NeuroAnatomy - Lecture Four Objectives - Ventricular System, CSF, and BBB

Question 1

What is the ventricular system?

Answer 1

cavities within the brain/spinal cord that circulate CSF

Question 2

What are all of the cavities of the ventricular system?

Answer 2

lateral ventricles, foramen of Monro, third ventricle, cerebral aqueduct, fourth ventricle, and central canal of spinal cord

Question 3

What is the Cerebral Spinal Fluid Pathway?

Answer 3

Lateral ventricles –> Foramen of Monro –> 3rd ventricle –> cerebral aqueduct –> 4th ventricle –> foramen of Luschka and R/L lateral foramen of Magendie –> subarachnoid space of brain & central canal of spinal cord –> dural sinuses –> venous system

Question 4

What is the function of the CSF?

Answer 4

protects the brain, removes waste products from metabolism, provides stable environment for interstitial fluid of brain tissue

Question 5

What is the total quantity of circulating CSF and what is the turn over rate?

Answer 5

150ml, turns over about 4x/day

Question 6

What does the CSF flow pressure gradient allow?

Answer 6

allows CSF to flow from arachnoid granulations into venous sinuses – opens when subarachnoid space is 1mmHg greater than the dural sinus pressure

Question 7

What produces CSF?

Answer 7

choroid plexus

Question 8

What is the blood brain barrier?

Answer 8

Interface between brain capillaries and brain tissue that protects the CSF from systemic circulation

Question 9

What are the 4 functions of the Blood Brain Barrier?

Answer 9

1. Monitor nutrients that CNS
2. Monitor electrolyte balance of CNS
3. Prevents circulating transmitters from entering CNS
4. Prevent toxins, large molecules, and water-soluble molecules from CNS