A&P: Nervous System - Brain and Cranial Nerves Flashcards
How Many Cranial Nerves?
12 pairs
4 Major Parts of Brain
Cerebrum / Diencephalon / Brainstem / Cerebellum
Cerebrum
largest; “seat of intelligence”
allows higher cognitive function, integrate info from receptors, process visual info and higher order visual info, …
allows us to do “figure things out”
ex) read, write, speak, calculate, compose, remember past, plan for future, imagine things…
Layers of Cerebrum (superficial to deep)
Cerebral Gyrus
Cerebral Sulcus
Cerebral Cortex (Gray Matter)
Cerebral White Matter
Lobes of Cerebrum
Frontal / Parietal / Occipital / Temporal / Insula (deep)
3 Types of Tracts in Cerebral White Matter
Association Tract - communicate w/in same hemisphere
Commissural Tract - communicate across hemisphere
Projection Tract - communicate to/from lower part CNS
Limbic System (location / f(x))
“emotional brain”
just inferior to cerebrum
connect emotion to behavioral response
smell and memory
motivation, learning, transition of info from short to long-term memory
3 Parts of Diencephalon (~”deception”) and function
Thalamus
Hypothalamus
Epithalamus
relay and filter
Thalamus
principal relay station for sensory impulses going to cerebral cortex
Hypothalamus
controls many body activities, including regulating homeostasis
body temp, pituitary glands, emotion/behavioral patterns, eating/drinking, ANS, circadian rhythm
Epithalamus
2 parts:
Habenular Nuclei - emotional responses to odors
Pineal Gland - melatonin secretion
Cerebellum
lower walnut of the brain
controls fine and gross muscle coordination
“how well did that action get executed?”
3 Parts of Brainstem and general function
Midbrain
Pons
Medulla Oblongata
basic autonomic functions like reflex
Medulla Oblongata (location & functions)
superior part of spinal cord; inferior part of brainstem
cardiovascular center (HR & BP)
medullary respiration center
reflexes: vomiting, swallowing, sneezing, coughing, hiccup
CRANIAL NERVES 8 9 10 11 12
Pons (location & function)
superior to medulla; anterior to cerebellum
ventral region: efficiency of voluntary motor output
dorsal region: ascending (aff) and descending (eff) nerve fiber
pontine respiratory group
CRANIAL NERVES 5 6 7 8
Midbrain (location & functions)
superior portion of brainstem
relay for impulses from cerebral cortex to pons and spinal cord
motor activity and muscular tone
CRANIAL NERVES 3 4
Reticular Formation (location and function)
extends from spinal cord into diencephalon
Reticular Activating System (RAS) ascending portion: managing consciousness, arousal, alertness, sensory overload prevention; inactivated for sleep; damaged leads to coma
RAS descending portion: connection to cerebellum and spinal cord; regulate muscle tone, HR, BP, RR
3 Layers of Meninges
dura mater
arachnoid mater
pia mater
3 Extensions of Dura Mater
Falx Cerebri: separates 2 hemispheres of CEREBRUM
Falx Cerebelli: separates 2 hemispheres of CEREBELLUM
Tentorium Cerebelli: separates cerebrum from cerebellum
Blood-Brain Barrier
extra measure of brain protection from harmful substances
mainly tight junctions
semipermeability controlled by Astrocytes
O2 CO2 caffeine nicotine H2O - easy
glucose - easy with facilitated transport
water solubles like ions - slow
Cerebrospinal Fluid (CSF) (location and function)
ventricles and subarachnoid space
-mechanical protection
-chemical protection
-circulation
what % of O2 and glucose consumed in brain?
20% even at rest
Types of brain hemorrhage
epidural
sudural
suarachnoid
intracerebral
Olfactory Nerve (#,from?,type,function,test)
(I)
cerebelum
sensory
conduct nerve impulses for smell
asking able-to question of common things like alcohol wipe
Optic Nerve (#,from?,type,function,test)
(II)
cerebrum
sensory
conduct nerve impulses for vision
can you read what it says?
Oculomotor Nerve (#,from?,type,function,test,muscles)
(III)
midbrain
motor
move eyes + eyelid muscles / pupillary constriction
H test
medial rectus / superior rectus / inferior rectus / inferior oblique
Trochlear Nerve (#,from?,type,function,test,muscles)
(IV)
midbrain
motor
move eyes
H test
superior oblique (connected to trochlea, the “pulley”)
Abducens Nerve (#,from?,type,function,test,muscles)
(VI)
pons
motor
move eyes
H test
lateral rectus (it’s going to “abduct” the eyeball)
Trigeminal Nerve (#,from?,type,function,test)
(V)
pons
V1 Ophthalmic - sensory
V2 Maxillary - sensory
V3 Mandibular - both
facial sensation and chewing
sensation test; clinch test
Facial Nerve (#,from?,type,function,test)
(VII)
pons
both
facial expression, salivation, tears, blinking, taste: sweet/salty, 2/3 anterior tongue
let’s see you smile, frown; any issues with eating recently?;
Vestibulocochlear Nerve (#,from?,type,function,test)
(VIII)
medulla
sensory
vestibular - equilibrium; cochlear - hearing
ability to walk; finger rub
Glossopharyngeal Nerve (#,from?,type,function,test)
(IX)
medulla
both
swallowing, taste: bitter/sour, posterior 1/3 tongue, gag reflex
look for lifting of uvula
Vagus Nerve (#,from?,type,function,test)
(X)
medulla
both
swallowing, gag reflex, sensation behind ear, innervation pharynx and epiglottis, parasympathetic innervation of organs in thorax and abdomen
?
Accessory Nerve (#,from?,type,function,test)
(XI)
medulla
motor
movement of trapezius and sternocleidomastoid muscle
turn head to shoulders; shoulder shrug with resistance
Hypoglossal Nerve (#,from?,type,function,test)
(XII)
medulla
motor
tongue movement
pay attention to their pronunciation
