Intro to Immunology

Question 1

innate immunity

Answer 1

immediate protection against microbial invasion

always present in healthy individuals

blocks and eliminates microbes

Question 2

adaptive immunity

Answer 2

develops slowly and provides more specialized defense against infections

differentiation and expansion of lymphocytes in response to microbes

Question 3

cells involved in innate immunity

Answer 3

epithelial barriers

mast cells

phagocytes

complement system proteins

NK (natural killer) cells and ILCs (innate lymphoid cells)

Question 4

cells involved in adaptive immunity

Answer 4

B lymphocytes

T lymphocytes

Effector T cells

Plasma cells

cells produce antibodies

Question 5

Lymphocytes

Answer 5

cells of adaptive immune system

have clonal distributed receptors with fine specificities for different antigens

Question 6

humoral immunity

Answer 6

type of adaptive immunity that uses excreted antibodies to neutralize and eradicate extracellular microbes and toxins

Question 7

cell-mediated immunity

Answer 7

type of adaptive immunity in which T-lymphocytes eradicate intracellular microbes (those that have been phagocytosed or viruses replicating inside of infected cells)

Question 8

Sequential phases of adaptive immune response

Answer 8

antigen recognition by lymphocytes ->

activation of lymphocytes to proliferate and differentiate into effector and memory
cells ->

elimination of microbes ->

decline of response ->

long-lived memory

Question 9

what are the only cells that produce antibodies?

Answer 9

B lymphocytes

Question 10

plasma cells

Answer 10

progeny of B lymphocytes that secrete antibodies that neutralize and eliminate antigens

Question 11

function of B lymphocyte antibodies expressed on membrane

Answer 11

recognize antigen

Question 12

T lymphocytes

function?
types?

Answer 12

important for viral, fungal, and intracellular bacterial pathogens.

recognize protein antigens presented by MHC molecules

CD4 - helper cells
CD8 - killer cells
T-regs - regulator cells

Question 13

Helper T cells

Answer 13

produce cytokines that activate phagocytes and destroy ingested microbes, recruit leukocytes, and activate B lymphocytes to produce antibodies

Question 14

cytotoxic T lymphocytes

Answer 14

kill infected cells harboring microbes in the cytoplasm

Question 15

Antigen-presenting cells (APCs)

Answer 15

capture antigens of microbes that enter through epithelia, concentrate these antigens in lymphoid organs, and display the antigens for recognition by T cells

Question 16

location of native lymphocytes

Answer 16

circulate through peripheral lymphoid organs looking for foreign antigens

Question 17

location of effector T lymphocytes

Answer 17

migrate to peripheral sites of infection to eliminate microbes

Question 18

location of plasma cells

Answer 18

remain in lymphoid organs and bone marrow - antibodies they secrete enter circulation to find and eliminate microbes

Question 19

peripheral lymphoid organs

Answer 19

lymph nodes, spleen, mucosal and cutaneous immune systems - located in and under the epithelia of the skin and the gastrointestinal and respiratory tracts

Question 20

Cells that are part of the lymphoid lineage during hematopoiesis

Answer 20

natural killer cells, T and B lymphocytes, plasma cells

Question 21

cells that are part of the myeloid lineage in hematopoiesis

Answer 21

ertythrocytes, platelets, basophils, neutrophils, eosinophils, monocytes (become macrophages, dendritic cells)

Question 22

difference between myelocytic cell maturation and lymphoid cell maturation

Answer 22

myelocytic cells mature in the bone marrow

lymphoid cells develop n the lymphoid organs: thymus, lymph nodes, spleen.

Question 23

in what type of marrow does hematopoiesis occur? what is the other type made up of?

Answer 23

red marrow, yellow marrow is made up of inactive adipocytes

Question 24

what happens to the red/yellow marrow ratio as we age?

Answer 24

start out with 100% red marrow, gradually move toward mix of red and yellow marrow

Question 25

what does a high reticulocyte count indicate?

Answer 25

anemia b/c the body is making lots of new RBCs to make up for anemia

Question 26

what is indicated by a shift towards high numbers of bands and other immature neutrophils in peripheral blood?

Answer 26

significant immune stressor

Question 27

phagocytes

Answer 27

engulf and digest pathogens, initiate inflammation, trigger adaptive immune system

includes macrophages, neutrophils, and dendritic cells

most effective against bacterial and fungal pathogens, as viruses are too small and parasites are too big

Question 28

innate lymphocytes

Answer 28

natural killer cells, intraepithelial lymphocytes (IEL)

scan for normal cells and kill abnormal/infected/mutated cells

Question 29

complement proteins

Answer 29

serum proteins that are activated by presence of pathogens and start an enzymatic cascade that results in immune/inflammatory response and lysis of bacterial pathogen.

Question 30

defensins

Answer 30

small peptides with anti-microbial activity found in intestinal secretions and body fluids

Question 31

pattern recognition receptor (PRR)

Answer 31

pre-formed receptors that bind to structures present on pathogens but not human cells - pathogen associated molecular patterns (PAMPs)

Question 32

epitope

Answer 32

specific part of an antigen recognized by specialized receptors

Question 33

clone

Answer 33

group of lymphocytes that arise from a single common precursor and recognize a specific and distinct antigen

Question 34

Langerhans Cells

Answer 34

present in the skin - epidermis

phagocytose antigens

presents antigens to T cells after migrating to lymph nodes

Question 35

how do antigens and antibodies find each other?

Answer 35

antigens leak through the capillary walls into the lymph fluid and are transported into lymph nodes where they are trapped

Question 36

where in the body is the largest single accumulation of lymphocytes? why?

Answer 36

the spleen - filters blood

Question 37

function of cytokines

Answer 37

provide instructions for immune cells regarding the type of infection and what the immune cells should do

Question 38

chemokines

Answer 38

small cytokines that signal nearby cells to move