Immunology

Question 1

what is the function of the blink reflex

Answer 1

production of tears
flushes out debris
mucous layer provides anti-adhesive layer to the eye

Question 2

list some of the chemical properties of the eye surface

Answer 2

lysozyme destroys bacterial cell wall
lactoferrin and transferrin targets gram +ve bacteria
angiogenin provides antimicrobial effects within tear film
secretory IgA
complement system

Question 3

list some of the immune cells of the eye and their functions

Answer 3

neutrophils - attracted by chemotaxis
macrophages - phagocytosis of damaged cells and triggers adaptive immune system
conjunctival mast cells - vasoactive mediators

Question 4

what is the function of the langerhan cells and where in the eye are they found

Answer 4

principle antigen presenting cell for the eye

highly abundant at corneoscleral limbus, less in peripheral cornea and absent in central 1/3 of the cornea

Question 5

which part of the eye is the only part with lymphatic drainage

Answer 5

conjunctiva

Question 6

describe the immunology makeup of the cornea and sclera

Answer 6

tough collagen coat, avascular, no lymphoid tissue and only Langerhan cells in peripheral cornea

Question 7

describe immune privilege

Answer 7

certain sites of the body that are able to tolerate introduction of antigens without eliciting an inflammatory response

Question 8

list the sites of the eyes that have immune privilege

Answer 8

cornea
anterior chamber 
lens 
vitreous cavity 
subretinal space

Question 9

list the mechanisms of immune privilege

Answer 9

blood tissue barrier and lack of lymphatic drainage
ocular microenvironment rich in immunosuppressive molecules
surface molecules that influence the reactivity of immune cells
anterior chamber associated immune deviation

Question 10

what is anterior chamber associated immune deviation

Answer 10

placement of foreign antigen in ocular microenvironment can induce a systemic form of tolerance to foreign antigens