Access Millions of academic & study documents

03 platelets

Content type
User Generated
Showing Page:
1/16

Sign up to view the full document!

lock_open Sign Up
Showing Page:
2/16

Sign up to view the full document!

lock_open Sign Up
Showing Page:
3/16

Sign up to view the full document!

lock_open Sign Up
Showing Page:
4/16

Sign up to view the full document!

lock_open Sign Up
End of Preview - Want to read all 16 pages?
Access Now
Unformatted Attachment Preview
PLATELETS THROMBOCYTES • • • • • Small, non nucleated, granulated. 2-4μm in diameter. Count: 300.000/mm3. Life span: 8 days. Platelets are important in hemostasis. • There are two types of granules: – Dense granules: contain non protein ADP; serotonin and Ca2+. ‫التحتوي‬ substances; – Alpha granules: contain protein substances ‫تحتوي‬ Hemostasis Definition: it is stoppage of bleeding injured blood vessels. ‫ايقاف النزيف‬ Injury of blood vessel Hemostasis Platelet plug formation Local vasoconstriction reduces blood flow Blood clotting formation of fibrin threads Mechanical sealing at site of injury through platelet reactions • Adhesion • Activation • Release ‫استدعاء‬ • Aggregation • Irreversible fusion • Procoagulant activity from 1. Hemostasis is carried out by three mechanisms: Local vasoconstriction of cut blood vessel which reduces the blood loss ‫تقلل بس‬ • This is done by the following mechanisms a) Local myogenic contraction caused by direct damage. It is proporational to degree of damage. b) Nervous reflex: • Occurs in response to pain and causes vasoconstriction of cut blood vessel. C) Release of chemical substances as thromboxane A2 and ADP from platelets that cause serotonin, vasoconstriction. ‫قال عامر كله بيعمل‬ Vasoconistriction BLOOD CLOTTING (COAGULATION) • It is the process of formation of fibrin threads from fibrinogen whic ...
Purchase document to see full attachment
User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.
Studypool
4.7
Indeed
4.5
Sitejabber
4.4