Neurons with 3 or more processes

most common

major neuron of cns

Mostly Interneurons

Some Motor Neurons

Neurons with 2 or more processes

Sensory Neurons- special senses

Unipolar

One process

Primary sensory neurons in Dorsal root ganglia of spinal cord, sensory ganglia of cranial nerves

spinal nerves

how many pairs

what do they enter/ how?

what happens after

spinal nerves

31 pairs

enter intervertebral foramina then split to dorsal and ventral roots

cranial nerves

pairs?

12 pairs

cerebrum

diencephalon

brain stem

cerebellum

has hemisphers seperated by longitudinal fissure, connected by corpus callosum

Processes Thought

cortical gray matter- total brain integration and intellectual and emotional processing

basal cell nuclei (ganglia)- subcortical motor center that initiates skeletal muscle movements

cerebrum- cranial nerve 1- neurons lying in olfactory epithelium of upper nasal cavity that receive smell stimuli.

Purely Sensory

Diencephalon

regions

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.

Epithalamus

what does it contain 3

Diencephalon

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- at posterior end of epithalamus

endocrine gland that secretes melanin

helps sleep/ wake mood

Diencephalon-

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,

purely sensory

Diencephalon- hypothalamus-

prominent, anterior border of hypothalamus. The rest of the hypothalamus lies posterior to optic chiasma

Diencephalon- Hypothalamus- Caudal End of hypothalamus

olfactory relay station

Diencephalon-

- 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- 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

Diencephalon- Thalamus

Small enlargement posterior and inferior to lateral geniculate body.

auditory relay center

Brain Stem

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

pons-respiratory control

medulla oblongata- decussation site of pyramidal tracts.

Controls many ANS things

Midbrain

aka?

contains?

Brain Stem-

aka mescephalon

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

Trochlear Nerve

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.

Pons

Contains

brainstem

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

brain stem- medulla

midventral groove

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

arbor vitae

anterior superior cerebellar peduncle

middle peduncle

posterior peduncle

cerebellum- 3 prominent fiber tracts that connect cerebellum to other brain regions

middle, posterior, and anterior peduncle.

cerebellum

connects cerebellum to pons

cerebellum

connects cerebellum to spinal cord/ brain stem

anterior peduncle

cerebellum

cerebellum - midbrain

cerebellum

Cerebellar white matter that has appearance of a tree

brings sensory info to and from cerebellum.

olfactory

sensory

smell

cerebrum/ olfactory bulbs

optic

sensory nerve

vision

diencephalon/ hypothalamus

oculomotor

mixed

4/6 extrinsic eye muscles

mostly motor

brain stem/ cerebral peduncle

Trochlear

mixed

1/6 eye

brain stem/ corpora quadrigemina

trigeminal

mixed

head/face/ proprioceptive

pons/ transverse fibers

abducens

mixed

primarily motor 1/6 eye

pons/ trapezoid