1. Blood

2. Objectives List the three primary functions of blood
List avg vol. of blood, viscosity, pH, % body weight
Distinguish between plasma and formed elements
Identify substances in plasma and distinguish among the 3 categories of proteins based on their purpose (albumins, globulins, fibrinogens)
Explain the procedure for hematocrit separation
List the 3 types of formed elements
List primary purpose of erythrocyte
Describe the composition of hemogloblin
List the life span of an erythrocyte and the destruction/recycling of the components when it is aged
Define hematopoiesis and list where in the body it occurs
List dietary requirements for erythropoiesis to occur

3. Functions of Blood Blood performs a number of functions dealing with:
Substance distribution
Brings: nutrients from dig. organs, O2 from lungs, hormones from endocrine glands
Take: waste (CO2, urea, uric acid, etc)
Regulation of blood levels of particular substances
Acid/Base balance of body fluids (buffer)
Vol. of blood flow to diff. areas of body
Body protection
Phagocytic wbc and antibodies
Release clotting factors

4. Physical Characteristics of Blood
Characteristics indicate individual health state
Average volume of blood:
5–6 L for males; 4–5 L for females (Normovolemia)
Hypovolemia - low blood volume
Hypervolemia - high blood volume
Viscosity (thickness) (where water = 1)
Due to formed elements (RBC)
Flows 5x slower than water
The pH of blood is 7.35–7.45
Blood accounts for approximately 8% of body weight

5. Composition of Blood
Blood is the body’s only fluid tissue (a connective tissue)
2 major components
Liquid = plasma (55%)
Formed elements (45%)
Erythrocytes, or red blood cells (RBCs)
Leukocytes, or white blood cells (WBCs)
Platelets - fragments of megakaryocytes in marrow

6. Components of Whole Blood
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 2
Centrifuge
Hematocrit
Males: 47% ± 5%
Females: 42% ± 5%

7. Blood Plasma Blood plasma components:
Clear, yellowish fluid suspends formed elements
Water = 90-92%
Proteins = 6-8%
Approx. 50 diff types found, classified into categories
3 Categories
Albumins
Thicken blood
Globulins
Serve as antibodies for immune response
Fibrinogen
Serve as clotting proteins

8. Blood Plasma Additional dissolved substances (2%)
Organic nutrients – glucose, carbohydrates, amino acids
Electrolytes – sodium, potassium, calcium, chloride, bicarbonate
Nonprotein nitrogenous substances – lactic acid, urea, creatinine
Respiratory gases – oxygen and carbon dioxide

9. Formed Elements Formed elements comprise 45% of blood
Erythrocytes, leukocytes, and platelets make up the formed elements
Only WBCs are complete cells
RBCs have no nuclei or organelles, and platelets are just cell fragments
Most formed elements survive in the bloodstream for only a few days
Most blood cells do not divide but are renewed by cells in bone marrow

10. Erythrocytes
RBCs

11. Erythrocytes Characteristics
Biconcave disc
Folding increases surface area (30% more surface area)
Anucleate, no centrioles, no organelles
End result - no cell division
No mitochondria means they generate ATP anaerobically
Prevents consumption of O2 being transported
Filled with hemoglobin (Hb) - 97% of cell contents
Hb functions in gas transport
Most numerous of the formed elements
Females: 4.3–5.2 million cells/cubic millimeter
Males: 5.2–5.8 million cells/cubic millimeter

12. Erythrocytes (RBCs)
Figure 17.3

13. Erythrocyte Function A protein called globin
Erythrocytes are dedicated to respiratory gas transport
Hemoglobin reversibly binds with oxygen and most oxygen in the blood is bound to hemoglobin
Composition of hemoglobin
A protein called globin
made up of two alpha and two beta chains
A heme molecule
Each heme group bears an atom of iron, which can bind to one oxygen molecule
Each hemoglobin molecule thus can transport four molecules of oxygen

14. Structure of Hemoglobin
Figure 17.4

15. Hemoglobin Oxyhemoglobin – hemoglobin bound to oxygen
Oxygen loading takes place in the lungs
Deoxyhemoglobin – hemoglobin after oxygen diffuses into tissues (reduced Hb)
Carbaminohemoglobin – hemoglobin bound to carbon dioxide
Carbon dioxide loading takes place in the tissues

