6: Physiology I

Question 1

Where is CSF produced?

Answer 1

Choroid plexus in brain ventricles

Question 2

What is the normal volume of CSF?

Answer 2

150 ml

Question 3

Which space does the CSF circulate in?

Which circulation does it drain into?

Answer 3

Subarachnoid space

Venous circulation

Question 4

The CSF acts as a ___-absorber.

Answer 4

shock

Question 5

The CSF supplies the brain with ___ and removes ___.

Answer 5

nutrients

metabolites

Question 6

How can CSF be obtained to diagnose CNS diseases?

Answer 6

Lumbar puncture

Question 7

Normal CSF is (clear / coloured).

Answer 7

coloured

Question 8

What is the embryological origin of the nervous system?

Answer 8

Neural tube

Question 9

The ___ ___ secretes CSF and is found in the walls of the ___.

Answer 9

choroid plexus

ventricles

Question 10

What structure is formed by arteries invaginating the neural tube and is the origin of the choroid plexus?

Answer 10

Choroid fissure

Question 11

The choroid plexus is highly ___.

Answer 11

vascular

Question 12

CSF is produced by the choroid plexus and passes into the ___ before passing into the subarachnoid space.

Answer 12

bloodstream

Question 13

Which ions need to be transported into epithelial cells to trigger CSF release?

Answer 13

Na⁺

HCO₃^-

Cl^-

Question 14

Secretion of CSF is dependent on the transport of ___ and ions into epithelial cells.

Answer 14

water

Question 15

Sodium is (actively / passively) transported into epithelial cells of the choroid plexus.

Answer 15

actively transported

Question 16

Which ventricles of the brain release CSF?

Through which structures does the CSF then pass into the subarachnoid space?

Answer 16

Lateral ventricles

Third ventricles

Fourth ventricles

Medial and lateral apertures

Question 17

Once CSF has passed through the medial and lateral apertures and circulated in the subarachnoid space, where does it drain?

Answer 17

Dural venous sinus

Question 18

What is the name given to the thick endothelium found in the capillaries of the brain?

Answer 18

Blood brain barrier

Question 19

Which type of junction prevents molecules e.g toxins from passing through the blood brain barrier?

Answer 19

Tight junctions

Question 20

Why is it difficult to deliver drugs directly to the brain?

Answer 20

Blood brain barrier

Question 21

Anything causing ___ in the cranial cavity can cause increased intra-___ pressure.

Answer 21

swelling

increased intra-cranial pressure

Question 22

What is hydrocephalus?

Answer 22

Accumulation of CSF in brain (caused by improper secretion or drainage) causing an increase in intracranial pressure

Question 23

What happens to the ventricles in hydrocephalus?

Answer 23

Hypertrophy

Question 24

What symptoms are produced by intracranial hypertension?

Answer 24

Headache

Papilloedema (swelling of optic disc causing visual disturbance)

Question 25

Which nerve, important for vision, is included in the **subarachnoid space**?

Answer 25

**CN II**

Question 26

What is **papilloedema**?

Answer 26

**Optic disc swelling** due to **increased intracranial pressure**

Question 27

What causes of **increased intracranial pressure** can cause papilloedema?

Answer 27

**Hydrocephalus** **Swelling** (tumours, hypertrophy)

Question 28

What particular **visual disturbances** can be caused by **papilloedema**?

Answer 28

**Enlarged blind spot** **Blurry vision** **Visual loss**

Question 29

What fluid does the **ciliary body** produce?

Answer 29

**Aqueous humour**

Question 30

Where in the eye does **aqueous humour** circulate?

Answer 30

**Anterior chamber**

Question 31

What is the purpose of **aqueous fluid**?

Answer 31

**Nourishes structures of anterior chamber**

Question 32

Which structure does **aqueous humour** drain into? Where exactly is this found?

Answer 32

**Scleral venous sinus** **Iridocorneal angle**

Question 33

What particular layers of the ciliary body produce **aqueous humour**?

Answer 33

**Pigmented epithelium** **Non-pigmented epithelium** (outer)

Question 34

Which ions are transported into pigmented -\> non-pigmented epithelial cells to trigger production of aqueous fluid?

Answer 34

**Na**⁺ **Cl**^-

Question 35

Which enzyme helps Na+ and Cl- transport into ciliary body cells?

Answer 35

**Carbonic anhydrase**

Question 36

Which contransporter is important in the transport of ions into the anterior chamber?

Answer 36

**Na**+/**K**+/**2Cl**- cotransporter

Question 37

Inhibitors of which enzyme decrease aqueous fluid production?

Answer 37

**Carbonic anhydrase**

Question 38

What are some examples of **carbonic anhydrase** inhibitors?

Answer 38

**Dorzolamide** **Acetazolomide**

Question 39

Overproduction of aqueous fluid causes **raised** ____ \_\_\_, which can cause which disease?

Answer 39

**raised intraocular pressure** **glaucoma**

Question 40

Which drugs are used to treat glaucoma? How do they work?

Answer 40

**Carbonic anhydrase inhibtors** Reduce secretion of aqueous fluid, reducing intraocular pressure

Question 41

CSF concentration determines intra-\_\_\_ pressure. Aqueous fluid concentration determines intra-\_\_\_ pressure.

Answer 41

**CSF** - intra-cranial pressure **Aqueous fluid** - intra-ocular pressure