HDM Midterm Flashcards
Which type of immunity has no memory and responds the same way to every pathogen every time it infects? What are the main effector cells in this type of immunity?
Innate (natural)
Phagocytic cells, NK cells, Complement
Which type of immunity has memory and responds the faster upon subsequent infections? What are the main effector cells in this type of immunity?
Acquired (adaptive)
B cells, T cells
Which type of immunity is considered the first line of defense?
Innate
Rapid, causes inflammation, low specificity, no memory: these are all descriptive of which line of immunity?
Innate
Develops slowly, high specificity, memory: these are all descriptive of which line of immunity?
Adaptive
What are the components of inflammation?
Hot, red, swollen, pain, loss of function
Describe what happens when bacteria invades skin surface causing inflammation.
Surface wound, bacteria enters, resident cells secrete cytokines, vasodilation, increased vascular permeability, inflammatory cells leave blood entering tissue, tissue becomes inflamed
Skin, mucous membrane, temperature, acidic pH, and lactic acid are all examples of which component of the innate immune system?
Physical barriers
Which effector cell provides defense against helminths?
Eosinophil
What do immune cells look For to distinguish between Self and non self?
pathogen associated molecular patterns (PAMPs) are recognized by pattern recognition receptors (PRRs)
What are examples of some bacterial PAMPs?
LPS, techoic acid, peptidoglycan, mannose proteins
Which toll-like receptor activates inflammation in the presence of Gram positive bacteria
TLR2- recognizes peptidoglycan
Which toll-like receptor activates inflammation in the presence of gram negative bacteria
TLR4- recognizes LPS
TLR1:TLR2 is a heterodimer cell receptor found on monocytes, mast cells, DCs, eosinophils and basophils that recognizes what kind of PAMP?
Lipopeptides on bacteria, GPI on parasites
TLR2:TLR6 is a heterodimer found on monocytes, DCs, mast cells, eosinophils, and basophils that recognizes what PAMPs?
Lipotechoic acid (gram + bact) and yeast
Which TLRs are found intracellular in the endosomes?
3, 7, 8, 9
TLR3 on NK cells detects what kind of PAMP?
Double stranded viral RNA
TLR4 on macrophage, DC, mast cells, and eosinophils that detects what PAMPs?
LPS on gram - bacteria
TLR5 on intestinal epithelium recognize what PAMPs?
Flagellin (bacterial)
TLR7 on DCs, NK cells, eosinophils, B cells recognizes what PAMPs?
Single stranded viral RNA
TLR8 found on NK cells recognizes what kind of PAMPs?
Single stranded viral RNA
TLR9 on DCs, B cells, eosinophils, and basophils recognize what kind of PAMPs?
Unmethylated CpG-rich DNA
Which TLRs recognize Bacterial lipopeptides?
2, 6
Which TLRs recognize bacterial flagellin
5
Which TLRs recognize LPS
4
Which TLRs recognize peptidoglycan
2
Which TLRs recognize lipopeptides
1, 2
Which TLRs recognize dsRNA
3
Which TLRs recognize ssRNA
7, 8
Which TLRs recognize CpG DNA
9
Term for small proteins. Secreted. By. Cells to mediate inflammation, immunity and hematopoiesis
Cytokines
Small fragmetns of the complement serve what purpose
Opsonins, chemotactic factors, anaphylatoxins
Which complement cascade begins with Ag-Ab complexes?
Classic
Which complement cascade pathway begins with microbial carbs binding mannose binding protein?
Lectin
what is the difference between thick and thin skin? Where do you find thick skin?
keratin in the outer layer (thick skin only), no sweat glands or hair in thick skin, only thick skin has stratum lucidum
palms and soles of feet
these cells are more numerous in thick skin (stratum basal), they have free nerve endings, they come from neural crest cells and act as mechanoreceptors
merkel cells
how can you tell the difference between melanocyte and merkel cell? (both found in stratum basal)
merkel- larger cell with more well defined nucleus
loose connective tissue makes up the dermis. what are dermal projections called?
dermal papillae and epidermal ridges
the ___ has a rich blood supply whereas the ___ does not (layers of integument)
dermis, epidermis
what are dermatoglyphics?
fingerprints
what are the 2 layers of dermis
papillary and reticular layer
the dermis is rich in what
elastic fibers
which layer of the integumentary system contains capillary loops
dermis
these are found in the papillary layer of the dermis and their function is to act as encapsulated touch receptor
meissners corpuscles
where in the body do we find meissners corpuscles?
