Physiology

Question 1

name the main component of CSF

Answer 1

water

Question 2

where is CSF produced?

Answer 2

secretory epithelium of the choroid plexus

Question 3

where does the CSF circulate?

Answer 3

subarachnoid space

Question 4

where is CSF absorbed?

Answer 4

venous circulation

Question 5

name the 3 major functions of CSF

Answer 5

mechanical protection
homeostatic function
circulation

Question 6

clinical CSF analysis is obtained via what?

Answer 6

lumbar puncture

Question 7

where in the brain is the choroid plexus found?

Answer 7

3rd, 4th and lateral ventricles

Question 8

name the 4 ventricles

Answer 8

2 lateral ventricles
third ventricle
fourth ventricle

Question 9

what connects the lateral and third ventricle?

Answer 9

foramen of Monroe

Question 10

what connects the third and fourth ventricle?

Answer 10

cerebral aqueduct

Question 11

the foramen of Magendie is found on the ______ aperture connecting the fourth ventricle to the subarachnoid space whereas the foramina of _______ is found on the lateral apertures connecting the fourth ventricle to the subarachnoid space.

Answer 11

the foramen of Magendie is found on the MEDIAN aperture (single) connecting the fourth ventricle to the subarachnoid space whereas the foramina of LUSCHKA is found on the lateral apertures (pair) connecting the fourth ventricle to the subarachnoid space.

Question 12

the subarachnoid space is found between the ___ and ____ _____

Answer 12

the subarachnoid space is found between the PIA and DURA MATER

Question 13

name the following tumour pathology of the ventricles, choroid plexus and CSF:

(a) found at interventicular foramen
(b) arising from the ependymal cells lining the ventricles

Answer 13

(a) colloid cyst
(b) ependymomas

also choroid plexus tumours

Question 14

name the following definitions:

(a) accummulation of blood in the ventricles
(b) arterial bleed between skull and dura
(c) venous bleed between dura and arachnoid

Answer 14

(a) ventricular haemorrhage
(b) epidural hematoma
(c) subdural hematoma

Question 15

the following definitions describe what pathology:

accumulation of CSF in the ventricular system or around the brain (either due to obstruction or overproduction)

subsequent enlargement of one or more ventricles and increase in CSF pressure

Answer 15

hydrocephalus

Question 16

name the enigmatic condition causing headache and visual disturbances but no imaging features of hydrocephalus despite increased CSF

Answer 16

idiopathic intracranial hypertension

Question 17

define papilloedema

Answer 17

optic disc swelling due to increased intracranial pressure transmitted to the subarachnoid space surrounding the optic nerve

Question 18

list the visual symptoms of a patient with papilloedema

Answer 18

enlarged blind spot
blurring of vision
visual obscurations
vision loss

Question 19

what does aqueous humour contain?

Answer 19

bicarbonate

Question 20

where is aqueous humour made? what chamber is this in?

Answer 20

epithelial layer of the ciliary body in posterior chamber of the eye

Question 21

where does aqueous humour drain once in the anterior chamber of the eye?

Answer 21

scleral venous sinus through a trabecular meshwork and the angle of Schlemm

Question 22

what drug reduces production of aqueous humour and is used to reduced ocular pressure in glaucoma?

Answer 22

carbonic anhydrase inhibitors -

dorzolamide (eye drops) avoiding systemic effects

acetazolomide (oral) also targets kidneys leading to acidosis

Question 23

name the 3 cells in the direct vertical pathway for signal transmission

Answer 23

photoreceptors to bipolar cells to ganglion cells

Question 24

what cells receive input from photoreceptors and project to other photoreceptors and bipolar cells?

Answer 24

horizontal cells

Question 25

what cells receive input from bipolar cells and project to ganglion cells, bipolar cells, and other amacrine cells?

Answer 25

amacrine cells

Question 26

photoreceptors convert ________________ radiation to ______ signals

Answer 26

photoreceptors convert ELECTROMAGNETIC radiation to NEURAL signals

Question 27

name the 2 types of photoreceptors

Answer 27

rods and cones

Question 28

name the 4 main regions of photoreceptors

Answer 28

outer segment inner segment cell body synaptic terminal

Question 29

with light exposure, Vm ________________!

Answer 29

with light exposure, Vm HYPERPOLARIZES!

Question 30

name the visual pigment molecules in rods

Answer 30

rhodopsin and opsin

Question 31

what converts 11-cis-retinal to all-trans-retinal?

Answer 31

light

Question 32

lowered Na entry results in __________________

Answer 32

lowered Na entry results in HYPERPOLARIZATION

Question 33

there is more _________ in the dark and less of it in the light

Answer 33

there is more GLUTAMATE in the dark and less of it in the light

Question 34

define visual acuity

Answer 34

ability to distinguish 2 nearby points

Question 35

what is visual acuity determined by?

Answer 35

photoreceptor spacing and refractive power

Question 36

rods/cones are for seeing in dim light and rods/cones are for seeing in normal daylight

Answer 36

``` rods = dim cones = normal ```

Question 37

there is more convergence in ___ system, increasing sensitivity while decreasing ______

Answer 37

there is more convergence in ROD system, increasing sensitivity while decreasing ACUITY

Question 38

name the colour for the following cones: (a) short WL - (b) middle WL - (c) long WL -

Answer 38

(a) short WL - BLUE (b) middle WL - GREEN (c) long WL - RED

Question 39

what is the following explaining: ``` achromatic peripheral retina high convergence high light sensitivity low visual acuity ```

Answer 39

rods

Question 40

what is the following explaining: ``` chromatic central retina (fovea) low convergence low light sensitivity high visual acuity ```

Answer 40

cones