4.2 - Brain, brainstem, and cranial nerve

median longitudinal fissure

separates cerebral hemispheres

cerebral lobes

frontal, parietal, occipital, temporal

frontal lobe (gyrus, activity, region, function)

• precentral gyrus

• motor activity

• Prefrontal region

• Personality, complex
  thoughts, decision making

parietal lobe (sulcus, gyrus, cortex)

• central sulcus

• post-central gyrus

• somatic sensory cortex

occipital lobe cortex

primary visual cortex

temporal lobe (cortex + fissure)

primary auditory cortex, lateral fissure

brainstem parts

• diencephalon (hypothalamus + thalamus)

• midbrain (mesencephalon)

• pons (metencephalon)

• medulla oblongata (myelencephalon)

cerebellum other name

metencephalon

thalamus

relay b/w different parts of the brain, numerous nuclear groups

nucleus

collection of neuronal cell bodies

hypothalamus

regulates autonomic function, endocrine activity

midbrain functions and exits

process visual and auditory info, reflexes and consciousness, CN IV exits posteriorly

pons connection and cranial nerve

• cerebellum connects to brainstem

• CN: V, VI, VII, VIII

medulla oblongata functions and features

autonomic centers (respiratory and cardiac regulatory centers), olivary nuclei, pyramids

medulla oblongata cranial nervevs

glossophayngeal, vagus, spinal accessory, hypoglossal

cerebellum functions + neurons

adjust somatic motor output in brain + spine, coordinates complex somatic motor patterns, learning, 10% of brain mass but 50% of neurons

lateral ventricals number and connection

2 connect to 2 intraventricular foramen

third ventricle location, contains, connection

within diencephalon, contains choroid plexus which makes csf, cerebral aqueduct

fourth ventricle (formation, location, contains, connects)

forms roof of pons and medulla, deep to cerebellum, contains choroid plexus, connects to 2 lateral aperatures and median aperature

ventricles contain…

CSF

cerebral circle

anterior cerebral arteries, anterior communicating artery, internal carotid arteries, posterior communicating arteries, posterior cerebral arteries, penetrating branches supply deep structure

internal carotid arteries (branches in neck, enterance, passage, #)

2

no branches in neck

enters via carotid canal

passes through cavernous sinus

internal carotid arteries branches

opthalamic, posterior communication, anterior cerebral, middle cerebral

anterior cerebral artery (branch size, joining, distribution)

smaller terminal branch, anterior communicating artery connects right and left anterior cerebral, distribution: medial aspect of frontal and parietal lobes

middle cerebral arteries (size, continuaiton, supply)

larger branch, continuation of internal carotid, supplies lateral brain

vertebral arteries branch from and enterance

branch from subclavian artery

enter skull via foramen magnum

vertebral artery branches + # + size

anterior spinal (1)

posterior spinal (2)

posterior inferior cerebellar (2) - largest

basilar (1)

basilar artery formation and end

formed by vertebral arteries joining, ends anterior and superior to pons

branches of basilar artery

anterior inferior cerebellar, internal auditory, superior cerebellar, posterior cerebral

posterior cerebral artery passage and distribution

passes: lateral to midbrain

distributed on medial surface of occipital and temporal lobes

cranial nerve (pairs, system, passage)

12 pairs, in PNS except CNII, pass through foramina/fissures in cranium

Olfactory nerve function + origin

function: special sensory (smell = olfaction)

origin: olfactory epithelium inside superior nasal cavity

olfactory nerve foramen and destination

foramen: olfactory foramina on cribriform plate

destination: olfactory bulbs, tracts transfer info to the rest of the brain

olfactory nerve endings

small particles inhaled air stimulates sensory receptors

olfactory neurons

turn the stimulation into electrical signals, transmit it to the olfactory bulb/tract, then to the rest of brain

optic nerve (function, origin, foramen, destination, system)

function: special sensory (vision)

origin: retina

foramen: optic canal

destination: diencephalon, then to occipital lobe

part of CNS

oculomotor nerve function and innervation

controls extraocular eye muscles and parasympathetic innervation, muscles moving the eye and one eyelid muscle

