ANATOMY FINAL GOOD

What is the outermost meningeal layer?

Dura mater

What does the dura mater adhere to?

Inner surface of the cranium

What are dural infoldings?

Extensions of dura that support and stabilize the brain

What is the falx cerebri?

Dural fold separating the cerebral hemispheres

What is the tentorium cerebelli?

Dural fold separating cerebrum from cerebellum

What are dural venous sinuses?

Venous channels that drain blood from the brain

Where do dural venous sinuses drain?

Internal jugular vein

What is the superior sagittal sinus?

Midline sinus draining superior brain

What is the transverse sinus?

Drains posterior brain to sigmoid sinus

What is the straight sinus?

Drains deep brain structures

What is the confluence of sinuses?

Junction of major dural sinuses

What is the sigmoid sinus?

S-shaped sinus leading to internal jugular vein

What is the cavernous sinus?

Venous sinus beside sella turcica with cranial nerves

What is the basilar plexus?

Venous network connecting intracranial and vertebral veins

What are the petrosal sinuses?

Connect cavernous sinus to sigmoid sinus

What is the occipital sinus?

Small sinus in posterior cranial fossa

Where is the cavernous sinus located?

On either side of the sella turcica

What artery runs through the cavernous sinus?

Internal carotid artery

What cranial nerve runs through the cavernous sinus?

Abducens nerve (CN VI)

Which cranial nerves run in the wall of the cavernous sinus?

CN III, IV, V1, V2

Why is cavernous sinus infection dangerous?

Can affect multiple cranial nerves and ICA

What artery supplies the dura mater?

Middle meningeal artery

Where is the middle meningeal artery vulnerable?

Pterion

What is the arachnoid mater?

Middle meningeal layer

How is the arachnoid mater held against the dura?

CSF pressure

What connects arachnoid to pia?

Arachnoid trabeculae

What is the subarachnoid space?

Space containing CSF and cerebral arteries

What is the pia mater?

Innermost meningeal layer

What is unique about the pia mater?

Highly vascular and adheres to brain surface

What does the pia mater follow?

Gyri and sulci contours

Which meningeal layer is pain-sensitive?

Dura mater

What causes headaches related to meninges?

Vessel distension or dura irritation

How can cancer spread via meninges?

Through dural venous sinuses and vertebral plexus

Is the epidural space in the skull a real space?

No (potential space)

Is the subdural space a real space?

No (potential space)

Which meningeal space is real?

Subarachnoid space

What causes an epidural hematoma?

Rupture of middle meningeal artery

Where does epidural hematoma commonly occur?

Pterion

What is a subdural hematoma caused by?

Rupture of bridging veins

What is a subarachnoid hemorrhage?

Bleeding into subarachnoid space (often aneurysm)

Why are intracranial hemorrhages dangerous?

Can lead to death within hours

What are gyri?

Brain folds

What are sulci?

Shallow grooves

What are fissures?

Deep grooves

What are the cerebral hemispheres?

Two halves of cerebrum

What are the four main lobes?

Frontal, parietal, temporal, occipital

What is the diencephalon?

Central brain region (thalamus, hypothalamus)

What does the epithalamus contain?

Pineal gland

What is the thalamus function?

Sensory relay center

What is the hypothalamus function?

Homeostasis and endocrine control

What is the midbrain?

Rostral part of brainstem

What is the pons?

Middle brainstem (anterior posterior fossa)

What is the medulla oblongata?

Controls vital functions (caudal brainstem)

Where is the cerebellum located?

Posterior to pons/medulla, under tentorium

What are the ventricles of the brain?

Lateral (2), third, fourth

Where is CSF produced?

Choroid plexus

How does CSF exit the ventricles?

Median and lateral apertures

Where does CSF go after ventricles?

Subarachnoid space

How is CSF reabsorbed?

Arachnoid granulations into venous sinuses

What is hydrocephalus?

Excess CSF causing ventricular dilation

Why do infant skulls expand in hydrocephalus?

Sutures not fused

Where does CSF leak with middle cranial fossa fracture?

Ear

Where does CSF leak with anterior cranial fossa fracture?

Nose

Why is CSF leakage dangerous?

Increased risk of meningitis

What % of body mass is the brain?

~2%

What % of blood supply does it receive?

~17%

What are the two main arterial sources to the brain?

Internal carotid and vertebral arteries

What do internal carotid arteries branch into?

Anterior and middle cerebral arteries

What do vertebral arteries form?

Basilar artery

What does the anterior cerebral artery supply?

Medial frontal and parietal lobes

What does the middle cerebral artery supply?

Lateral cerebral hemispheres

What does the posterior cerebral artery supply?

Occipital lobe and inferior brain

What is the Circle of Willis?

Arterial anastomosis at base of brain

What arteries form the Circle of Willis?

ACA, ACom, ICA, PCom, PCA

Why is the Circle of Willis important?

Provides collateral blood flow

What is an ischemic stroke?

Blocked blood flow (embolus/thrombus)

What is a hemorrhagic stroke?

Bleeding in brain

What is a berry aneurysm?

Weak arterial outpouching (Circle of Willis)

What does the occipitofrontalis do?

Raises eyebrows and wrinkles forehead

What are its two bellies?

Frontal and occipital

What does orbicularis oculi do?

Closes eyelids

What does orbicularis oris do?

Closes lips

What does the buccinator do?

Compresses cheek (keeps food between teeth)

What is the function of the platysma?

Tenses neck skin and depresses mandible

What nerve provides sensory innervation to the face?

Trigeminal nerve (CN V)

What nerve provides motor innervation to facial expression muscles?

Facial nerve (CN VII)

What nerve provides motor to muscles of mastication?

Mandibular nerve (V3)

What is the main arterial supply to the face?

External carotid artery

What artery supplies the lips?

Superior and inferior labial arteries

What artery supplies the nose?

Lateral nasal artery

What artery is palpated as the temporal pulse?

Superficial temporal artery

Where is the facial pulse palpated?

Inferior border of mandible

What arteries supply the scalp?

Occipital, posterior auricular, superficial temporal

What arteries from internal carotid supply the forehead?

Supraorbital and supratrochlear arteries

Where do facial veins drain?

Internal jugular vein

What is the largest salivary gland?

Parotid gland

What duct drains the parotid gland?

Parotid duct

What nerve provides parasympathetic innervation to parotid?

Glossopharyngeal nerve (CN IX)

What provides sympathetic innervation to parotid?

External carotid plexus

What is the temporal fossa?

Depression above zygomatic arch