middle cerebral peduncle
will be cut short in lab, but will still have wide diameter
its a mixed nerve, afferent Head & Face.
brain stem- pons-
narrower fibers that run posterior to transverse fibers
run longitudinally forming ascending/ descending tracts.
also contain abducens nerve
brain stem- pons
cranial nerve 6-
mixed nerve 1 eye muscle
arises from trapezoid body slightly lateral to midventral line.
brain stem- medulla oblongata
lower half of brainstem
contains fourth ventricle w/ medullary velum, ventral median fissure, pyramid, olive
contains cardiac, respiratory, vomiting, and vasomotor centers. its deals with ANS functions like breathing, heart rate, and blood pressure
also it contains cranial nerves 7-12
all ascending/ descending pathways pass through medulla
brain stem- medulla-
extends from cerebral aqueduct to the obex, filled with CSF
It has a diamond shape
brain stem- medulla
- forms anterior 4th ventricle roof
|Ventral Median Fissure||
brain stem- medulla
brain stem- medulla
longitudinal tissue bands on sides of ventral median fissure. comprised of corticospinal tracts (pyramidal system)-
efferent motor signals- motor cortex to gray matter
Brain Stem- medulla
oval swellings lateral to pyramids and posterior to trapezoid body
-Afferent, relay info from spinal cord, cerebral cortex, and brain stem to cerebellum
- has appearance of separate structure attached to bottom of brain beneath cerebral hemispheres.
- fine movement
contains hemispheres, vermis
anterior superior cerebellar peduncle
cerebellum- segmented worm like groove that separates the two cerebellar hemispheres
cerebellum- 3 prominent fiber tracts that connect cerebellum to other brain regions
middle, posterior, and anterior peduncle.
|Middle Cerebellar peduncle||
connects cerebellum to pons
|posterior cerebellar peduncle||
connects cerebellum to spinal cord/ brain stem
cerebellum - midbrain
Cerebellar white matter that has appearance of a tree
brings sensory info to and from cerebellum.
|Cranial Nerve 1||
cerebrum/ olfactory bulbs
|cranial nerve 2||
|cranial nerve 3||
4/6 extrinsic eye muscles
brain stem/ cerebral peduncle
|cranial nerve 4||
brain stem/ corpora quadrigemina
|cranial nerve 5||
pons/ transverse fibers
|cranial nerve 6||
primarily motor 1/6 eye