Hemostatic Systems

Question 1

what is a hemostatic system

Answer 1

a balance between procoagulant and anticoagulant forces maintains blood in fluid state and flowing through the vasculature to deliver oxygen to tissues systematically and remove CO2 and toxic waste products

Question 2

what are the 3 main stages of the hemostatic system

Answer 2

-vasoconstriction of blood vessels
- formation of a platelet plug with collagen fibers
- blood clotting which reinforces the platelet plug with a fibrin mesh

Question 3

what are the 2 homeostatic pathways when BP and blood volume decrease

Answer 3

endocrine mechanism and neural mechanism

Question 4

what is the endocrine mechanism of homeostasis

Answer 4

ADH, angiotensin II, aldosterone, EPO are released which increases blood volume

Question 5

what is the neural mechanism of homeostasis

Answer 5

baroreceptors and chemoreceptors stimulated, cardiovascular centers stimulated, sympathetic activation, release of norepinephrine and epinephrine. this increases CO and BP

Question 6

what do sympathetic nerves trigger

Answer 6

contraction of smooth muscle in vessels

Question 7

what does serotonin do

Answer 7

vasoconstricts in high concentrations. indirectly can act as a vasodilator when it stimulate NO release by cells

Question 8

what synthesizes serotonin

Answer 8

platelets at NMJs

Question 9

what makes and releases endothelin-1

Answer 9

damaged endothelial cells

Question 10

what can happen if endothelin-1 is overexpressed

Answer 10

high BP, heart disease, lung kidney and brain disease

Question 11

what does histamine bind to

Answer 11

histamine GPCRs on GI, uterus, lung, vascular SM cells

Question 12

what does histamine do

Answer 12

vasodilation of vasculature and vasoconstriction of airways

Question 13

what produces and released histamine

Answer 13

basophils in circulation and mast cells in tissue

Question 14

what does prostacylin (PGI2) do

Answer 14

inhibits platelet activation and is a vasodilator

Question 15

what does PGI2 counteract

Answer 15

TXA2

Question 16

what is the mechanism of action of PGI2

Answer 16

binds to PGI2 receptor (GPCR) which signals adneylyl cyclase to produce cAMP which activates PKA which leads to vascular smooth muscle relaxation and vasodilation

Question 17

what is thromboxane A2 made and released by

Answer 17

platelets and endothelial cells

Question 18

what is TXA2

Answer 18

a prostaglandin

Question 19

what doeos TXA2 do

Answer 19

stimulates activation of new platelets and increases platelet aggregation by increasing expression of GPIIb/IIIa (fibrinogen receptor) on platelet membranes

Question 20

what do PGI2 and TXA2 have in common

Answer 20

they both have a short half life and are potent acting locally not systemically

Question 21

what are the intrinsic factors of vascular tone

Answer 21

myogenic, endothelial, local substances, and metabolic byproducts

Question 22

what are the extrinsic factors of vascular tone

Answer 22

sympathetic nerves and circulating factors

Question 23

how do constrictor influences affect vascular tone

Answer 23

increase vascular tone

Question 24

how do dilator influences affect vascular tone

Answer 24

decrease vascular tone

Question 25

what do myogenic mechansims do

Answer 25

arise from vascular smooth muscle and constrict vessels, increasing tone

Question 26

what are endothelial factors

Answer 26

nitric oxide (vasodilator) and endothelin (vasoconstrict- increase tone)

Question 27

what are local factors

Answer 27

arachidonic acid metabolites, histamine, bradykinin (vasodilator or vasoconstriction)

Question 28

what do metabolic byproducts or hypoxia do

Answer 28

decrease tone (vasodilation)

Question 29

what does angiotensin II do

Answer 29

increase vascular tone

Question 30

what does ANP do

Answer 30

vasodilation- decrease tone

Question 31

what does ischemia do (pathway)

Answer 31

activate phospholipase A2 which cleaves arachidonic acid from phospholipids and uses COX1 and COX 2 to form prostaglandins

