Microbiology, Immunology and Physiology Flashcards
chloramphenicol is used to treat…
streptococcus infection and haemophilus
fuisidic acid is most indicated for which organisms
staph aureus
gentamicin is treatment for
pseudomonas
anti-fungals and what they’re used for
ganiciclovir- dendritic ulcers
oxytetracycline- conjucntivial chlamydia
name some physical and chemical properties of tears
physical- anti-adhesive
chemical- lysozyme
some cells in tears
neutrophils, macrophages, conjunctival mast cells
langerhans cells are rich in
MHC class 2 (present to APCs and create CD4+> helper Ts)
where are langerhans cells abundant
limbus
what is the only part of the eye with lymphatic drainage
conjunctiva
what are cornea and sclera innervated with
V1
what does the retina, vitreous and choroid have
blood-ocular barrier
the eye has ______ ________ which means…
immune privilege, can tolerate antigens but don’t elicit a huge response
what allows immune privilege to occur in the eye
- blood-ocular barrier
- immunosuppressive molecules/ inhibitory cell surface molecules
- anterior-chamber associated immune deviation
know what sympathetic ophthalmia is
AI bilateral granular uveitis to ocular antigens
CSF is produced by _____ cells in the _____ plexus
ependymal cells in choroid plexus
transport of CSF?
produced by choroid plexus at each ventricle > 3rd ventricle > down aqueduct into 4th ventricle > subarachnoid space > spinal cord
what ions move from blood to CSF
Na, Cl, HCO3-
what are 3 functions of CSF
- mechanical support to brain
- homeostatic function
- circulation/ exchange of nutrients
what is the blood brain barrier’s main function
to protect brain against infection
what does aqueous humour buffer
has HCO3- so buffers H+ produced by cornea
what is normal intra-ocular pressure
17mmHg
each eye has _____ vision but because 2 ____ visions overlap we perceive it as _____
monocular, monocular, binocular
layer 4C of visual cortext (parietal lobe) has….
columns- these are dominated by input from 1 of the 2 eyes
Hebb’s postulate…
when layer 4c columns are repeatedly stimulated by one eye so can only see from 1 eye
what do photoreceptors do?
concert electromagnetic radiation to neural signals
layers of photoreceptor
rods/cones> body of cell> synaptic terminal
describe the process of phototransduction
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)
desrcibe phototrasnduction using rods as an example
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
Rods…
allow to see in dim light
sparsely spaced > large ganglion cell > high convergence (low acuity)
cones…
allow to see colour
high density > few per ganglion cell> low convergence (high acuity)
what are the 3 opsins for wavelengths
blue=short
green=medium
red= long
