1. BIO 265 – Human A&P Chapter 17 - Blood

2. Preview of Circulation Figure 18.5

3. Functions of the Blood What are the functions of the blood? Distribution O 2, CO 2, nutrients, wastes, hormones Regulation Body temperature, blood pH, water balance, electrolytes, etc. Protection Prevention of blood loss (platelets and clotting) and infection (WBC’s) Figure 18.5

4. Composition of the Blood Plasma (55%) Formed elements (45%) What are the different types? Figure 17.1 and other figure

5. Plasma Plasma is the liquid portion of the blood that contains: 90-92% water many proteins Albumin – regulates water movement Globulins – antibodies, etc. Fibrinogen – clotting protein nutrients such as glucose and amino acids wastes such as CO 2 and urea electrolytes Plasma Donation

6. Formed Elements Figure 17.2

7. Red Blood Cells 95% of formed elements are RBCs or erythrocytes RBCs are donut-shaped cells that do not have a nucleus they are basically just bags of hemoglobin ~ 250 million molecules of hemoglobin per cell (1/3 of total cell vol.) Figure 17.3

8. Red Blood Cells 98.5% of the O 2 in the blood is carried by hemoglobin Hemoglobin is composed of 4 separate proteins (globins) Each protein has an iron containing heme group that binds to the O 2 Figure 17.4

9. Red Blood Cells (cont.) RBCs are also associated with CO 2 transport ~20% of CO 2 is bound to hemoglobin Figure 18.5

10. Red Blood Cells (cont.) RBCs only live about 120 days about 2.5 million RBCs die every second Most are removed in the liver and spleen RBC production is stimulated by low blood O 2 Causes Decreased RBC’s, pneumonia, high altitude, exercise Mt. Everest example

11. Red Blood Cells (cont.) Low blood O 2 triggers the release of erythropoitin from the kidneys Figure 17.6

12. Red Blood Cells (cont.) Old RBCs are broken down by macrophages Amino acids and iron are recycled Heme groups are converted to bilirubin that is transported to the liver Most bilirubin becomes part of bile Jaundice Figure 17.7

13. Red Blood Cells (cont.) RBC Disorders: Anemia – abnormally low oxygen-carrying capacity Can be caused by low levels of RBCs and/or hemoglobin Hemorrhagic anemia Hemolytic anemia Aplastic anemia Iron-deficiency anemia Pernicious anemia (vitamin B12 deficiency) Abnormal hemoglobin – sickle cell anemia Polycytemia Blood doping

14. White Blood Cells Also called Leukocytes How are they different from RBCs? Function? What types of WBCs are there? Table 17.2

15. Hemostasis Hemostasis is the arrest of bleeding When a blood vessel is damaged three things occur: Vascular spasm – an immediate, but temporary closure of a blood vessel Platelet plug formation Coagulation or clot formation Figures 17.13 and 17.14

16. Hemostasis Disorders: Thrombus – a stationary clot in an unbroken vessel Embolus → embolism Aspirin and heparin are anticoagulants Hemophilia

17. Hematopoiesis Hematopoiesis – formation of blood cells Figures 17.5, 17.11, and 17.12

18. Diagnostic Blood Tests Blood typing Rh factor and pregnancy Problem combination: Rh- mother/ Rh+ child Figure

19. Diagnostic Blood Tests Problem treated with Rhogam (antibodies against the Rh protein)

20. Diagnostic Blood Tests Complete blood count (CBC) White blood cell differential count Blood chemistry Fun Activity