1. Blood

2. Physical Characteristics of Blood
Color range
Oxygen-rich blood is bright red
Oxygen-poor blood is dull red
pH must remain between 7.35–7.45
Blood temperature is 100.4°F
Blood volume = 5–6 L adult male
4-5 L adult female
Blood is 8% of body weight.

3. What are the functions of blood?
Transports nutrients, wastes, oxygen, and hormones.
Defense against pathogens.
Restriction of blood loss (clotting)
Regulates electrolytes and pH in interstitial fluid
Distributes heat throughout body

4. Composition of Blood Formed Elements: 1. Erythrocytes (RBC)
2. Leukocytes (WBC)
3. Thrombocytes (platelets)
Plasma: 90% water and dissolved substances

5. Erythrocytes or RBC Biconcave shape Flexible Lack nuclei
Hemoglobin present
Function: To carry oxygen (also removes CO2)
Diet needs: iron, folic acid and vitamin B12
“Erythro” means red
Get Body Smart – RBC’s

6. Erythrocytes under the microscope

7. Hemoglobin Contains iron which O2 binds with.
Each hemoglobin contains 4 binding sites for oxygen.
250 million hemoglobin molecules per RBC!
Anemia is a decrease in the oxygen-carrying ability of the blood.
Sickle cell anemia (SCA) results from abnormally shaped hemoglobin.

9. Erythropoiesis Definition: Formation of RBC’s.
Location: Red bone marrow
All blood cells are derived from a common stem cell (hemocytoblast)
Wear out in 100 to 120 days
When worn out, RBCs are eliminated by phagocytes in the spleen or liver.
Rate of cell production controlled by the hormone Erythropoietin (EPO).

10. Hematopoiesis: Development of blood cells from
hemocytoblasts (stem cells) in bone marrow.

11. Thrombocytes or “The Platelets”11

12. Thrombocytes Made from Megakaryocyte stem cells
No nuclei, very tiny, and granules present.
Circulate freely, inactive until vessel injury
Function: “Hemostasis” (stoppage of bleeding)
Short life-span (5-9 days) 12

13. 13

14. Hemostasis (Click for animation)
Three mechanisms:
1. Vascular spasm – smooth muscle constricts blood vessel to prevent more loss.
2. Platelet plug formation – platelets adhere to exposed collagen fibers and to each other to plug hole.
3. Blood clotting (coagulation) – “molecular glue” that will result in a fibrin mesh with the help of clotting factors and procoagulants.
Vitamin K needed to form clotting factors.
Normal clotting time = 3-6 minutes 14

15. A scanning electron micrograph of fibrin threads.15

16. Atherosclerosis Animation
Platelet Problems
Thrombus – abnormal blood clot formed in an unbroken vessel.
Coronary thrombosis: blood clot forming in a heart blood vessel
Cerebral thrombosis: blood clot forming in a brain blood vessel
Deep Vein Thrombosis: blood clot forming in lower extremities animation
Embolus – traveling blood clot
Pulmonary embolism: clot that travels and blocks vessel that supplies the lungs.
Atherosclerosis – accumulation of fat deposits can initiate a thrombus to form.
Atherosclerosis Animation 16

17. The Plasma 17

18. What is in it?
Clear, straw-colored, liquid portion in which the cells and platelets are suspended.
Approximately 90% water
Includes many dissolved substances
Nutrients – glucose, amino acids, lipids
Electrolytes – Na+, K+, Ca2+ etc.
Respiratory gases - CO2, O2, N2
Hormones
Plasma proteins
Waste products – urea, uric acid, excess items 18

19. Plasma Functions Transports nutrients, gases, and vitamins
Helps regulate fluid and electrolyte balance
Maintains favorable pH

20. Plasma proteins
Most abundant of dissolved substances (solutes) in plasma
Most plasma proteins are made by liver
1. Albumins – regulate osmotic pressure
2. Globulins – antibodies & fat transport
3. Fibrinogen – blood clotting
4. Regulatory proteins – enzymes, clotting, and hormone transport. 20

21. White Blood Cells (Leukocytes)

22. Leukocyte Special Characteristics
Diapedesis
Reach infection site by slipping into and out of blood vessels
Ameboid motion
Move through tissue spaces to reach location
Chemotaxis
Respond to chemicals released by damaged cells in order to locate damaged area

23. Leukocytes
Function is to protect against infection in various ways: How???
Phagocytize bacterial/dead cells in the body
Produce proteins (antibodies) that destroy or disable foreign particles
Use chemicals to destroy pathogens or infected cells
Cytokines and interleukins – chemicals released by cells to activate WBC’s.
Pus – solution of WBC’s, bacteria and damaged cells.
“leuko” means white

25. Types of WBC’s Granulocytes (cytoplasmic granules)
Neutrophils
Eosinophils
Basophils
Agranulocytes (no cytoplasmic granules)
Lymphocytes
Monocytes

26. Neutrophils Most common type Multi-lobed nucleus
Phagocytic – will chase down bacteria!
Granules stain light purple/blue 
Numbers increase during bacterial & fungal infections

27. Eosinophils Fairly rare, not that common Bilobed nucleus
Red cytoplasmic granules.  
Involved in allergic reactions and parasitic infections…like worms!

28. Basophils EXTREMELY RARE! Dark blue granules
Bilobed nucleus present but difficult to see because of the dark granules
Involved in allergic reactions as producers of histamine and heparin to increase blood flow  

29. Monocytes Largest leukocyte No granules Horse-shoe shaped nucleus.
Phagocytic
Important in activating lymphocytes for specific immune response

30. Lymphocytes Very abundant No granules Cytoplasm minimally seen
Rounded nucleus almost size of entire cell
Close in size to RBC
Types: B or T
B’s - Antibody producing cells
T’s – chemically kills infected cells