lips, finger tips, plantar feet, genitals
what type of tissue and fiber are found in the reticular dermal layer of skin?
dense irregular CT, collagen (type I) and some elastic
what provides thermoregulation in the dermis?
arteriovenous anastomoses
how can you distinguish between meissner and pacinian corpuscle?
meissners- in papillary layer
pacinian- in reticular layer and bigger
what component of the dermis is responsible for sensing stretch
ruff ini end organ
this nerve ending is wrapped around base of a hair follicle
peritrichial
although this structure buds from hypodermal layers, it is of epidermal origin
hair
this integumentary layer contains adipose tissue and subcutaneous fascia
hypodermis
what are the 3 components of hair shaft
cuticle, cortex, medulla
what muscles are responsible for giving us goose bumps?
arrector pili muscles (associated with the hair shaft)
what two layers surrounding a hair follicle are only present in the dermis and not in the portion of hair that sticks up out of the skin?
internal and external root sheath
what are the two types of glands associated with skin?
sweat and sebaceous
what type of exocrine secretion involves secretory product that remains entirely in the lumen of the gland before secretion?
merocrine
what type of exocrine secretion involves portions of secretory glands pinching off to release secretory products?
apocrine
what type of exocrine secretion involves entire cells including secretory product budding as new cells form
holocrine
sweat glands are all what shape? they are what type of secreting gland?
coiled, some are merocrine(eccrine) and some are apocrine
sebacious glands are what shape? What secretory mechanism do they use to release product?
branched alveolar, holocrine secretion
hair always includes what type of gland
sebacious
whats the most abundant type of sweat gland? what are the components of this watery secretory product?
eccrine (merocrine)
made of water, salt, ammonia, uric acid, mucinogen granules
where on the body do you find apocrine sweat glands?
axilla, pubic, anal, areola, external genitalia
what causes the odor associated with apocrine sweat gland secretion?
bacterial breakdown
what type of glands produce ceramic in the outer ear?
apocrine sweat glands
what type of gland is associated with eye lids and eye lashes
ciliary glands of Moll (apocrine sweat glands)
what is responsible for expelling secretions from glands?
myoepithelial cells
the secretory portion of a gland is surrounded by what type of tissue
simple cuboidal epithelium
the duct portion of a gland is surrounded by what type of tissue
stratefied cuboidal epithelium
describe finger and toe nails histologically
keratinized plates of cells on a bed of epidermis
nails are analogous to but much harder than what layer of the epidermis
stratum corneum
what is the term describing small white area near the proximal nail plate (beneath the nail matrix)
lunula
scientific term for cuticle
eponychium
fold of stratum corneum at the proximal end of the nail plate is called what? at the distal edge?
proximal- eponychium (cuticle)
distal- hyponychium
which type of sweat gland is most responsible for thermoregulation?
eccrine
macrophages and dendritic cells express what class of MHC molecules?
both I and II
B cells express what class of MHC molecules?
both I and I
erythrocytes express what class of MHC molecules?
none
which cells express class I MHC molecules?
all nucleated cells
what are the 2 primary lymphoid organs that produce cellular components of the immune system
bone marrow, thymus
what are secondary lymph organs?
where immune responses occur (lymph nodes, spleen, tonsils)
The thymus is a lymphoid organ possessed two lobes separated by a septa and a CT capsule. the medulla stains lighter and contains __ corpuscles
hassals
does the thymus contain lymphoid nodules? Germinal centers?
no and no
T cells mature in the thymus as they travel in what direction?
from cortex to medulla
other than T cells what immune cells are present in the thymus?
macrophages in both cortex and medulla
DC’s in medulla
these cells are found in thymic medulla. they are tightly packed epithelial cell that signal for thymic DC’s to complete T cell maturation
hassals corpuscles
epithelial reticular cells are bound to capillaries in the thymic cortex to protect developing T cells from what
circulating antigens (no direct blood supply to the medulla)
what is the job of a macrophage in the spleen
RBC breakdown
this organ traps antigens, serves as a platelet reservoir and completes hematopoiesis
spleen (no cortex or medulla)
is the spleen capsulated? if so what makes up the capsule?
yup, collagen, elastic fiber, smooth muscle
what divides the spleen into compartments?
