Cranial Systems

Question 1

Choroid plexus

Answer 1

part of the lateral ventricle

produce majority of CSF

Question 2

interthalamic adhesion

Answer 2

tissue bridge that crosses third ventricle and links two thalami

Question 3

granular foveolae

Answer 3

larger granulations which have eroded adjacent bone resulting in pits on the inferior portion of the skull.

Question 4

hydrocephalus

Answer 4

water on the brain; enlargement of one or more of the ventricles due to a blockage in the ventricular system.

Question 5

Most common site of ventricular blockage

Answer 5

cerebral aqueduct as it is the most narrow region

stenosis of cerebral aqueduct results in enlargement of lateral ventricle and third ventricle

Question 6

3 layers of cranial meninges.

also list the new one

Answer 6

dura mater: periosteal layer (outer) + meningeal layer (contains sinuses)

arachnoid mater: contains CSF and cerebral vasculature

pia mater: clings to brain and divdes into the sulci

Subarachnoid lymphatic-like membrane (SLYM): fourth meningeal layer that separates arachnoid mater into two functional compartments. Serves like a barrier. Contains a large population of immune cells

Question 7

leptomeninges

Answer 7

refers to both arachnoid and pia mater

Question 8

cranial meninges

Answer 8

overlie and surround the brain layers

Functions: vascular, homeostatic, structural/protective

Question 9

dural folds

Answer 9

places where the meningeal layer of the dura mater reflect away from the external periosteal layer

Function: contain venous sinuses to facilitate CSF drainage; divide up the cranial cavity into sections to provide structural support for compartments

part of the dura mater

Question 10

List and describe the 2 large dural folds

What is a significant area of the second large dural fold?

Answer 10

1. Falx cerebri: divides the left and right cerebral hemisphere. Lies in the sagittal plane
2. Tentorium cerebelli: overlies cerebellum

Lies in transverse plane

Attaches at the edges of posterior cranial fossa

Tentorial notch: allows for the passage of the brainstem through the tentorium cerebelli; exists at the anteriomedial border of the tentorium cerebelli

Question 11

List and describe the 2 small dural folds

Answer 11

1. Falx cerebelli: divides the left and right cerebellar hemispheres; lies inferior to the tentorium cerebelli
2. Diaphragma sellae (or sellar diaphragm): roof over hypophyseal fossa of sphenoid bone; encloses pituitary stalk and separates pituitary gland from inferior portion of cerebrum

Question 12

How do the venous sinuses differ from the regular veins?

Answer 12

contain blood from the brian and skull

Have no tunica media or valves

Question 13

Trace blood flow from the superior and inferior sinuses to the internal jugular sinus

Answer 13

Superior sagittal sinus → torcular herophili (aka confluence of sinus) → transverse sinus → sigmoid sinus →jugular foramen → internal jugular sinus

Inferior sagittal sinus → straight sinus → torcular herophili (confluence of sinus) → transverse sinus → sigmoid sinus → jugular foramen → internal jugular sinus

Question 14

ischemic stroke

Answer 14

clot/ air bubble is blocking flow to an area of the brain

If you have an ischemic stroke, you have a time window where you can give a clot buster (TPA). This may unblock artery and restore oxygen supply

Question 15

hemorrhagic stroke

Answer 15

bleeding inside or around brain tissue; bursting of blood vessel

You do not want to administer a clot buster for a hemorrhagic stroke. This will make bleeding difficult to stop

Question 16

The majority of strokes are what kind of strokes?

Answer 16

middle cerebral artery strokes (51%)