oculomotor nerve and types of functions

somatic and visceral motor

oculomotor somatic motor

eye + eyelid movement

-superior, inferior, and medial rectus muscles

-inferior oblique muscle

-levator palpebrae superioris muscle

oculomotor visceral motor function

pupil constriction, lens convexity

oculomotor origin, foramen, destination

origin: mesencephalon (midbrain)

foramen: superior orbital fissure

destination: extra-ocular eye muscles (except two), ciliary body, pupillary muscles

trochlear nerve function, origin, foramen, destination

function: controls one extraocular eye muscle, origin: mesencephalon, foramen: superior orbital fissure, destination: superior oblique muscle

trochlear nerve type of function and innervation

somatic motor: eye movement, controls superior oblique muscle

trigeminal nerve function type and parts

mixed (general sensory and somatic motor)

-opthalmic (V1)

-maxillary (V2)

-mandibular (V3)

opthalmic (V1)

sensations from forehead, upper eyelid, nose

maxillary (V2)

sensations from lower eyelid, upper lip, and cheek

mandibular (V3)

sensations from lower jaw, controls mastication

trigeminal nerve origin

sensory: skin of face

somatic motor (V3): pons

trigeminal nerve foramen

(v1): superior orbital fissure

(v2): foramen rotundum

(v3): foramen ovale

trigeminal nerve destination

opthalmic, maxillary, and sensory part of mandibular pons

motor mandibular: jaw muscles-mastication

trigeminal nerve reminder

does not provide facial muscle function

abducens nerve function, origin, foramen, destination

function: somatic motor eye abduction - lateral rectus muscle

origin: pons

foramen: superior orbital fissue

destination: lateral rectus eye muscle

facial nerve function

mixed sensory and motor

special sensory: taste

somatic motor: controls muscles of facial expression

visceral motor: parasympathetic for eye, nose, mouth secretion

facial nerve origin

special sensory: taste buds on anterior 2/3 of the tongue

motor: pons and medulla

facial nerve foramen + branching

internal acoustic meatus

enters hole inside cranial cavity, branches in skull and exits via several holes

facial nerve destination

special sensory: medulla

motor: muscles of the face

visceral motor: lacrimal tear glands and small salivary glands

vestibulocochlear nerve function, origin, foramen, destination

function: special sensory-hearing and balance, origin: receptors of the vestibule and cochlea of ear, foramen: internal acoustic meatus, destination: pons

glossopharyngeal nerve function

general sensory: posterior 1/3 of tongue

special sensory: taste from posterior 1/3 tongue

visceral sensory: monitor blood pressure from internal carotid artery

somatic motor: 1 muscle

visceral motor: parasympathetic for saliva production

glossopharyngeal nerve origin

gen. + special sensory: posterior 1/3 of tongue

visceral sensory: carotid sinus, base of internal carotid artery

motor: pons and medulla

glossopharyngeal nerve foramen + destination

foramen: jugular foramen

destination: sensory-medulla, visceral motor-parotid salivary gland, somatic motor- stylopharyngeus muscle for swallowing

vagus nerve function

visceral sensory: visceral organ sensation (fullness, satiety, not pain)

visceral motor: parasympathetic innervation to the organs

somatic motor: conscious swallowing, vocalization

vagus nerve (origin, foramen, destination)

origin: sensory from organs, motor- medulla

foramen: jugular foramen

destination: sensor-medulla, visceral motor (respiratory, cardiovascular, digestive organs), somatic motor- muscles of palate, pharynx, larynx

spinal accesory nerve function, origin and foramen

function: somatic motor: neck movement and swallowing

origin: spinal cord and medulla

foramen: enters skull via foramen magnum, exits via jugular foramen

spinal accessory nerve destination

external branch: sternocleidomastoid and trapezius

internal branch: muscles of the palate, pharynx, and larynx

hypoglossal nerve function, origin, foramen, destination

function: motor-tongue movement, origin: medulla, foramen: hypoglossal canal, destination: tongue muscles