trabeculae
reticular fibers make up the parenchyma of the spleen and support what two subunits
red and white pulp
this portion of spleen is rich in lymphoid tissue
white pulp
this portion of spleen is rich in RBCs
red pulp
list the components of white pulp of the spleen
germinal center, corona, central artery, periarteriolar lymphoid sheath
what is present in the corona of white pulp in the spleen
b cells and APCs
where are t cells found within white pulp of the spleen
periarteriolar lymphoid sheath
what are the components of red pulp in the spleen
splenic cord (reticular cells), splenic sinusoid, pennicillar arteries, macrophage sheathed cappilary, circulating blood cells
describe blood flow to / through the spleen
celiac trunk –> splenic artery–> trabecular aa.–> through trabeculae–> parenchyma of spleen–> central aa.–> penetrate white pulp (surrounded by periarteriolar lymph sheaths)–> radial aa.–> marginal zone sinuses
central–> red pulp via penicillar arteries–> splenic sinusoids (closed) OR into red pulp (open)
penicillar aa. are surrounded by what
macrophages that remove damaged RBCs
what is the smallest lymphoid organ
lymph nodes
are lymph nodes encapsulated? do they contain trabecular?
yes and yes, they have cortex and medulla
term describing the spot where arteries and veins and efferent lymph vessels enter the lymph node
hilum
where in the lymph do T cells predominate? B cells?
inner cortex, outer cortex
lymphatic nodules are present within this T cell rich region of a lymph node
inner cortex
spaces within lymph node lined with endothelial cells surrounded by reticular cells and macrophages
medullary sinuses
medullary sinuses in lymph nodes are a mesh of reticular cells and fibers that filter lymph and direct its flow. How are antigens removed from lymph in these spaces?
macrophages and follicular DCs
which lymphoid organ does not contain lymphoid nodules
thymus
which lymphoid organ(s) contain cords and sinuses
nodes and spleen
which lymphoid organ(s) contain cortex and medulla
thymus, nodes
which lymphoid organ(s) contain hassles corpuscles
thymus
which lymphoid organ(s) contain central arteries
spleen
which lymphoid organ(s) contain epithelial covering
tonsils
which lymphoid organ(s) contain cortical nodules with sub capsular sinuses
nodes
Who do APC’s present antigens to?
T cells
Who presents Ag’s to naive T cells?
DC’s
HLA genes are highly pleomorphic and have what type of expression?
Codominant
MHC I molecules. Have a small grove. For binding protein fragments. What are the 3 human MHC I genes? What protein do each of these bind on the cell surface?
HLA-A
HLA-B
HLA-C
Beta-2 Microglobulin
What is the major barrier to transplants?
MHC I (because it is expressed on alllll of our cells)
Which segment of a MHC I molecule is recognized by the CD8 T cell during Ag presentation?
CDR (complementary determining region) of the TCR
MHC I. Molecules sample all of what within a. Cell?
Proteins being made (self or nonself that is the question)
What stabilizes the interaction between CD4 and MHCII?
CD4 recognizes conserved regions of MHCII
What sits in the groove of MHC II to keep peptides from binding here in the ER?
Invariant chain
What protein is required to remove CLIP from MHC II so that Ag peptide can bind here?
HLA-DM
What is the source of protein Ag for MHC I ? How about for MHC II ?
I- Cytosol
II- Endosomal/ lysosomal
What is responsible for peptide fragment generation for display by MHC I? II?
I- proteosome
II- phagolysosomal proteases
Where does MHC get loaded for class I? Class II?
I- ER
II- vesicular compartment
What proteins are required to get peptide fragments into the ER for presentation by MHC I?
TAP
Professional APCs can process what type of antigen for presentation via MHC I during cross presentation?
Exogenous
Antigens that can be cross presented always enter the cell via what mechanism?
endocytosis (MHC II pathway because they are exogenous proteins)
Cross presentation can be used by all professional APCs but it is mostly used by which type of cell?
DC’s
Why must we. Use cross presentation?
Virally infected cells die and their debris must be picked up from the EXOGENOUS environment and then that cell must be killed via CD8 T cell killing so that the virus does not continue to spread
A surface Ig (IgM. Or IgD) together with what two peptides makes up the BCR
Ig alpha & Ig beta
TCR includes what two chains that are disulphide linked Extracellularly? What chains are present intracellularly?
Alpha and beta chains, intracellular= 2 zeta chains
The TCR complex includes an alpha subunit, a beta subunit, two zeta chains and what other molecule?
2 CD3 molecules
This subset of T cells is few in number (mostly found in epithelium) but is able to recognize PAMPS without an APC.
Gamma/ delta (no memory)
Rather. Than. In plasma, where are most plasma cells. Found?
Lymphoid organs
What costimulatory molecules are necessary in order to activate a T cell?
CD 80/86 (B7) which binds CD 28 on t cells
