Meninges, Ventricular System, CSF

Question 1

What are the 3 layers of the meninges?

Answer 1

Dura, Arachnoid and Pia maters

Question 2

Describe the 3 layers of the Dura mater.

Answer 2

1. Periosteal: Closely adhered to the calvarium
2. Meningeal: Forms infoldings
3. Dural border cells

Question 3

What is the function of the falx cerebri?

Answer 3

Occupies the longitudinal fissure between the hemispheres and encloses the superior sagittal sinus.

Question 4

Where is the Tentorium cerebelli?

Answer 4

Sits between the cerebrum and posterior fossa

Question 5

What separates the two cerebellar hemispheres?

Answer 5

Falx cerebelli

Question 6

What is the main blood supply to the meninges?

Answer 6

Middle meningeal artery

Question 7

Discuss the Dural venous sinuses

Answer 7

1. Located between the periosteal and meningeal layers of the dura mater.
2. Provide venous drainage for brain with blood and CSF leading into IJV.
3. No valves

Question 8

Discuss Subdural hematomas

Answer 8

1. Occurs between dura and arachnoid resulting from head trauma.
2. Bridging veins are torn in plane of dural border cells.

Question 9

Describe the location and characteristics of Arachnoid mater.

Answer 9

1. Between dura and pia
2. CSF located in subarachnoid space
3. CSF flows from the SAS into the dural venous sinuses through the arachnoid villi

Question 10

Discuss the mechanism of transfer regarding CSF and arachnoid villi

Answer 10

CSF can move through the arachnoid villi intercellularly or mediated transport through cells

Question 11

Discuss Subarachnoid hemorrhage

Answer 11

Bleeding in the subarachnoid space

Question 12

Describe the pia mater

Answer 12

A thin layer of CT that closely adheres to the surface of the brain and spinal cord. Also projects into fissures and sulci.

Question 13

Where are you most likely to find CSF?

Answer 13

Subarachnoid space = 20%

Ventricular system = 80%

Question 14

Why is CSF important?

Answer 14

Due to the fact that there is no lymphatic system in the brain, it helps remove toxins.

Question 15

Where is CSF produced?

Answer 15

In the choroid plexus. Lateral ventricles and the roofs of the 3rd and 4th ventricles

Question 16

How is CSF secreted?

Answer 16

Regulated by a sodium-potassium ATPase. Carbonic anhydrase inhibitors can decrease sodium exchange and thus decrease CSF secretion

Question 17

Describe CSF

Answer 17

Acellular; No rbc or wbc

Question 18

Discuss Hydrocephalus

Answer 18

An enlargement of the ventricles, two types: Communicating and Non-communicating

Question 19

Discuss Communicating hydrocephalus

Answer 19

Ventricular system communicates with SAS. There is a blockage of CSF resorption in the SAS

Question 20

Discuss Non-communicating hydrocephalus

Answer 20

Ventricular system does not communicate with the SAS. There is a block between the lateral ventricles and the SAS