1. Blood
Chapter 12

2. Functions of Blood Considered a type of connective tissue
Deliver O2 and nutrients to all body cells
Transport waste products from cells for elimination
Transport hormones
Maintain body temp (distribute heat)
Maintain pH (carry buffers)
Maintain fluid volume
Prevent blood loss (clotting)
Prevent infection (WBCs, antibodies)

3. Blood Components Plasma (55%)
Water (90%), ions, proteins, gases, nutrients, wastes, hormones
Hematocrit (45%)
RBCs, WBCs, platelets
Develop from stem cells in bone marrow

5. Blood Volume Average about 5 liters Depends upon Body size
Fluid and electrolytes
Fat tissue

6. Erythrocytes Red blood cells (RBCs) Transport O2 in blood
Biconcave discs
Anucleate (no nucleus)
Leaves room for hemoglobin
Hemoglobin: iron-containing protein, binds to O2
Oxyhemoglobin – oxygen combined with hemoglobin
Bright red
Cyanosis - Blue coloration near surface of skin due to the build-up of deoxygenated blood
Life span: days

7. Red Blood Cell Count Male 4.6 - 6.2 mill/mm3 Female 4.2 - 5.4 mill/mm3
Linked to O2 capacities
Used for disease diagnosis
Evaluate course of disease

8. Destruction of RBC’s
RBC’s become fragile due to passing through capillaries
Macrophages conduct phagocytosis (in liver & spleen)
Hemoglobin broken down into heme and globin
Heme decomposed into iron and biliverdin
Iron recycled and stored in liver
Biliverdin converted into bilirubin
Excreted as bile as bile pigments
Jaundice
Bilirubin accumulates
Yellowing of skin and eyes

9. Jaundice

10. Blood Cell Formation Hematopoiesis: blood cell formation
Embryo and fetus – occurs in yolk sac, liver, and spleen
Adults - occurs in red bone marrow
Hemocytoblast: stem cell for RBC, WBC, platelets

11. RBC Hematopoiesis Dietary requirements: Iron for hemoglobin
Vitamin B12 and folic acid for DNA synthesis of all cells
Iron for hemoglobin
Anemia: decrease in oxygen-carrying ability of blood
Low RBC count or deficient hemoglobin content
Sickle-Cell Disease: abnormal hemoglobin
Genetic disorder
Carriers of 1 allele are resistant to malaria in Africa
Heterozygote advantage

12. Negative Feedback Mechanism
Erythropoietin
Hormone released in response to low oxygen concentration (hypoxia)
Detected by kidneys and liver
Travels to red bone marrow for RBC production

14. Leukocytes White blood cells (WBCs)
Types: neutrophils, eosinophils, basophils, lymphocytes, monocytes
Defend body against infection and tumors
Phagocytosis
Many lysosomes
Neutrophils and monocytes
Antibodies (Immunity)
Lymphocytes
Locate areas of tissue damage by responding to chemicals

15. WBC Counts Normal: 5,000-10,000/mm3 Differential WBC count
lists %’s of types of leukocytes present
Leukocytosis
> 10,000/mm3
Appendicitis, leukemia (acute and chronic)
Leukopenia
< 5,000 /mm3
Typhoid fever, flu, measles, mumps, polio, AIDS

16. WBC Counts
Leukemia: bone marrow becomes cancerous  huge numbers of WBCs
Treatment: chemotherapy, radiation, stem cell transplant

17. Types of WBC Agranulocytes Monocyte – phagocytic
Lymphocyte – key players in immune response
Granulocytes
Neutrophils – phagocytic
Eosinophils – moderate allergic reactions and regulate parasitic infections
Basophils – release histamine to promote inflammation and heparin to inhibit blood clotting during tissue damage

18. Platelets Cell fragments of megakaryocytes
Large cells in marrow that shatter
130, ,000/mm3 normal count
Functions
Close breaks in vessels
Initiate formation of blood clots

19. Plasma Plasma proteins Clear, straw-colored, liquid portion of blood
~ 92% is H20
Functions:
Transport nutrients, gases, and vitamins
Fluid and electrolyte balances
Maintaining pH (~ 7.45)
Plasma proteins
Albumin – maintain osmotic pressure
Globulins – transport lipids and fat-soluble vitamins
Fibrinogens – role in blood coagulation

20. Hemostasis = stoppage of bleeding
Vascular spasm
Constrict damaged blood vessels
Serotonin causes smooth muscle contraction
Platelet plug forms
Platelets stick and bind to damaged site
Release chemicals to attract more platelets
Coagulation
Blood clotting
Fibrin threads forms mesh that traps RBCs
Time: blood clot normally forms within 3-6 min.

22. Hemostasis - Coagulation
Prothrombin
Vitamin K needed to make prothrombin
Converted to thrombin in the presence of calcium
Thrombin fragments catalyze a reaction to convert:
Fibrinogen into fibrin which sticks to the vessel walls and traps cell and platelets
Positive feedback mechanism
Original action stimulates more of the same action

24. Disorders Thrombus: clot in unbroken blood vessel
Coronary thrombosis = heart attack
Embolus: thrombus breaks away from vessel wall and floats freely
Cerebral embolus = stroke
Hemophilia: hereditary bleeding disorder, lack clotting factors

25. Human Blood Groups
Antigen (agglutinogens): foreign substance (invader) that immune system recognizes
Antibodies (agglutinins): Y-shaped proteins secreted by WBC’s that attach to antigens
Agglutination: clumping caused by antibodies binding to antigens on RBCs
RBC surface proteins:
A antigen
B antigen
Rh antigen

26. ABO Blood Groups
43%
42%
12% 3%
Type A: has A antigen on surface of RBC
Type B: has B antigen
Type AB: has both A & B antigens
Type O: has no antigens on surface
Rh antigen found on RBC’s in Rhesus monkeys (1940)

27. Rh Factor in Pregnancy Rh+ Have antigens Rh- Do not have antigens
Problem occurs when female is Rh- and baby is Rh+
Problem is with future pregnancies
Erythroblastosis fetalis can develop in newborn
Treated with RhoGAM shots

33. Blood Typing Analysis Blood sample mixed with 3 antibodies
If blood clumps, antigens are present
If no clumps, no antigens are present
Anti-A antibody test
Rh antibody test
Anti-B antibody test

34. Blood Typing Identifying the antigens
Finding out if A, B, or Rh are present
Why?
Transfusions
Serious reactions may occur