BIO 265 – Human A&P

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 • O2, CO2, 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 CO2 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 O2 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 O2 • Figure 17.4

9. Red Blood Cells (cont.) • RBCs are also associated with CO2 transport • ~20% of CO2 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 O2 • Causes • Decreased RBC’s, pneumonia, high altitude, exercise • Mt. Everest example

11. Red Blood Cells (cont.) • Low blood O2 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