CSF and BBB

Question 1

What cells make the outer and inner layer of the arachnoid mater?

Answer 1

Outer= barrier
Inner= trabecular

Question 2

Name the 3 forms of cerebral haemorrhage?

Answer 2

Outside dura= epidural
Between dura and arachnoid= subdural haemorrhage
Inside arachnoid space= subarachnoid

Question 3

Signs/ symptoms of epidural haemorrhage?

Answer 3

Arterial usually

No initial symptoms, but then severe headache as haematoma compresses brain

Question 4

Signs/ symptoms of subdural haemorrhage?

Answer 4

Occurs in bridging veins, so onset symptoms slow.

Imaging shows blood spread diffusely across brain surface

Question 5

Signs/ symptoms of subarachnoid haemorrhage?

Answer 5

Ruptured aneurysm

Sudden, sevvere headache

Question 6

How does epidural bleed occur in MRI?

Answer 6

Lens shaped

Question 7

What is meant by lucid interval?

Answer 7

In epidural bleed, patients may regain consciousness briefly only to descend into unconciousness again

Question 8

What is the falx?

Answer 8

Where the dura descends down between hemispheres, dividing them and forming a sheet (falx)

Question 9

Where does the falx make a T junction with occipital dura?

Answer 9

At occipital pole

Question 10

What are the tentoria?

Answer 10

Pair of transvere sheets of dura extending laterally below base of occipital cerebelum

Question 11

What do you call the gap between the two tentorii?

Answer 11

Tentorial incisure

Question 12

What passes through the tentorial incisure?

Answer 12

Brainstem

Question 13

What are the four ventricles of the brain

Answer 13

Lateral ventricles (1&2)
Third ventricle
Fourth ventricle

Question 14

What forms CSF?

Answer 14

Choroid process

Question 15

What is the choroid process?

Answer 15

Meshwork of capillaries covered by ependymal cells protruding into the ventricles of the brain

Question 16

Which ventricle contains majority of choroid process

Answer 16

Lateral ventricles

Question 17

Why do small changes in blood pCO2 cause large changes into csf pH?

Answer 17

Healthy CSF contains little protein and no cells so is not pH buffered in the same way as blood

Question 18

At what rate is CSF produced?

Answer 18

500ml/day

Question 19

How much CSF is held in the brain?

Answer 19

135-150ml/day

Question 20

How is CSF drained from the lateral ventricles into the blood?

Answer 20

From lateral to 3rd and 4th to cisterna magna to subarachnoid space
Absorbed into arachnoid granulations and joins venous blood in superior sagittal sinus

Question 21

What is hydrocephalus?

Answer 21

Accumulation of CSF in the ventricular system

Question 22

What causes hydrocephalus?

Answer 22

obstruction of normal CSF circulation with consequent dilation of ventricles
usually due to blockage in cerebral aqueduct

Question 23

3 main functions of astrocytes

Answer 23

maintain local pH and glucose
remove excess NT, metabolites
secrete growth factors/ cytokines

Question 24

How do astrocytes respond to CNS injury?

Answer 24

Proliferate to form astrocytic site

Question 25

Proper names of grey matter and white matter astrocytes

Answer 25

Grey: protoplasmic astrocytes
White: Fibrous astrocytes

Question 26

What are end feet?

Answer 26

The processes of astrocytes end in expansions called end feet

Question 27

Function of tight junctions in brain capillaries

Answer 27

Prevent exit of proteins

Question 28

What makes up the blood brain barrier?

Answer 28

Astrocyte end feet and tight junction system

Question 29

Where do arachnoid granulations penetrate the dura?

Answer 29

At the top of the brain

Question 30

What is the superior sagittal sinus

Answer 30

Vein running sagitally along midline

Question 31

What veins run into the skull

Answer 31

Diploid

Question 32

What is a common cause of epilepsy?

Answer 32

Malfunction of the glial cells in region where an infract or other neuronal insult has occured

Question 33

What molecules can pass the blood brain barrier unaided?

Answer 33

Lipid-soluble molecules such as opiates