Primary homeostatsis Day 2

What is the largest hematopoietic cell in the bone marrow

megakaryocyte

how many platelets does the megakaryocytic shed

1000-3000

Thrombopoietin is produced by

• liver

• kidney

• spleen

adult reference range for plts

150-400k

alpha granules produce

• PF4

• Bets thromboglobulin

• plt derived growth factor

PF4

neutralizes heparin

Beta thromboglobulin

attracts fibroblasts and neutralizes heparin

plt derived growth factor

wound repair

Dense bodies contain

non-metabolic ADP/ATP

What do dense bodies release during plt aggregation

1. ADP/ATP

2. Calcium

3. Mg

4. Serotonin

membranous zone

Surface connected open canicular system within platelets for secretion.

Dense tubular system

A network of tubules found in platelets, involved in calcium storage and release during activation.

Surface connecting system

that facilitates secretion in platelets.

membranous zone contains

• surface connecting system

• dense tubular system

stages of plt plug formation

1. plt adhesion

2. plt activation

   • plt contraction/shape change

   • granule secretion/plt contraction

3. plt aggregation

injured epithelium releases

1. plt activating factor, serotonin, and thromboxane A2 causing vasoconstriction

2. tissue thromboplastin

3. vonwillebrands factor

4. plasminogen activator inhibitors

plt adhesion requires

• glycoprotein IB

• von willebrands factor

agonists that shape a plt are

• ADP

• Plt activating factor

• Serotonin

• Thromboxane A2

What are the non plt derived agonists

• collagen

• thrombin

• epinephrine

in primary aggregation weak stimuli is only…

alpha granules that release PF4 and vWF

in primary aggregation the strong stimuli are…

• ADP, calcium and serotonin from dense bodies

Secondary aggregation includes

• GPIIb/IIIa

• fibrinogen cross-linking of platelets.

Plt plug stabilization includes

PF3

fibrin formation is part of…

secondary homeostasis

PF3

fluffy surface phospholipid layer that becomes the site for coag factors to complete their action

PF4

a substance released from the alpha granules that will neutralize heparin

the anitplt drugs that prevent plt adehesion act by binding to…

GPIIb/IIIa

Plavix blocks what site

P2Y12ADP receptor on plts

Aspirin irreversibly inhibits…

cyclooxygenase

in the process f plt plug formation arachidonic works with cyclooxygenase and thromboxane synthase to convert it into…

Thromboxane A2

clinical symptoms of a primary homeostasis bleeding disorder are…

• petechia

• ecchymosis

• hematoma

• purpura

• cardiovascular accidents

what are 4 genetic vascular diseases

• hemangiomas and telangiectasis

• osteogenesis imperfecta

• marfans syndrome

• Ehlers Danlos

hemangiomas and telangiectasis includes what defect

increased dilation of capillaries with thin walls

osteogenesis imperfecta includes what defect

collagen disease, patchy defective bone matrix

marafans syndrme includes what defect

collagen disease, decreased elasticity of vessels

Ehlers danlos includes what defect

collagen disease, increased fragility of vessels leading to hyper flexability

idiopathic or immune thrombocytopenic purpura is caused by

autoantibodies directed against plts

Non immune mechanisms of destruction of plts include…

• DIC

• HUS

• TTP

• snake bites/viral toxins

• direct physical destuction

Disseminated intravascular cagulation test results would abnormal…

PT, PTT, and D-dimer

HUS tests would have normal…

PT/PTT

TTP would normally have normal tests…

PT, PTT, D-dimer

prolonged bleeding time can indicate…

plt function disorders

uremia or drug induced plt defects

thrombocytopenia

PFA 100 analyzer replaces

bleeding time

What are commonly used agonists in testing…

• ADP (r/o storage pool)

• Epinephrine (r/o storage pool disorders)

• Thrombin (strong agonist+ ibrin clot formation)

• Ristocetin (reduces repelling charge)

• Arachidonic acid (r/o aspirin)

Bernard Soulier mechanism

lack GP Ib/IX binding site on plt

Glanzmann thromboasthenia mechanism

lack GPIIb-IIIa

ADP release is quantified by

light emittance using luciferin luciferase

Whole blood method of plt aggregation testing is tested using

electrodes