1. Blood

2. Functions of Blood (12.1) Substance DITRIBUTION/TRANSPORTATION
REGULATION of substances
Body PROTECTION

3. Blood Functions: Distribution (12.1)
Blood transports:
Oxygen from the lungs and nutrients from the digestive tract
Metabolic wastes from cells to the lungs and kidneys for elimination
Hormones from endocrine glands to target organs

4. Blood Functions: Regulation (12.1)
Blood maintains:
Appropriate body temperature by absorbing and distributing heat to other parts of the body
Normal pH in body tissues using buffer systems
Adequate fluid volume in the circulatory system

5. Blood Functions: Protection (12.1)
Blood prevents blood loss by:
Initiating clot formation when a vessel is broken
Blood prevents infection by:
Synthesizing and utilizing antibodies
Activating WBCs to defend the body against foreign invaders

6. Physical Characteristics of Blood (12.1)
Average volume of blood:
5–6 L for males; 4–5 L for females
Viscosity (thickness) (where water = 1)
Average pH of blood is 7.4
Salinity = 0.85%
Reflects the concentration of NaCl in the blood
Temperature is 100F
slightly higher than “normal” body temperature
Blood accounts for approximately 8% of body weight

7. Composition of Blood (12.2)
Blood is the body’s only fluid connective tissue
Liquid = plasma (55%)
Formed elements (45%)
Erythrocytes, or red blood cells (RBCs)
Leukocytes, or white blood cells (WBCs)
Platelets - fragments of cells

8. Blood Plasma (12.6) Blood plasma components: Water = 90-92%
Inorganic/Organic substances = 6-8%
Important for
maintain osmotic pressure of the blood,
transport of lipids
works as a clotting protein.
transportation of nutrients such as glucose and urea
Regulation of blood pH (electrolytes)

9. Components of Whole Blood (12.2/12.3)
Plasma (55% of whole blood)
Buffy coat: leukocyctes and platelets (<1% of whole blood)
Formed elements
Erythrocytes (45% of whole blood) 1
Withdraw blood and place in tube
Centrifuge 2
Hematocrit – the volume percentage of RBC in a
sample of whole blood.
Males: 47% ± 5%
Females: 42% ± 5%

10. Erythrocytes (RBCs) 12.3 Biconcave disc
No nucleus, no centrioles, no organelles
Filled with hemoglobin (Hb) - 97% of cell contents
Essential for carrying oxygen
Most numerous of the formed elements
Dedicated to respiratory transport.

11. Blood Cell Production (12.4)
Hemopoiesis – blood cell production
Occurs in the red bone marrow
Axial skeleton and girdles
Epiphyses (end) of the humerus and femur
Marrow contains immature erythrocytes
Erythropoiesis – production of RBC’s.

12. Erythropoiesis (12.4)
Hemocytoblasts – produce myeloid stem cells which develop into proerythroblasts
Erythroblasts – has nucleus and is synthesizing hemoglobin molecules (4 days)
Reticulocyte – the nucleus is shed, but other organelles are still present making more proteins. After 2-3 days, the organelles are shed and the reticulocyte enters the blood stream.
Erythrocyte – Once the reticulocyte has been in the blood stream for 24 hours, it is considered a mature RBC.

13. Fate and Destruction of Erythrocytes (12.4)
The life span of an erythrocyte is 100–120 days
Travels about 750 miles in that time (Chicago to NYC)
Old erythrocytes become rigid and fragile, and their hemoglobin begins to degenerate
Dying erythrocytes are engulfed by macrophages
Heme and globin are separated
Iron is removed from the heme and salvaged for reuse

14. Hormonal Control of Erythropoiesis
Erythropoietin (EPO) release by the kidneys is triggered by:
Hypoxia due to decreased RBCs
Decreased oxygen availability
Increased tissue demand for oxygen
Enhanced erythropoiesis increases the:
RBC count in circulating blood
Oxygen carrying ability of the blood
RBC/Oxygen levels
EPO release
RBC production

15. Erythropoietin Mechanism
Imbalance
Start
Normal blood oxygen levels
Stimulus: Hypoxia due to decreased RBC count, decreased availability of O2 to blood, or increased tissue demands for O2
Imbalance
Increases O2-carrying ability of blood
Reduces O2 levels in blood .
Erythropoietin stimulates red bone marrow
Kidney (and liver to a smaller extent) releases erythropoietin
Enhanced erythropoiesis increases RBC count
Figure 17.6

16. Erythrocyte Disorders
Polycythemia
Abnormal excess of erythrocytes
Increases viscosity, decreases flow rate of blood
Anemia – blood has abnormally low oxygen- carrying capacity
Blood oxygen levels cannot support normal metabolism
Signs/symptoms include fatigue, paleness, shortness of breath, and chills

17. Erythrocyte Disorders
Sickle-cell anemia – results from a defective gene
Codes for an abnormal hemoglobin called hemoglobin S (HbS)
This defect causes RBCs to become sickle-shaped in low oxygen situations

