Physiology

Question 1

Where is CSF produced?

Answer 1

Secretory epithelium of the choroid plexus (found within the ventricles)

Question 2

Where does CSF travel to beyond the ventricles?

Answer 2

Circulates in the subarachnoid space and absorbed in the venous circulation

Question 3

What are the three major functions of the CSF?

Answer 3

Mechanical protection

Homeostatic function

Circulation

Question 4

Describe the homeostatic function of CSF

Answer 4

pH affects pulmonary ventilation and cerebral blood flow/ transports hormones

Question 5

What can a lumbar puncture aid to diagnose?

Answer 5

Pathology in the brain, meninges and spinal cord

Question 6

Describe the components of normal CSF?

Answer 6

Clear and colourless

Contains (14-45mg/dl)

Little immunoglobulins

1-5cells/ml

Question 7

At three weeks the developing nervous system consists of

Answer 7

Neural canal

Question 8

What does the cavity of the neural canal give rise to?

Answer 8

Adult brains ventricles and the spinal cords central canal

Question 9

Where does the choroid plexus develop from?

Answer 9

Cells in the walls of the ventricles

Question 10

What forms the choroid fissure?

Answer 10

Developing arteries invagination the roof of the ventricle

Question 11

Which ventricles can choroid plexi be found in?

Answer 11

3rd, 4th and lateral ventricles

Question 12

What ions are transported across the epithelium from blood to CSF in CSF production?

Answer 12

Na
Cl
HCO3

Question 13

What does secretion of CSF from the choroid plexus depend upon?

Answer 13

Active transport of Na across cells into CSF

Question 14

What is the intraventricular foramina (of monroe)?

Answer 14

Lateral ventricles to third ventricle

Question 15

What is the cerebral aqueduct of sylvius?

Answer 15

Third to fourth ventricle

Question 16

What is the foramen of megendie?

Answer 16

Median aperture- fourth ventricle to subarachnoid space

Question 17

What is the foramen of luschka?

Answer 17

Lateral apertures- fourth ventricle to subarachnoid space

Question 18

CSF enters the subarachnoid space through

Answer 18

pores

Question 19

Which ventricle is CSF formed in?

Answer 19

Lateral ventricles

Question 20

Describe the path of CSF from the lateral ventricle

Answer 20

Alows to third ventricle through the interventricular foramina
more CSF is added by chroroid plexus in roof of third ventricle
flows through the aqueduct of midbrain (cerebral aqueduct)
and into the fourth ventricle
another choroid plexus in fourth ventricle adds more CSF
CSF then enters the subarachnoid space (between pia and dura mater) through three openings in rood of fourth ventricle
single median aperture
paired lateral apertures
then circulates in the central canal in the spinal cord

Question 21

How does CSF return to the venous blood?

Answer 21

arachnoid granulations into the superior sagittal sinus

Question 22

The blood CSF barrier is

Answer 22

leaky

Question 23

What does the BBB consist of?

Answer 23

capillary endothelium, basal membrane and perivascular astrocytes

Question 24

What is the role of tight junctions in BBB

Answer 24

Prevent paracellular movement of molecules

Question 25

Which parts of the brain lack BBB

Answer 25

Circumventricular organs or pineal gland

Question 26

What does the BBB protect against?

Answer 26

common bacterial infections and toxins

Question 27

What is the main barrier for drug delivery to the CNS?

Answer 27

BBB

Question 28

What tumours can be found in the ventricles, choroid plexus?

Answer 28

Colloid cyst: interventricular foramen Ependymomas: ependymal cells lining ventricles Choiroid plecus tumours

Question 29

What kinds of haemorrhage cause accumulation of blood in the ventricles?

Answer 29

Epidural haematoma Subdural Haematoma Subarachnoid haemorrhage

Question 30

What is an epidural haematoma?

Answer 30

Arterial bleed between skull and dura

Question 31

What is a subdural haematoma?

Answer 31

venous bleed between dura and arachnoid

Question 32

What is hydrocephalus?

Answer 32

Accumulation of CSF in the ventricular system or around the brain

Question 33

What is idiopathic hypertension/pseudotumour cerebri

Answer 33

Increased CSF pressure with no imaging features of hydrocephalus

Question 34

What are the symptoms of pseudo tumour cerebri?

Answer 34

Headache | Visual disturbances

Question 35

What does aqueous humor provide?

Answer 35

Oxygen, metabolites, bicarbonate

Question 36

What is the purpose of bicarbonate in aqueous?

Answer 36

Buffers the H+ produced in the cornea and lens by anaerobic glycolysis

Question 37

What is the role of ascorbate in the aqueous?

Answer 37

Powerful antioxidant

Question 38

Describe the path of aqueous ?

Answer 38

Produced by ciliary body in posterior chamber of eye Flows into anterior chamber and drains into scleral venous sinus through a trabecular meshwork and the canal of schlemm A small amount is passed into vitreous

Question 39

Where is the canal of schlemm situated?

Answer 39

Iridocorneal angle

Question 40

What is the pigmented epithelium?

Answer 40

Faces the blood inside the ciliary epithelium

Question 41

What is the non-pigmented epithelium?

Answer 41

Lined the inside of the retina and generates aqueous humour

Question 42

What blocks the production of aqueous?

Answer 42

Carbonic anhydrite inhibitors

Question 43

How do carbonic anhydrase inhibitors work?

Answer 43

Prevents the transport of cl and Na into the cell

Question 44

What causes the movement of water through aquaporins?

Answer 44

net trafficking of ions an osmotic gradient is generated causing the movement of water via aquaporins