16. Life Cycle of Red Blood Cells

17. Fate and Destruction of Erythrocytes
The life span of an erythrocyte is 100–120 days
Travels about 750 miles in that time
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
Stored as hemosiderin or ferritin in tissues
Transported in plasma by beta-globulins as transferrin

18. Fate and Destruction of Erythrocytes
Heme is degraded to a yellow pigment called bilirubin
Liver secretes bilirubin into the intestines as bile
Intestines metabolize bilirubin into urobilinogen
Urobilinogen leaves the body in feces, in a pigment called stercobilin
Globin is metabolized into amino acids which are then released into the circulation

19. Stages of Differentiation of Blood Cells
Figure 17.9

20. Production of Erythrocytes
Hematopoiesis – blood cell formation
Occurs in the red bone marrow (myeloid tissue)
Axial skeleton and girdles
Epiphyses of the humerus and femur
Marrow contains immature erythrocytes
Hemocytoblasts give rise to ALL formed elements
Lymphoid stem cells - give rise to lymphocytes
Myeloid stem cells - give rise to all other blood cells

21. Production of Erythrocytes: Erythropoiesis

22. Regulation and Requirements for Erythropoiesis
Circulating erythrocytes – the number remains constant and reflects a balance between RBC production and destruction
Too few red blood cells leads to tissue hypoxia
Too many red blood cells causes undesirable blood viscosity
Erythropoiesis is hormonally controlled and depends on adequate supplies of iron, amino acids, and B vitamins

23. 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

24. 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

25. Dietary Requirements of Erythropoiesis
Erythropoiesis requires:
Proteins, lipids, and carbohydrates
Iron, vitamin B12, and folic acid
The body stores iron in Hb (65%), the liver, spleen, and bone marrow
Intracellular iron is stored in protein-iron complexes such as ferritin and hemosiderin
Circulating iron is loosely bound to the transport protein transferrin

26. Erythrocyte Disorders
Polycythemia
Abnormal excess of erythrocytes
Increases viscosity, decreases flow rate of blood
Leads to rise in BP
If untreated can cause blood clots (thrombosis) and hemorrhage
Anemia
Reduction in # of RBCs or in amt of Hg per unit of blood
Several types
It is a symptom rather than a disease itself
Blood oxygen levels cannot support normal metabolism
Signs/symptoms include fatigue, paleness, shortness of breath, and chills

27. Anemia: Insufficient Erythrocytes
Hemorrhagic anemia
Result of acute or chronic loss of blood
Hemolytic anemia
Prematurely ruptured erythrocytes
Aplastic anemia
Destruction or inhibition of red bone marrow
aplastic anemia

28. Anemia: Decreased Hemoglobin Content
Iron-deficiency anemia results from:
A secondary result of hemorrhagic anemia
Inadequate intake of iron-containing foods
Impaired iron absorption
Pernicious anemia results from:
Deficiency of vitamin B12
Lack of intrinsic factor needed for absorption of B12
Treatment is intramuscular injection of B12

29. Anemia: Abnormal Hemoglobin
Thalassemias
Absent or faulty globin chain in hemoglobin
Erythrocytes are thin, delicate, and deficient in hemoglobin
documentary
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

30. Leukocyte Objectives
Differentiate between leukocytosis, leukopenia and leukemia
Differentiate between two main categories of leukocytes
Name the 3 different types of lymphocytes listing each purpose of the specific cell type
Be able to discuss differences between lymphocytes and monocytes in terms of quantity, function and structure
List features of the granular cells that are different that agranular cells ( ability to be stained, life span, nuclei)
Name the 3 types of granular cells- distinguish between them in terms of %, function, life span
Explain PMN/poly abbreviation for neutrophils
Define leukemia,origin of different types, treatment
Define platelets and explain function

