Ventricular System Flashcards Preview

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Flashcards in Ventricular System Deck (16)
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1
Q

Where is CSF located?

A

Within sub-arachnoid space, cisterns and ventricles.

2
Q

What is CSF?

A

Clear, colourless, odourless fluid constantly produced and circulated within the CNS

3
Q

What is the function of CSF?

A

Protection

Buoyancy

Nutrient supply

Waste removal

Hormone transport

4
Q

How much CSF is produced daily?

A

450 - 600 ml/day = 0.5ml/min

5
Q

Where is CSF produced?

A

Choroid plexus in ventricles.

Choroidal arteries make specialised capillary loops in pia.

6
Q

How is CSF made?

A

Filtration of blood.

Sodium is actively transported into the CSF. Chlorine follows due to passive electrochemical attraction.

Osmotic pressure in CSF increases and water is pulled into CSF and K+ is pumped back into the blood

7
Q

How does CSF circulate within the CNS?

A

Initial production occurs in choroid plexus of lateral ventricles -> Intraventricular foramena of monroe -> 3rd ventricle (more choroid plexus) -> cerebral aqueduct of sylvius -> 4th ventricle -> Central canal of spinal cord -> lower dilated dead end of spinal cord (terminal ventricle)

8
Q

How does CSF exit the CNS?

A

It exits at 4th ventricle to enter dilated cisterns in subarachnoid space via lateral foramen Lushka -> cerebellopontine cistern -> posterior foramen magendie -> cerebellomedullary cistern then travels either superiorly under surface of cerebral hemispheres to reach the top or inferiorly around the pons, medulla, cerebellum, and spinal cord.

9
Q

What powers CSF movement?

A

hydrostatic pressure.

10
Q

How does CSF return to venous circulation?

A

Arachnoid villi -> Superior sagittal sinus -> falx cerebri -> transverse sinus -> sigmoid sinus -> jugular foramen -> internal jugular

11
Q

Where are lumbar punctures taken?

A

At the lumbar cistern at the level of L4/5.

12
Q

When should lumbar punctures not be taken?

A

High intracranial pressure

13
Q

What is hydrocephalus and what kinds are there?

A

Build up of CSF. Can be communicating or non-communicating

14
Q

What is the difference between communicating and non-communicating hydrocephalus?

A

Non-communicating: CSF from ventricular system can’t communicate with subarachnoid space.

15
Q

What causes non-communicating hydrocephalus?

A

Overproduction of CSF (rare choroid plexus papilloma)

Blocked foramen of monroe

Blocked cerebral aqueduct

Blocked foramen of Magendie/Lushka

16
Q

What causes communicating hydrocephalus?

A

Impaired arachnoid granulations (reduced resorption)

Meninges infection (scar formation can block subarachnoid space)

Thrombosed superior sagittal sinus (CSF can’t be drained)

Subarachnoid haemorrhage.