1
Q
spleen is the location of…
A
blood storage and activation of B-cells, which turn into plasma cells and produce antibodies
2
Q
humoral immunity
A
B-cells leave spleen and enter blood circulation as naive cells that have not been exposed to an antigen
also antibody driven
3
Q
t-cells
A
- mature in the thymus, small gland in front of the pericardium
- cell-mediated immunity
- directly kill virally infected cells
4
Q
lymph nodes
A
- immune cells use these as a location to communicate and plan an attack
- B-cells activated here as well
5
Q
GALT
A
- tonsils
- adenoids in the head
- peyer’s patches in the small intestine
- lymphoid aggregates in the appendix
6
Q
granulocytes
A
- contains granules effective in eliminated bacterial, fungal, and parasitic pathogens
- NEB
7
Q
agranulocytes
A
- lack granules
- monocytes, phagocytic cells, become macrophages in tissues such as microglia, Langerhans cells in skin, osteoclasts in bone)
- lymphocytes, antibody, targeted killing
8
Q
defensins
A
antibacterial cells found on skin
9
Q
lysozyme
A
- nonspecific bacterial enzyme found in mucous membranes
10
Q
complement system
A
- 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
11
Q
interferons
A
- produced by cells that have been infected by a virus
- prevent replication and dispersion
- dec cell permeability
- upregulate MHC class I and class II
12
Q
cytokines
A
released by macrophages and stimulate inflammation and recruit other immune cells
13
Q
MHC
A
- 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
14
Q
MHC-I
A
- 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
15
Q
MHC-II
A
- 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
16
Q
pattern recognition receptors
A
- 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
17
Q
NK cells
A
- 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
18
Q
granulocytes
A
- 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
19
Q
antibodies
A
- 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
20
Q
why does it take so long for the antibody response to begin?
A
- 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
21
Q
Naive B-cells in immunity
A
- 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
22
Q
During maturation in the thymus, T-cells undergo both
A
positive and negative selection
23
Q
positive selection
A
- allowing only the maturation of cells that can respond to the presentation of antigen on MHC
24
Q
negative selection
A
- causing apoptosis in cells that are self-reactive
25
thymosin
- 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
26
lymphokines
- helper t cells
- respond to antigens on MHC-II molecules
- recruit others
- loss of this is HIV
27
cytotoxic t cells
- directly killing virally infected cells by injecting chemicals promoting apoptosis
- T-cells respond to antigens presented on MHC-I molecules
28
suppressor T-cells
- can be differentiated from helper T-cells bc they also express Foxp3 to tone down immune response and prevent autoimmune disease
29
memory T-cells
- similar to memory B-cells
- lie in wait until the next exposure to the same antigen
- carry out robust and rapid response
30
bacterial infection
- 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
31
viral infection
- 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
32
self-antigen
protect cell from autoimmunity
33
hypersensitivity reactions
allergies and autoimmunity
34
why are glucocorticoids so efficient in treating autoimmune diseases?
they have immunosuppressive qualities
35
lymph join to form…
the thoracic duct
36
the thoracic duct delivers fluid to…
the left subclavian vein
37
lymph nodes contain…
a lymphatic channel, artery, and vein
38
lymph nodes function to…
provide a space for the cells of the immune system to be exposed to possible pathogens
39
edema
swelling due to fluid collecting in tissue
40
lacteals
- 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
41
germinal centers
collections of B-cells in lymph nodes to proliferate and mature
42
which cells produce antibodies?
plasma cells
MCAT Biology
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