Immune System

Question 1

spleen is the location of…

Answer 1

blood storage and activation of B-cells, which turn into plasma cells and produce antibodies

Question 2

humoral immunity

Answer 2

B-cells leave spleen and enter blood circulation as naive cells that have not been exposed to an antigen

also antibody driven

Question 3

t-cells

Answer 3

• mature in the thymus, small gland in front of the pericardium
• cell-mediated immunity
• directly kill virally infected cells

Question 4

lymph nodes

Answer 4

• immune cells use these as a location to communicate and plan an attack
• B-cells activated here as well

Question 5

GALT

Answer 5

• tonsils
• adenoids in the head
• peyer’s patches in the small intestine
• lymphoid aggregates in the appendix

Question 6

granulocytes

Answer 6

• contains granules effective in eliminated bacterial, fungal, and parasitic pathogens
• NEB

Question 7

agranulocytes

Answer 7

• lack granules
• monocytes, phagocytic cells, become macrophages in tissues such as microglia, Langerhans cells in skin, osteoclasts in bone)
• lymphocytes, antibody, targeted killing

Question 8

defensins

Answer 8

antibacterial cells found on skin

Question 9

lysozyme

Answer 9

• nonspecific bacterial enzyme found in mucous membranes

Question 10

complement system

Answer 10

• nonspecific
• found in blood, consist of a lot of proteins
• activated either through pathogen-antibody binding (classical) or alternatively
• punch holes through bacteria cell walls making them osmotically unstable

Question 11

interferons

Answer 11

• produced by cells that have been infected by a virus
• prevent replication and dispersion
• dec cell permeability
• upregulate MHC class I and class II

Question 12

cytokines

Answer 12

released by macrophages and stimulate inflammation and recruit other immune cells

Question 13

MHC

Answer 13

• after a macrophage performs endocytosis and breaks down an invader, the MHC will bind to the peptide antigens and present them to the cell surface to trigger other cells of the adaptive immune system

innate

Question 14

MHC-I

Answer 14

• all nucleated cells in the body display these molecules
• any protein produced within a cell can be loaded onto MHC-I and presented on the surface of the cell
• endogenous pathway bc it binds antigens that come from inside the cell
• T-cells can then kill them

innate

Question 15

MHC-II

Answer 15

• displayed by professional antigen presenting cells like macrophages
• pick up pathogens from environment and present them on MHC-II
• exogenous pathway bc antigens originate from outside the cell
• may initiate both innate and adaptive immunity
• include macrophages, dendritic cells in skin, some B-cells, certain activated epithelial cells

innate

Question 16

pattern recognition receptors

Answer 16

• special receptors known as PRR
• best-described toll-like receptors
• able to recognize the category of invader bacterium, virus, fungus, or parasite
• allows for production of appropriate cytokines

innate

Question 17

NK cells

Answer 17

• innate
• nonspecific lymphocyte
• able to detect down regulation of MHC and induce apoptosis in these virally infected cells
• often offer protection from the growth of cancer as well

Question 18

granulocytes

Answer 18

• N: most populous leukocyte in blood, short-lived, phagocytic, target bacteria using chemotaxis, detect bacteria once they’ve been opsonized (marked w antibody from B-cell), contain receptors for antibodies and can attack opsonized bacteria, dead neutrophil is pus
• E: allergic rxn, invasive parasitic infection, release large amounts of histamines inc blood vessel leakiness and vasodilation, inflammation
• B: allergic responses, least populous in bloodstream, mast cells are closely related to these but exist in tissues and mucosa and epithelium, both releases histamines and lead to inflammatory response

innate

Question 19

antibodies

Answer 19

• aka immunoglobulins
• can be present on cell surface or secreted into bodily fluids
• Y-shaped
• 2 heavy chains and 2 light chains, which are held together by disulfide linkages and noncovalent interactions
• antigen-binding regions at the end of which is called the variable region and the tips of the Y
• bind specific polypeptide sequences

Question 20

why does it take so long for the antibody response to begin?

Answer 20

• B-cells undergo hypermutation of its antigen-binding region, providing a vehicle for clonal selection
• remaining part of the antibody is known as the constant region

Question 21

Naive B-cells in immunity

Answer 21

• sit in the lymph nodes awaiting exposure to the correct antigen
• primary response produces the plasma cells which die eventually and the memory B-cells which last a lifetime, takes 10 days
• secondary exposure extreme rapid proliferation thanks to the memory B-cells
• vaccination

Question 22

During maturation in the thymus, T-cells undergo both

Answer 22

positive and negative selection

Question 23

positive selection

Answer 23

• allowing only the maturation of cells that can respond to the presentation of antigen on MHC

Question 24

negative selection

Answer 24

• causing apoptosis in cells that are self-reactive

Question 25

thymosin

Answer 25

• maturation of T-cells
• peptide hormone secreted by thymic cells
• once a T-cell leaves the thymus it is mature but naive
• upon antigen exposure, clonal selection only highest affinity proliferate

Question 26

lymphokines

Answer 26

• helper t cells
• respond to antigens on MHC-II molecules
• recruit others
• loss of this is HIV

Question 27

cytotoxic t cells

Answer 27

• directly killing virally infected cells by injecting chemicals promoting apoptosis
• T-cells respond to antigens presented on MHC-I molecules

Question 28

suppressor T-cells

Answer 28

• can be differentiated from helper T-cells bc they also express Foxp3 to tone down immune response and prevent autoimmune disease

Question 29

memory T-cells

Answer 29

• similar to memory B-cells
• lie in wait until the next exposure to the same antigen
• carry out robust and rapid response

Question 30

bacterial infection

Answer 30

• macrophage eat bacteria
• inflammation
• present antigens and cytokines attract neutrophils and macrophages
• mast cells activate by inflammation and degranulate, resulting in histamine release and inc leakiness of the capillaries
• dendritic cells alert B cells in lymph nodes which then produce antibody response, also activate helper T cells to activate macrophages to eat tagged bacteria

Question 31

viral infection

Answer 31

• cell produces interferons
• reduce permeability transcription translation of nearby cells
• symptoms begin
• MHC-I process occurs
• cytotoxic T cells recognizes MHC-I and promote apoptosis

Question 32

self-antigen

Answer 32

protect cell from autoimmunity

Question 33

hypersensitivity reactions

Answer 33

allergies and autoimmunity

Question 34

why are glucocorticoids so efficient in treating autoimmune diseases?

Answer 34

they have immunosuppressive qualities

Question 35

lymph join to form…

Answer 35

the thoracic duct

Question 36

the thoracic duct delivers fluid to…

Answer 36

the left subclavian vein

Question 37

lymph nodes contain…

Answer 37

a lymphatic channel, artery, and vein

Question 38

lymph nodes function to…

Answer 38

provide a space for the cells of the immune system to be exposed to possible pathogens

Question 39

edema

Answer 39

swelling due to fluid collecting in tissue

Question 40

lacteals

Answer 40

• small lymphatic vessels located at the center of each villus in the small intestine
• fats packaged as chylomicrons by intestinal mucosal cells enter lácteas for transport
• whitish lymphatic fluid full of chylomicrons are called chyle

Question 41

germinal centers

Answer 41

collections of B-cells in lymph nodes to proliferate and mature

Question 42

which cells produce antibodies?

Answer 42

plasma cells