18. Leukocytes (WBCs) 12.5
Leukocytes – complete cells with nucleus and organelles
4-8,000/mm3
Number increases in response to bacterial/viral invasion (over 11,000/mm3)
Protect the body from infectious microorganisms

19. Two major types of WBCs 12.5
Granulocytes include Neutrophils, Eosinophils, Basophils (ben)
Are 2x larger than RBC and only live for 12 hours
Have lobed nuclei
Are all phagocytic cells
Agranulocytes include Monocytes, Lymphyocytes
Live for months to years
Normal shaped nuclei
Lack granules

20. Granulocytes (12.5) Neutrophils account for 65-75% of WBC
Our body’s bacteria slayers
Eosinophils account for 1–4% of WBC
Lead the body’s attack against parasitic infections
Lessen the severity of allergies by phagocytizing immune complexes (ending allergic reactions)
Basophils account for 0.5-1% of all WBC
Releases histamine – inflammatory chemical that acts as a vasodilator and attracts other WBCs

21. Agranulocytes (12.5) Lymphocytes Account for 20-25% of WBC
The most important cells of the immune system
T cells - attack foreign cells directly
B cells - give rise to cells that produce antibodies
Monocytes account for 3–7% of WBC
They are the largest leukocytes
They leave the circulation, enter tissue, and differentiate into macrophages

22. Leukocyte disorders Leukocytosis Leukopenia Leukemia
WBC count is abnormally high at 11,000 cells per millimeter cubed. This is common during sickness
Leukopenia
decrease in WBC count - below 4,800 mm3
Leukemia
cancer of WBC
Bone marrow begins to make abnormal WBC’s that grow faster, and larger than normal cells.

23. Platelets “Thrombocyte”
Platelets are small cell fragments
Platelets function in the clotting mechanism by forming a temporary plug that helps seal breaks in blood vessels

24. BLOOD TYPING KEY TERMS
ANTIGEN: Proteins on the surface of red blood cells that determine blood type and stimulate B cells to produce antibodies.
ANTIBODY: Proteins that B cells of the immune system produced in response to non-self antigens (antibodies react with antigens)
AGGLUTINATION: Clumping of blood cells in response to a reaction between an antibody and antigen.

25. Human Blood Groups (12.9)
RBC membranes have antigens on their external surfaces
These antigens are:
Unique to the individual
Recognized as foreign if transfused into another individual
Promoters of agglutination
Presence or absence of these antigens is used to classify blood groups

26. Blood Groups (12.9)
Humans have 30 varieties of naturally occurring RBC antigens
The antigens of the ABO and Rh blood groups cause vigorous transfusion reactions when they are improperly transfused

27. ABO Blood Groups (12.9) The ABO blood groups consists of:
Two antigens (A and B) on the surface of the RBCs
Two antibodies in the plasma (anti-A and anti-B)

28. ABO Blood Groups

29. Rh Blood Groups (12.9)
85% of the population have the presence of the Rh antigen on RBCs = Rh+
15% - Lack of antigen indicated as Rh–
Anti-Rh are not spontaneously formed only in Rh– individuals
Only after the Rh– individual receives Rh+ blood will the anti-Rh antibodies form.
A second exposure to Rh+ blood will result in a negative transfusion reaction with agglutination.

30. Transfusion Reactions (12.9)
Transfusion reactions occur when mismatched blood is infused
Donor’s cells are attacked by the recipient’s plasma antibodies causing:
Diminished oxygen-carrying capacity
Clumped cells (agglutination) that impede blood flow
Ruptured RBCs that release free hemoglobin into the bloodstream
Circulating hemoglobin precipitates in the kidneys and causes renal failure

31. Fetal and maternal blood types (12.10)

32. Fetal and maternal blood types (12.10)
Rh- mom pregnant with an Rh+ fetus
Rh– mother becomes sensitized when Rh+ blood (from Rh+ baby or a Rh+ transfusion) causes her body to synthesis Rh+ antibodies
In a second pregnancy, Rh+ antibodies of a sensitized Rh– mother cross the placenta and attack and destroy the RBCs of an Rh+ baby

33. Determine the blood type..
Has A antigens
Universal donor
A antibodies
Universal recipient
AB antigens
Both Antibodies
Rh factor is present
NO antibodies
Type A
Type O
Type B
Type AB
Type AB
Type O +
Type AB

34. Blood Type testing (12.9)
When serum containing anti-A or anti-B antibodies is added to blood, agglutination (clumping) will occur.
Positive reactions indicate (clumping)
Signifying the correct blood type
BLOOD TYPE:
AB-
*antibodies serum

35. Blood type being tested
Blood Typing (12.9)
Blood type being tested
RBC antigen
Serum Reaction
Anti-A
Anti-B AB
A and B + B – A O
None