immune system p.III

Question 1

cellular (cell-mediated) immune response

Answer 1

antigen presenters for T cell maturation are:

1. dendritic cells
2. macrophages
3. B cells

t cells must recognize self + nonself and form clones like in B cells but with different classes

Question 2

t cell clones: helper T cells

Answer 2

circulate through body to recruit other immune cells

interacts with B cells and push them into rapid clone production and signal for antibody production to begin

Question 3

helper T cells release lymphokines that

Answer 3

act indirectly to rid body of antigens by

1. stimulating cytotoxic T cells + B cells to grow and divide
2. attracting other types of protective WBCs in the area
3. enhancing ability of macrophages to engulf, destroy microorganisms

Question 4

t cell clones: cytotoxic T cells

Answer 4

specialize in killing virus-infected, cancer, or foreign graft cells

do this by binding to them and inserting toxin perforin into invader cell membrane

target cell ruptures and cytotoxic T cell attacks others

Question 5

t cell clones: supressor/regulatory T cells

Answer 5

release chemicals to supress activity of T + B cells

vital for ending immune response after antigen destructure so no autoimmune stuff’

few members of each clone are memory cells

Question 6

organ transplants + rejection

Answer 6

for those w/ end-stage heart disease or kidney disease organ transplants are desirable

may compromise immune system tho’

4 types of grafts

Question 7

autografts

Answer 7

tissue transplanted from one site to another
on the same person

ideal + sucessful w/ adequate blood supply + no infection

Question 8

isografts

Answer 8

tissue grafts from a genetically identical
person (identical twin)

ideal + sucessful w/ adequate blood supply + no infection

Question 9

allografts

Answer 9

tissue taken from individuals that are not
genetically identical but belong to the same species

used from tissue/organs of recently dead people
ABO + other antigens of donor + recepient must be matched at least 75% but is hard to find in non-related ppl

Question 10

xenografts

Answer 10

tissue taken from a different animal species

whole organs are never successful, but pig heart valves work

Question 11

graft preventative measures

Answer 11

immunosupressive therapy is given after surgery to prevent rejection

Question 12

examples of immunosupressive therapy

Answer 12

corticosteroids for less inflammation
cytotoxic drugs
radiation therapy
immunosupressor drugs

these kill rapidly dividing cells (lymphocytes) and have major side effects

cause patient to be very exposed to bacteria + viruses

Question 13

allergies/hypersensitivities

Answer 13

abnormally vigorus immune responses where immune system causes tissue damage due to autoimmune issues

most common type ois immediate hypersensitivity

Question 14

allergen

Answer 14

antigen that triggers hypersensitivity

Question 15

immediate hypersensitivity

Answer 15

triggered by release of histamine due to IgE binding to mast cells

Question 16

histamine

Answer 16

causes small blood vessels to become dilated which causes hives
runny nose, watery eyes, itching

Question 17

asthma

Answer 17

when allergen is inhaled symptoms appead because SMM in walls of bronchioles contracts –> constricting passages and restricting air flow

Question 18

anaphylatic shock

Answer 18

fairly rare body wide or systemic acute allergic response

occurs when allergen directly enters blood and circulates rapidly through body

since entire body is involved, it is life threatening

Question 19

causes and effects of anaphylactic shock

Answer 19

certain bee stings, spider bites, injection of haptens

difficulty breathing when SMM of lungs contract, lung passages contract, sudden vasodilation + fluid loss, circulatory collapse, death within mins

Question 20

epinephrine

Answer 20

drug of choice to reverse histamine mediated effects

Question 21

delayed hypersensitivity

Answer 21

not histamine mediated
rather reaction mediator is lymphokines from activated T cells

1-3 days after contact, corticosteroid drugs are used for relief

Question 22

allergic contact dermatitis

Answer 22

skin contact w/ poison ivy,, heavy metals like lead/mercury, cosmetic + deodorant chemicals that act as haptens and are diffused through skin

Question 23

mantoux, tine, skin tests for TB detection

Answer 23

depend on delayed hypersensitivity reaction

when antigens are injected just under skin, small hard lesion forms if person has been sensitized

Question 24

immunodeficiencies

Answer 24

can be congenital or acquired

production or function of immune cells or complement is abnormal

Question 25

severe combined immunodeficiency disease SCID

Answer 25

most severe congenital
deficit of B + T cells

bc T cells are necesasry for normal operation of both arms of immune response, afflicted children have no protection against any pathogens

minor infections are letal

bone marrow transplants or umbilical cord blood (have normal lymphocyte stem cells) can help but patients have to live in a protected environment

Question 26

acquired immune deficiency syndrome AIDS

Answer 26

most severe acquired

cripples immune system by interfering in activity of helper T cells

Question 27

autoimmune disease

Answer 27

when immune system loses ability to tolerate self antigens and attack foreign antibodies

body produces autoantibodies and sensitized T cells that attack and damage its own tissues

Question 28

multiple sclerosis AID

Answer 28

white matter (myelin sheaths) of brain and spinal cord are destroyed

Question 29

myasthenia gravis AID

Answer 29

impairs communication between nerves and SKM

Question 30

graves disease AID

Answer 30

thyroid gland produces excessive amounts of thyroxine

Question 31

juvenile diabetes AID

Answer 31

destroys pancreatic beta cells that produce insulin

Question 32

rheumatoid arthritis AID

Answer 32

destroys joints

Question 33

cause of autoimmune disease or self-tolerance breakdown

Answer 33

3 reasons that trigger normal state of self-tolerance to break down

Question 34

1. inefficient lymphocyte programming

Answer 34

instead of being destroyed, self reactive B and T lymphocytes just move somewhere else

Question 35

2. appearance of self-proteins in circulation that have not been exposed to immune system

Answer 35

hidden antigens are found in eggs, sperm, eye lens, certian proteins in thyroid gland

new self antigens may appear as a result of gene mutations or alteration in self-proteins by hapten attachment or by bacteria/viral damage

Question 36

3. cross reaction of antibodies produced against foreign antigens with self-antigens

Answer 36

ex. antibodies produced during an infection caused by streptococcus bacteria can cross react with heart antigens and cause damage to heart muscle, valves,joints, kidneys

known as rheumatic fever

Question 37

developmental aspects of lymphatic system + body defenses

Answer 37

lymphoid organs are poorly developed before birth except for thymus + spleen

newborn only has passive immunity from mother, no functioning lymphocytes

if lymphatics are removed or lost, severe edema, but vessels grow back in time