Introduction

Question 1

what are leukocytes?

Answer 1

WBCs

Question 2

what are the 3 general layers of protection of the immune system

Answer 2

external defenses- physical barriers
innate immunity
adaptive immunity

Question 3

define antigen

Answer 3

a molecule that can be recognized by the immune system

Question 4

define immunogen

Answer 4

an antigen the induces an immune response

Question 5

define humoral immunity

Answer 5

mediated by antibodies

Question 6

define cellular immunity

Answer 6

mediated by cells

Question 7

passive vs active immunity

Answer 7

passive- immunity established by a transfer of antibodies or lymphocytes
active- immunity as a result of the hosts response

Question 8

pattern recognition receptors

Answer 8

bind to patterns found directly on microorganisms and are expressed on many different cell types. nonspecific

Question 9

describe the innate immune system

Answer 9

relies on mechanisms present prior to infection. provides a rapid response regardless of past exposure

consists of acute phase proteins, complement, macrophages, PMNs, and NK cells

Question 10

what are the stages of an immune response?

Answer 10

recognition
activation
clonal expansion
effector phase
establishment of memory

Question 11

name some potent APCs

Answer 11

macrophages, B cells, dendritic cells

Question 12

describe what MHCs are and the different subtypes

Answer 12

cell surface proteins that bind to antigens and present them to TCRs. there are 2 types

class 1- found on all nucleated cells and present peptides from internal peptides
class 2- found on APCs and present peptides from externally derived proteins

Question 13

what are the 2 important charactersitics of adaptive immunity

Answer 13

specificity and memory

Question 14

describe receptor cross linking

Answer 14

in order to simulate cells via anitgen-specific receptors, multiple receptors on the cell surface need be activated simultaneously. APCs have their receptors in close proximity on the cell surface, allowing them to co-ligand, which also brings kinases and signaling molecules close together internally

Question 15

two signal activation

Answer 15

two signals are required for immune activation to prevent inappropriate activation.

signal 1 is the immune receptor (TCR or Ig)

signal 2 is provided a costimulatory signal induced by danger signals

Question 16

difference between primary and secondary lymphoid tissue

Answer 16

primary- where lymphocytes develop (thymus)

secondary- where mature lymphocytes reside and responses are mounted

Question 17

tolerance

Answer 17

the process that ensures that lymphocytes only respond to foreign antigens by removing autoreactive lymphocytes