Anatomy Head and Neck

Cranium is broken into 2 parts

Neurocranium - top of skull; calvaria (hat) and cranial base
viscerocranium - bottom where jaw is

Fontanelles

soft spots in infants because cranium hasn’t been fully formed

Pterion

frontal, parietal, temporal, and sphenoid bone meets here. Very weak. Middle meningeal artery is here

Lamda

lambdoid and sagittal suture

Bregma

Coronal and sagittal suture

Asterion

lambdoid and squamous suture

Sella turcica

Clinoid processes and hypophysial fossa

Foramen cecum

nasal emissary veins

Cribriform foramina

olfactory nerves (CN I)

Optic Canals

Optic nerves (CN II)
Ophthalmic arteries

Superior orbital fissures

Ophthalmic veins
Trigeminal - Ophthalmic nerve (CN V1)
Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Abducens nerve (CN VI)

Foramen rotundum

Trigeminal - Maxillary nerve (CN V2)

Foramen ovale

Trigeminal - Mandibular nerve (CN V3)
Accessory meningeal artery

Foramen spinosum

middle meningeal artery and vein
Trigeminal - Meningeal branch of mandibular (CN V3)

Foramen lacerum

gets filled as we age

Internal acoustic meatus

Facial nerve (CN VII)
Vestibulocochlear nerve (CN VIII)

Jugular foramen

Glossopharyngeal nerve (CN IX)
Vagus nerve (CN X)
Spinal accessory nerve (CN XI) (exits)
Internal petrosal and sigmoid sinuses become internal jugular vein

Hypoglossal canal

Hypoglossal nerve (CN XII)

Foramen magnum

medulla
meninges
vertebral arteries
spinal accessory nerve (CN XI) (enters)
Dural veins
anteiror and posterior spinal arteries

Carotid canal

internal carotid artery

stylomastoid foramen

facial nerve (CN VII)
stylomastoid artery

Meninges

dura mater
arachnoid mater
pia mater

Dura mater

innervated
vascular → middle meningeal artery
2 layers: external periosteal layer (stuck to skull) and internal meningeal layer (forms dural infolds and stuck to brain)

arachnoid mater

not innervated / not vascular
bridging veins

Pia mater

innervated
vascular → cerebral arteries and veins

Falx cerebri

crista galli to occipital protuberance

Tentorium Cerebelli

Clinoid processes (sphenoid) petrous part of temporal bone to occipital / parietal bones

Falx cerebelli

occipital bone - tentorium cerebelli

Diaphragma sellae

roof over hypophyseal fossa (sphenoid)

Meningeal spaces

Epidural space: not a natural space
Dura mater: subdural space: not a natural space
Arachnoid mater: subarachnoid space: CSF
Pia mater: no space

Hemorrhage

excessive bleeding

Hematoma

clot

Epidural (extradural) hemorrhage

Middle meningeal artery → supplies blood to dura mater
trauma

subdural hematoma

“bridging” veins (cerebral and cerebellar veins) → cross subdural space to drain superficial brain into venous sinuses
trauma

subarachnoid hemorrhage

cerebral arteries → supply cerebrum
aneurysm

Petrosal sinuses

superior petrosal sinus drains into transverse sinus
inferior petrosal sinus drains into internal jugular vein

Cavernous sinuses

Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Trigeminal - Ophthalmic branch (CN V1)
Trigeminal - Maxillary branch (CN V2)
Internal carotid artery
abducens nerve (CN VI)
trochlear nerve (CN IV)
OTO MCAT

Blood supply to meninges

external carotid artery → maxillary artery → middle meningeal artery

Meningitis

viral infection, bacterial, or fungal
symptoms: headache, fever, vomiting, nuchal ridigity (stiff neck)
neck flexion test

Cerebrospinal fluid

Formation: choroid plexus
Ependymal cells: neuroglial cells, helps protect brain, filtering systems, pulls plasma from blood into ventricular system
flow: ventricles makes CSF mostly in lateral ventricles

Flow of CSF

Lateral ventricles → interventricular foramen → third ventricle → cerebral aqueduct → fourth ventricle → lateral / medial apertures → subarachnoid space and central canal in spinal cord

Subarachnoid cisterns

extended regions of subarachnoid space with pockets of CSF to help with bounancy

Arachnoid granulations

super sagittal sinus has the most
drain CSF from subarachnoid space into bloodstream

Hydrocephalus

blockage of CSF flow causes enlargement of ventricles behind the blockage

Pre central gyrus

motor

post central gyrus

sensory

somatosensory

whole body sensory: feel your tongue

Nuceli

collection of somas in central nervous system (brain and spinal cord)

ganglia

collection of somas in peripheral nervous system

nerve

collection of axons in peripheral nervous system

tract

collection of axons in central nervous system

White matter vs. gray matter

white matter: axons
gray matter: somas

Commissural tracts

connect different hemispheres

Association tracts

stays in the same hemisphere

Projection tracts

connects superior / inferior, up and odwn

Broca’s area

production of speech, making words, etc

Wernicke’s area

Comprehension of speech; being able to understand

Aphasia

disorder that affects how you communicate

Basal nuclei / ganglia

caudate nucleus, putamen, globus pallidus
filters unwanted movement ex: resting tremors: hand shaking at rest is an unwanted movement

Telencephalon

amygdala: emotional responses related to memory
hippocampus: memory
cingulate gyrus: regulating behavior response regarding to emotion
controls emotional response and memory processing

Hypothalamus

integration center for autonomic nervous system ex: temperature, thirst
regulation of endocrine system; hypothalamus tells pituitary gland what to do

Pituitary gland

hormones

Pineal gland

regulates circadian rhythm

Midbrain

Relay center that connects different structures; communicating
superior colliculus - visual reflex center
inferior colliculus - auditory reflex center

Pons

projection fibers connect higher brain centers and spinal cord
relay impulses between motor cortex and cerebellum
changes respiratory rate, but doesn’t start it

Medulla oblongata

heart rate
respiratory rate (starts it)
blood pressure
vomiting
coughing
nuclei of cranial nerves