Question 32

what can a pluripotenital hematopoietic stem cell differentiate into

Answer 32

a lymphoid cell or myeloid cell

Question 33

what does the common lymphoid progenitor differentiate into

Answer 33

B cell, T cell and NK cell which mature into plasma cell, activated T cell and activated NK cell

Question 34

what does the common myeloid progenitor differentiate into

Answer 34

granulocyte/macrophage progenitor or megakaryocyte/erythrocyte progenitor

Question 35

what does the granulocyte/macrophage progenitor differentiate into

Answer 35

neutrophil, eosinophil, basophil,precursor of mast cell, monocyte. in tissues the mast cell matures and the monocyte becomes a macrophage

Question 36

what does the megakaryocyte/erythrocyte progenitor differentiate into

Answer 36

megakaryocyte or erythroblast

Question 37

what does the megakaryocyte differentiate into

Answer 37

platelets

Question 38

what does the erythroblast differentiate into

Answer 38

erythrocyte

Question 39

what do macrophages do

Answer 39

phagocytosis and bacteria kill and antigen presentation

Question 40

what do neutrophils do

Answer 40

phagocytosis and activation of bactericidal mechanisms, important in innate immune response

Question 41

what are the primary cells recruited to the site of acute inflammation

Answer 41

neutrophils

Question 42

what do mast cells do

Answer 42

release granules containing histamine and active agents

Question 43

how does histamine work

Answer 43

causes vasodilation and permits entry of cells and proteins into site of infection to engage invading pathogens. also a mediator of itching

Question 44

what happens in each of the 3 stages in erythropoiesis

Answer 44

1- ribosome synthesis 2- hemoglobin accumulation 3- ejection of nucleus

Question 45

what are the sites of hematopoiesis in fetus

Answer 45

first trimester-yolk sac second trimester- liver and spleen third- bone marrow

Question 46

what are platelets

Answer 46

anuclear membrane limited bags filled with granules and vesicles from megakaryocytes

Question 47

what is in the dense granules of platelets

Answer 47

-epinephrine - histamine - serotonin - Ca2+ ions - ADP - PDGF

Question 48

what happens when platelets are activated

Answer 48

forms temporary plug to seal breaks in vessels

Question 49

what are the 5 cardinal signs of inflammation

Answer 49

pain, heat, redness, swelling, loss of function

Question 50

what are the 3 major componenets to acute inflammation

Answer 50

- vascular changes - increased blood flow and vascular permeability - cellular events - migration of leukocytes into the site of injury - mediators - derived from plasma cells and proteins

Question 51

what are the temporal events of self-limited acute inflammation

Answer 51

edema -> PMN -> monocytes/macrophages -> tissue repair and regeneration

Question 52

when does the inflammation stage of healing occur

Answer 52

48 hour post injury

Question 53

when does the proliferation stage of healing occur

Answer 53

3-10 days post injury

Question 54

when does the remodeling stage of healing occur

Answer 54

21 days post injury

Question 55

what is exudate

Answer 55

high protein ( >1.02) - fluid and protein leakage, increased interendothelial spaces

Question 56

what is transudate

Answer 56

low protein (<1.01) - increased hydrostatic pressure - decreased colloid osmotic pressure

Question 57

what is pus

Answer 57

enriched in neutrophils

Question 58

what counteracts hydrostatic pressure

Answer 58

colloid osmotic pressure

Question 59

what is a type 1 inflammation and hypersensitivity disease and examples

Answer 59

anaphylactic, allergy ex: hayfever, bee sting, asthma, penicillin

Question 60

what is a type 2 inflammation and hypersensitivity disease and what happens

Answer 60

antibody dependent - cell membrane is altered to non self ex: graves disease

Question 61

what is a type 3 inflammation and hypersensitivity disease

Answer 61

immune complex type - involves antibody-antigen complex cause tissue damage

Question 62

what is a type 4 inflammation and hypersensitivity disease

Answer 62

cell mediated ( delayed type hypersensitivty) - protect against intracellular pathogens - mediated by T-cells ex: poison ivy