General Path.

Question 1

antigen surveillance

Answer 1

T cells use TCR complex
CD4 - MHC II
CD8 - MHC I

Question 2

signals for cd4 activation

Answer 2

> antigen presented with MHCclass ii
> B7 on APC binds CD28 on CD4Tcell

Question 3

cd4 can help two cells

Answer 3

B cells, CD8

Question 4

th1 subset secretes ____ during NFL;

what is the effect?

Answer 4

IFN gamma; 
> activates macrophage
> promotes formation of Th1
> inhibits formation of Th2
IL2;
> Tcell GF 
> CD8 activator

Question 5

th2 subset secretes ____ during NFL;

what is the effect?

Answer 5

> IL4; class switch from igG to E
> IL5; eosinophil chemotaxis/activation, Bcells => plasma & class switching to IgA
> IL10; inhibits Th1 phenotype

Question 6

cd8 cytotoxic is activated with

Answer 6

> Ag presented on MHC I

> IL2 from cd4

Question 7

what do cytotoxic t cells secrete?

Answer 7

perforins
granzyme
Fas ligand

Question 8

B lymphocytes activated by

Answer 8

> Ag presented on MHC class II
> CD40 on B cell to CD40L on helper T cell

Question 9

epitheliod histiocyte

Answer 9

> macrophage with abundant pink cytoplasm
UZE surrounded by giant cells and rim of lymphocytes
this is the defining feature of a granuloma

Question 10

non caseating granulomas

Answer 10

> lack central necrosis

> from rxn to foreign material

Question 11

caseating granulomas

Answer 11

> exhibit central necrosis

> characteristic in TB and fungal infections

Question 12

differential for non caseating granulomas

Answer 12

> Chron’s
sarcoidosis
beryllium
cat scratch disease

Question 13

what macrophage cytokine stimulates formation of Th1 helper T cells

Answer 13

IL-12; this happens in both caseating and non caseating granulomas

Question 14

what Th1 cytokine stimulates formation of epitheliod histiocytes and giant cells?

Answer 14

IFN gamma

Question 15

what are the key mediators in apoptosis

Answer 15

caspases

Question 16

leukocyte MARGINATION

Answer 16

> step 1
vasodilation slows blood in POST CAP. VENULES
cells marginate from center to the PERIPHERY

Question 17

leukocyte ROLLING

Answer 17

> step 2
histamine triggers Pselectin from WEIBEL PALADE bodies
Eselectin induced by TNF & IL1
selectins on endothelial

Question 18

leukocyte ADHESION

Answer 18

> step 3
ICAM/VCAM on endothelium (TNF, IL1 trigger)
Integrins on leukocytes (C5a, LTB4 triggered)
interaction btn CAMs and integrins is FIRM

Question 19

leukocute TRANSMIGRATION, CHEMOTAXIS

Answer 19

> step 4
> neutrophils attracted via
>>> bacterial products
>>> IL8
>>> C5a
>>> LTB4

Question 20

leukocyte PHAGOCYTOSIS

Answer 20

> step 5
enhanced by opsonins.
» IgG
» C5b

Question 21

leukocyte WASTE REMOVAL

Answer 21

> step 6
O2 is the most effective mechanism
HOCl is generated during oxidative burst and kills microbes

Question 22

oxidative burst enzymes

Answer 22

O2 => O2- => H2O2 => HOCl

1) NADPH oxidase
2) superoxide dismutase
3) myeloperoxidase

Question 23

What does elevated D-dimer mean? why?

Answer 23

> abnormal thrombotic states (DIC, DVT, pulm. embol.)
D-mers are are a type of FIBRIN SPLIT PRODUCT
fibrin split products occur from degrading fibrin clots

Question 24

Virchows triad

Answer 24

> hypercoaguloability
abmornal blood flow
endothelial injury

Question 25

clinical conditions of hypercoagulobility

Answer 25

factor V leiden and prothrombin gene mutations | many others too, but these are common inherited

Question 26

clinical conditions of abmornal blood flow

Answer 26

> turbulence from athrerosclerotic plaques > stasis from sickle cell anemia vascular occlusions > hyperviscosity from polycythemia vera

Question 27

clinical conditions of endothelial injury

Answer 27

> vasculitis > trauma, inflammation > hypertension

Question 28

warfarin inhibits

Answer 28

> inhibits all of the calcium dependant clotting factors | > 2, 7, 9, 10, protein C, protein S

Question 29

heparin acts on

Answer 29

> anti-thrombin III to accentuate/catalyze inhibition of factor 10a and 9 a.

Question 30

both heparin and warfarin act on both sides of the coagulation cascade (T/F) Significance in labs?

Answer 30

true. they both increase PT/INR and PTT

Question 31

which test is most sensitive for coumadin?

Answer 31

coumadin is most sensitive to PT/INR testing

Question 32

which test is most sensitive for heparin?

Answer 32

heparinis most sensitive to PTT testing

Question 33

relationship between warfarin and coumadin

Answer 33

they are the same. "Coumadin" is the brand name for the active ingrediant warfarin sulfate

Question 34

streptokinase is?

Answer 34

> bacterial enzyme | > it cleaves plasminogen to plasmin => FIBRINOLYSIS of fibrinclot

Question 35

lymphadenitis vs lymphangitis | clinical features

Answer 35

> angitis appears as a red, subQ streak | > adenitis is enlargement of the nodes