31. Leukocytes (WBCs)
Leukocytes, the only blood components that are complete cells:
4, ,000/cubic millimeter
Leukocytosis
WBC count over 11,000/mm3
Normal response to bacterial or viral invasion
Leukopenia
A decrease in WBC count below 4,800/mm3
Leukemia - a cancer of WBC

32. Leukocytes Purpose Mobile units of body’s defense system
“Seek and Destroy” Functions
Destroy invading microorganisms
Destroy abnormal cells (ie: cancer)
Clean up cellular debris (phagocytosis)

33. Leukocyte Type Two main categories Agranular Granular Lymphocytes
Monocytes
Granular
Neutrophils
Eosinophils
Basophils

34. 5 - Types of WBC’s Each WBC has a specific function Granulocytes
Agranulocytes
Each WBC has a specific function

35. Agranulocytes: Lymphocytes
Account for 25-30% or more of WBCs and:
Absence of granules in cytoplasm when stained (however do contain lysosomes)
Most important cells of the immune system
There are three types of lymphocytes:
T cells
B cells
Natural killer cells

36. Agranulocytes: Lymphocytes
T cells - attack foreign cells directly, helps restore immune system after infection; (cell- mediated immunity)
B cells - produce antibodies that bind to pathogens to enable their destruction (humoral immunity)
Natural killer cells – kills cells of the body that are displaying a signal to them (due to virus/cancer infection)

37. Agranuloctes: Monocytes
Monocytes account for 3–7% of leukocytes
They are the largest leukocytes
U- or kidney-shaped nuclei
They leave the circulation, enter tissue, and differentiate into macrophages
Clean up dead cell debris and attack microorganisms

38. Agranuloctes: Monocytes
Animation
Microscope

39. Granulocytes Granulocytes – neutrophils, eosinophils, and basophils
Contain cytoplasmic granules that stain specifically (acidic, basic, or both) with Wright’s stain
Are larger and usually shorter-lived than RBCs
Have lobed nuclei
Are all phagocytic cells

40. Granulocytes: Neutrophils (Polymorphonuclear leukocytes)
Account for 60-70% of total WBC’s
Life span short (~ 5 days)
Function
Neutrophils are our body’s bacteria slayers
AKA “polys” or PMN’s because multi-lobed nucleus can appear has multiple nuclei(polymorphonuclear)
Present in large amounts of pus

41. Granulocytes: Eosinophils
Eosinophils account for 1–4% of WBCs
Life span short (~10 days)
Function
Lead the body’s counterattack against parasitic infections
Lessen the severity of allergies by phagocytizing immune complexes (ending allergic reactions)

42. Granulocytes: Basophils
Rare:Account for 0.5-1% of all WBCs
Life span short (~few hours – few days)
Function
Release histamine for inflammatory response
Histamine – inflammatory chemical that acts as a vasodilator and attracts other WBCs (antihistamines counter this effect)

43. Formation of Leukocytes
All leukocytes originate from hemocytoblasts
The mother of all blood stem cells
Hemocytoblasts differentiate into myeloid stem cells and lymphoid stem cells
Myeloid stem cells become myeloblasts or monoblasts
Granulocytes form from myeloblasts
Monoblasts enlarge and form monocytes
Lymphoid stem cells become lymphoblasts
Lymphoblasts develop into lymphocytes

44. Formation of Leukocytes
Figure 17.11

45. Leukocytes Disorders: Leukemias
Leukemia refers to cancerous conditions involving white blood cells
Leukemias are named according to the abnormal white blood cells involved
Myelocytic leukemia – involves myeloblasts
Lymphocytic leukemia – involves lymphocytes
Acute leukemia involves blast-type cells and primarily affects children
Chronic leukemia is more prevalent in older people

46. Leukemia
Immature white blood cells are found in the bloodstream in all leukemias
Bone marrow becomes totally occupied with cancerous leukocytes
Severe anemia ensues due to excess production of WBC’s
The white blood cells produced, though numerous, are not functional
Death is caused by internal hemorrhage and overwhelming infections
Treatments include irradiation, antileukemic drugs, and bone marrow transplants

47. Platelets Platelets are fragments of megakaryocytes
Platelets function in the clotting mechanism by forming a temporary plug that helps seal breaks in blood vessels