Microbiology, Immunology and Physiology

Question 1

chloramphenicol is used to treat…

Answer 1

streptococcus infection and haemophilus

Question 2

fuisidic acid is most indicated for which organisms

Answer 2

staph aureus

Question 3

gentamicin is treatment for

Answer 3

pseudomonas

Question 4

anti-fungals and what they’re used for

Answer 4

ganiciclovir- dendritic ulcers

oxytetracycline- conjucntivial chlamydia

Question 5

name some physical and chemical properties of tears

Answer 5

physical- anti-adhesive

chemical- lysozyme

Question 6

some cells in tears

Answer 6

neutrophils, macrophages, conjunctival mast cells

Question 7

langerhans cells are rich in

Answer 7

MHC class 2 (present to APCs and create CD4+> helper Ts)

Question 8

where are langerhans cells abundant

Answer 8

limbus

Question 9

what is the only part of the eye with lymphatic drainage

Answer 9

conjunctiva

Question 10

what are cornea and sclera innervated with

Answer 10

V1

Question 11

what does the retina, vitreous and choroid have

Answer 11

blood-ocular barrier

Question 12

the eye has ______ ________ which means…

Answer 12

immune privilege, can tolerate antigens but don’t elicit a huge response

Question 13

what allows immune privilege to occur in the eye

Answer 13

1. blood-ocular barrier
2. immunosuppressive molecules/ inhibitory cell surface molecules
3. anterior-chamber associated immune deviation

Question 14

know what sympathetic ophthalmia is

Answer 14

AI bilateral granular uveitis to ocular antigens

Question 15

CSF is produced by _____ cells in the _____ plexus

Answer 15

ependymal cells in choroid plexus

Question 16

transport of CSF?

Answer 16

produced by choroid plexus at each ventricle > 3rd ventricle > down aqueduct into 4th ventricle > subarachnoid space > spinal cord

Question 17

what ions move from blood to CSF

Answer 17

Na, Cl, HCO3-

Question 18

what are 3 functions of CSF

Answer 18

1. mechanical support to brain
2. homeostatic function
3. circulation/ exchange of nutrients

Question 19

what is the blood brain barrier’s main function

Answer 19

to protect brain against infection

Question 20

what does aqueous humour buffer

Answer 20

has HCO3- so buffers H+ produced by cornea

Question 21

what is normal intra-ocular pressure

Answer 21

17mmHg

Question 22

each eye has _____ vision but because 2 ____ visions overlap we perceive it as _____

Answer 22

monocular, monocular, binocular

Question 23

layer 4C of visual cortext (parietal lobe) has….

Answer 23

columns- these are dominated by input from 1 of the 2 eyes

Question 24

Hebb’s postulate…

Answer 24

when layer 4c columns are repeatedly stimulated by one eye so can only see from 1 eye

Question 25

what do photoreceptors do?

Answer 25

concert electromagnetic radiation to neural signals

Question 26

layers of photoreceptor

Answer 26

rods/cones> body of cell> synaptic terminal

Question 27

describe the process of phototransduction

Answer 27

in the dark the membrane is depolarised as Na+ channels are open, when light is introduced there is conformational changes and membrane becomes hyper polarised (Na+ channels close)

Question 28

desrcibe phototrasnduction using rods as an example

Answer 28

rhodopsin (retinal and opsin)- light changes 11-cis-retinal to all-trans retinal > opsin changes conformation > triggers a signal transduction cascade > closure of cGMP gated Na+ channels

Question 29

Rods…

Answer 29

allow to see in dim light

sparsely spaced > large ganglion cell > high convergence (low acuity)

Question 30

cones…

Answer 30

allow to see colour

high density > few per ganglion cell> low convergence (high acuity)

Question 31

what are the 3 opsins for wavelengths

Answer 31

blue=short
green=medium
red= long