1. Cardiovascular System: Blood

2. General Properties of Blood
Volume in adult body
Female = 4 -5 liters
Male = 5 – 6 liters
pH = 7.35 to 7.45
Temp = 38 oC
100.4 oF

4. Hematocrit Hematocrit = percent volume of whole blood occupied by RBC

5. p 681

7. Erythrocytes or Red Blood Cells
No nucleus
Life span = about 120 days
Average Count
Male = 5.4 million / mm3 (μL)
Female = 4.8 million / mm3 (μL)
Production called erythropoiesis
Takes about 4 days
Rate = 2 to 3 million per second !
p 687

8. Erythrocytes on the tip of a hypodermic needle

9. Hemoglobin Globin = one of four protein chains
Heme = one of four nonprotein parts with an Fe++ at their center that binds with O2 for transport
About 280 million hemoglobin molecules per RBC
p 686

10. What kind of feedback system?
p 688

11. On average about 26 mg of Fe+2 is used to make new hemoglobin per day
Recycling Iron
On average about 26 mg of Fe+2 is used to make new hemoglobin per day
Body only requires about 1-2 mg per day from diet to replace Fe+2 lost in kidney & GI tract
p 689

12. Amino Acids from globin proteins
Hemoglobin Recycling
Iron
Amino Acids from globin proteins
p 689

14. Leukocytes or White Blood Cells
5,000 to 10,000 / mm3 (μL)
Compared to about 5 million for RBC
Granulocytes
Eosinophils
Basophils
Neutrophils
Agranulocytes
Monocytes
Lymphocytes

15. Protection against foreign invaders in body
Neutrophils – phagocytosis
Eosinophils – phagocytosis
Basophils – release histamine & heparin
Lymphocytes – produce immune response to remove foreign antigens
Monocytes – differentiate into macrophages
(large phagocytes)
p 698-9

16. Platelets (Thrombocytes)
Not really cells, but fragments of a larger cell called a megakaryocyte
Average 250,000 / mm3 (μL)
Play a major role in hemostasis or stopping bleeding
p 703

17. Hemostasis
p 704

18. Vascular Spasm
Vascular spasm is vasoconstriction of a damaged vessel to stop or slow flow of blood for 20 to 30 minutes to
“buy time” for other mechanisms to start working
p 704

19. Platelet Plug Formation
Platelet Adhesion = platelets stick to exposed collagen
Platelet Aggregation = platelets stick to each other & build up a mass called a platelet plug
Platelet Activation = platelets develop cytoplasmic processes (pseudopods) & degranulate (exocytosis of granule contents)
p 704

20. Platelet Activation: Degranulation
Granules contain:
ADP = primary stimulus for platelet aggregation & activation
Thromboxane A2 = stimulates aggregation, degranulation, & vasoconstriction
Serotonin = stimulates vasoconstriction
Platelet derived growth factors (PDGF) = promote division of endothelia, smooth muscle & fibroblasts
Ca++ = increases local supply
= POSITIVE FEEDBACK LOOP

21. Coagulation Three Basic Stages: 1) Form Prothrombin Activator
Extrinsic pathway
Intrinsic pathway
2) Form Thrombin
3) Form Fibrin
p 704

24. Clot Retraction Platelets contract and pull on fibrin strands
Clot becomes denser & stronger
Pulls edges of damaged vessel together
Squeezes out serum

25. Fibrinolysis Plasmin activated by; Factor XII Plasmin Thrombin
Tissue Plasminogen Activator (t-PA)
p 708

26. To Clot or Not to Clot Thrombin diluted by blood
Fibrin inactivates most of thrombin at wound
Liver removes active clotting factors from blood (leaves inactive factors)
Anticoagulants;
Antithrombin from liver inactivates thrombin
Heparin from mast cells & basophils helps prevent coagulation