Primary Hemostasis

Primary Hemostasis

initial plug of injury by response of platelets and vessel walls

Glycocalyx

the exterior coat of the platelet

Adhesion

the platelet binding to the disrupted endothelium

Aggregation

platelet binding to platelet

Platelets: three zones

peripheral, sol-gel, and organelle

Peripheral Zone

platelet membrane & glycocalyx

• stimulus receptor and transmitter region

• surface for coagulation

• adhesion

Sol-Gel Zone

• platelet muscle

• shape change

• clot retraction

Organelle Zone

Secretion

Grey Platelet Syndrome

deficiency of alpha granules

Storage Pool Disease

deficiency of dense bodies

Dense bodies

contain ADP, ATP, calcium, and serotonin

Reference range for platelets

150,000-450,000/cumm

Platelet Activation Process

1. adhesion

2. shape change

3. aggregation

4. release or secretion

5. coagulation on platelet surface

6. clot retraction