Vascular and PLT Function Lecture 1

Question 1

Describe Hemostasis

Answer 1

blood clotting to arrest bleeding and re-establish blood flow during the healing process

Has a balance
Involves vascular, plts, coag cascade, control, fibrinolysis

Question 2

Primary Hemostasis Overview

Answer 2

Plt aggregation

WHITE THROMBUS

Question 3

Secondary Hemostasis Overview

Answer 3

Fibrin Strands

RED THROMBUS

Question 4

Hemathralgia

Answer 4

bleeding into joints

Question 5

Purpura
Ecchymoses

Answer 5

Bruises

Question 6

Epistaxis

Answer 6

nose bleed

Question 7

DVT

Answer 7

abnormal clotting in deep veins such as the legs

Question 8

Cryoprecipitate

Answer 8

substrate from human plasma can be transfused

Question 9

Stages of hemostasis
Primary

Answer 9

role of blood vessels/plts at site forming plt plug

Question 10

Vascular Parameter

Tunica Intama (Inner layer)

Answer 10

Broad flat enothelial cells

BM collagen

Prevents blood from reacting with other layers

Question 11

Stages of hemostasis
Secondary

Answer 11

fibrin developes to stregnthen plts

Question 12

Vascular Parameter

Tunica Media (middle)

Answer 12

elastic/smooth,

Constricts and dilates

Question 13

Vascular Parameter

Tunica Adventia (outer)

Answer 13

connective/support tissue

Question 14

Resistance to thrombosis formation
phy
p/n
synth by,
v
inhibits?

Answer 14

Physical barrier

Prostaglandin PG12/PG12 and Nitric Oxide

synth by endoth cells, vasodilator, inhibits plt adhesion

Question 15

More about Resistance to thrombosis formation
involved in activity of?
inhibits?

what inhibits tissue factor?

Answer 15

involved in activity of protein C and Anti-thrombin, both inhibit factors of the cascade

TFPI inhibits tissue factor

Question 16

When endothelial cells are disrupted
vaso…

Answer 16

Vasoconstriction - slows blood flow and sheer stress

Question 17

Initial stimuli of hemostasis

Answer 17

PAF, TF III, Collagen

Question 18

localize clot formation
what adhesion?
endo cells syth and release?

pts….secrete?

Answer 18

collagen plt adhesion

endo cells synth and release VON Williebrand Factor

(plts adhere, secretes ADAMS13, binding for IXA/XA)

Question 19

provide activators for clearance of thrombus

Answer 19

to break down fibrin clot TPA

Question 20

Endothelial cells play roles in both?

Answer 20

procoag and anticoag

Question 21

Hematopoesis in the BM

Answer 21

plts apart of myeloid cell lines from HSC

Megakaryocyte —plt

Question 22

TPO/ Thrombopoetin

Answer 22

regulates megakary production and plt release from BM in response to thrombocytopenia

Binds to receptors on plts

Inhibits megakary apoptosis

Increased Plts = DECREASE TPO = few megakaryocytes

Question 23

Ultrastructure of plts

Peripheral Zone

Glycocalyx
mediates?

Answer 23

mediates plt adhesion and aggregation

(adhesion) plts stick to blood vessel

Aggreg - plt stick to plt

Question 24

Ultrastructure of plts

Peripheral Zone

Open canalicular system

Answer 24

extension of plt membrane, winds down to interrior

Question 25

Sol-Gel Zone of plts Cytoskeleton facilitates? micro/cont

Answer 25

maintains shape, facilitates secretion process microfilaments and contracticle proteins

Question 26

Sol-Gel Zone of plts Dense tubular system

Answer 26

plt activation and Ca++ storage

Question 27

Organelle Zone of PLTS Lysozomes/Mitochonrdria

Answer 27

lYSO - few, may disrupt endo structure after vasc. Mito - ATP synth

Question 28

Organelle Zone of Plts Granules

Answer 28

Dense granules (ADP/CA++/Serotonin) larger and fewer in numbers Alpha Granules (TXA2,VWF,FV,FVIII,FI,HMWK,PF4) more numerous

Question 29

Thromboxane A2

Answer 29

plt activation and aggregation ASPRIN inhibits cyclooxinganase and inhibits plt activation and aggregation

Question 30

Plt function in vascular injury Adhesion sticking to what is glue? platelet receptor for VWF? what does vwf carry?

Answer 30

sticking to collagen collagen exposed VWF is glue between collagen and plts (plt receptor for VWF is GP IB) VWF carries FVII

Question 31

Plt function in vascular injury Activation shape...causes? stim by agonists....what is formed from the plt? Receptors?

Answer 31

initiated by plt adhesion induces a shape change which allows release of granules/secretion stim by agonist - pseudopods w actin and myosin, glycoprot IIB/IIIA receptors

Question 32

Plt function in vascular injury Release reaction/secretion S V A T C F

Answer 32

plt adhere and are stim to secrete contents of granules Serotonin: vasocontriction VWF: plt adhesion ADP plt aggregation TXA2 plt aggregation Ca: activates plts/cascade Fibrinogen: plt aggregation/cascade

Question 33

Plt function in vascular injury Agreggation what exposes GP IIB/IIIA complex? recruits? what attaches and makes a bridge? this causes?

Answer 33

ADP and TXA2 expose GP IIB/ IIIa complex recruit more plts to site fibrinogen attaches to plt membrane forming bridge, results in PLUG

Question 34

Plt function in vascular injury Clot retraction

Answer 34

actin and myosin contract, pulls everything back in stopping bleeding

Question 35

PLT plug

Answer 35

provides foundation for clot form such as phospholipid PF3 (plt factor 3) "not a true facotr" supports coag cascade provides binding for vit K

Question 36

Plt effectiveness very young what reverses activation of plts

Answer 36

more dependent on function than # <50 x 103 may have prob w surgery <10 x 103 spontaneous bleeds very young plts may posses increased activity PG12 reverses activation of plts