CH. 2.2 + 2.3 Neuroanatomy 1

Summarize the sequence of events in the development of the fetal nervous system.  Understand neuroanatomical planes and directional terms.  Name the major divisions of the brainstem and midbrain, and identify key functions performed by each.

Early neural development stages

1. Ectoderm a outer layer of embryo tissue thickens and creates a neural plate
   the neural plate folds inward (concaves) creating a neural groove

2. the neural groove ends folds into a cannoli, and fuse together within following weeks

3. at 4th week its completely fused and created the neural tube 

4. the neural tube will eventually go on to form the spinal cord

Ectoderm

starts flat, folds in and becomes the neural tube

Neural Tube and what it develops into (brain FMH
and spinal cord parts)

develops into the spinal cord and the brain (CNS)

the tube divides into 3 parts of the brain

(first the forebrain - front,

midbrain - middle,

hindbrain- back)

the rest forms the spinal cord

first 3 parts then spilt into 5 (tho mid brain doesnt technichally spilt)

Forebrain

(prosencephalon)

what does it divide into?

front part of neural tube

will splits into

the telecephalon or cerebral hemispheres

diecephalon - thalamus, hypothalamus

Midbrain
(menescephalon)

what does it divide into?

stays as the midbrain no spilting

Hindbrain

(rhocephalon)

what does it divide into?

develops into

metecephalon - cerebellum and pons

myelecephalon - medulla

why does kink in neural tube stays in humans

because we are bipedal, and we keep kink in the neural tube, while 4 legged animals get that kink straightened out

which part of the brain evolved the earliest?

the hindbrain because the back of the brain is responsible for the most basic functions we need to survive

Anatomical Conventions (what are different cuts, planes)

useful for seeing parts of brain

Horizontial plane

saggital plane

Coronal cut

Horizontial plane

cuts brain horizontally, view from above

saggital plane

cuts brain vertically in half

Coronal cut

cuts brain into a front and back. tiara cut

Anterior

General front

Posterior

General back

Rostral

front of brain (upper on diagnol)

Caudal

back of the brain (lower on diagnol)

Medial

Middle (in between side to side)

Lateral

side to side (ex. from right to left hemisphere)

Brain is symetrical (mostly)

if you cut the brain in hald you’ll find the two hemispheres, and most structures are paired or mirrored, some exceptions,

hesmispheres connected by corpis callosum

Contralateral control

each side of brain controls and takes in information from the opposite side of the body.
(ex move right hand, left side of brain is being used)
damage on right hemisphere you’ll have prblems controling the left side

ipsilateral control

same side control

Brain stem (function and parts)

controls breathing heart rate, swallowing
used to relay info from spinal cord to the brain and to spinal cord

midbrain

pons

medulla

Pons (funciton and parts)

connects the crebellum and the brain

controls sensroy and motor processing

nuclei of the cranial nerves (bunc=dle of grey matter in CNS)

(remember there are 12 and in pairs, few highlights

CN 5 - chewing facial senation

abducens - eye movement

facial - facial sensations

vestibulocochlear - hearing and balance

Medulla (funciton and parts)

responsible for basic vital functions, dmage here is thus fatal since it controls breathing, heart rate, blood pressure regulation

sensory, motor processing

contains nuclei of cranial nerves 9-12

glossopharyngeal

vagus - main nerve of ANS, main control of medulla

accessory

hypoglossal

Midbrain (funciton and parts)

Tectum

Tegmentum

Tectum (midbrain)

roof/back processes sensory info,

has bumps called

superiors and interior collcululi (pair)

superior (rostrral bumps)

res ponsible for sound and visual processing.

inferior (caudal bumps)

sound processing

superiorcollcululi

from tectum of midbrain
res ponsible for sound and visual processing.

interior collcululi

from tectum of midbrain

sound processing

Tegmentum - midbrain (know cranial nerves)

motor control, nuclei of cranial nerves, moves eye

cranial nerves 3 and 4 moves eye

oculomotor: opening eye

trochlea: eye movement

red nucleus - motor control

substantial nigra - dopamine, reward, motor control

Penaqueductal gray - pain perception

reticular motion - sleep and arousal, motor control, temp regulation

oculomotor:

from tegmentum of midbrain
cranial nerve that
opening eye

Trochlea

from tegmentum of midbrain
cranial nerve that moves eye

Red nucleus

from tegmentum of midbrain
motor control

Substanstil nigra

from tegmentum of midbrain
dopamin reward center, motor control

Penaqueductal gray

from tegmentum of midbrain
pain perception

Recticular motor 
(sounds like testicular like waking up wiith wood)

from tegmentum of midbrain
sleep, arousal, motor control , temp regulation