IV9 - VI. Hemostasis (stoppage of blood flow after damage)...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Physiology of Blood IV. Platelets (thrombocytes - "clotting") A. General Characteristics 1. very small, 2-4 microns in diameter 2. approximately 250-500,000 per cubic millimeter 3. essential for clotting of damaged vasculature 4. thrombopoietin - regulates platelet production B. Formation of Platelets hemocytoblast-> myeloid stem cell-> megakaryoblast-> promegakaryocyte-> megakaryocyte-> (large multilobed nucleus) platelets (anucleated parts of megakaryocyte cytoplasm) V. Plasma (the liquid part of blood) A. General Characteristics 1. plasma makes up 55% of normal blood by volume 2. water is 90% of the plasma by volume 3. many different SOLUTES in the plasma a. b. c. d. other proteins - enzymes, hormones, others e. nutrients - glucose, fatty acids, amino acids, cholesterol, vitamins f. electrolytes - Na + , K + , Ca ++ , Mg ++ , Cl - , phosphate, sulfate, bicarbonate, others
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: VI. Hemostasis (stoppage of blood flow after damage) A. General Characteristics 1. vascular spasms (vasoconstriction at injured site) 2. platelet plug formation (plugging the hole) 3. coagulation (blood clotting - complex mechanism) B. Vascular Spasms 1. first response to vascular injury - VASOCONSTRICTION is stimulated by: a. compression of vessel by escaping blood Physiology of Blood b. injury "chemicals" released by injured cells c. reflexes from adjacent pain receptors C. Formation of a Platelet Plug 1. damage to endothelium of vessel 2. platelets become spiky and sticky in response 3. platelets attach to damaged vessel wall to plug it 4. platelets produce thromboxane A2 - granule release 5. serotonin release enhances vascular spasm 6. ADP - attracts and stimulates platelets at site 7. prostacylin - inhibits aggregation at other sites...
View Full Document

This note was uploaded on 01/29/2012 for the course SCIE SYG2000 taught by Professor Bernhardt during the Fall '10 term at Broward College.

Page1 / 2

IV9 - VI. Hemostasis (stoppage of blood flow after damage)...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online