1. Blood
By: Dr. Holly Nash-Rule

2. Functions of blood
Distribution/transport - nutrients, wastes, gases, etc.
Communication, i.e., hormones
Prevention of fluid loss – hemostasis, osmosis
Maintenance of pH
Disease/ infection fighting
Heating/Cooling

3. Blood Circulation Powered by the pumping action of the heart
Functions of blood
Carries respiratory gases, nutrients, and hormones
Helps body regulate temperature
Blood volume
Males: 5–6 liters
Females: 4–5 liters

4. Composition of Blood Contains cellular and liquid components
A specialized connective tissue
Blood cells—formed elements
Plasma—fluid portion and fibrinogen
Hematocrit—measure of % RBC
Males: 47% ± 5%
Females: 42% ± 5%

5. Major Components of Whole Blood
Withdraw
blood and place
in tube.
Plasma
55% of whole blood
Least dense component
Buffy coat
Leukocytes and platelets
<1% of whole blood
Erythrocytes
45% of whole blood
Most dense component
Centrifuge the
blood sample.
Formed
elements 1 2

6. Blood Plasma Straw-colored, sticky fluid portion of blood
Approximately 90% water
Contains over 100 kinds of molecules
Ions—Na+ and Cl–
Nutrients—Sugars, amino acids, lipids, wastes, and proteins
Three main proteins
Albumin, globulins, and fibrinogen

7. Formed Elements Blood cells Erythrocytes, leukocytes, and platelets
Staining of blood cells
Acidic dye—eosin; stains pink
Basic dye—methylene blue; stains blue and purple

8. Photomicrograph of a human blood smear
Erythrocytes
Lymphocyte
Neutrophils
Photomicrograph of a human blood smear
Platelets
Monocyte

9. Erythrocytes
Oxygen-transporting cells—7.5 µm in diameter (diameter of capillary 8—10mm)
Most numerous of the formed elements
Females: 4.3–5.2 million cells/cubic millimeter
Males: 5.2–5.8 million cells/cubic millimeter
Have no organelles or nuclei

10. Erythrocytes Are packed with oxygen-carrying hemoglobin
Hemoglobin molecule bears four oxygen molecules
Each O2 molecule bears an iron molecule
Results in the oxidation of iron atoms of hemoglobin molecules
Gives blood its red color

11. Erythrocytes Pick up O2 at lung capillaries
Release O2 across other tissue capillaries
Structural characteristics contribute to respiratory function
Biconcave shape  30% more surface area
97% hemoglobin
Lack mitochondria
Do not consume O2 they pick up

12. Erythrocyte

13. Leukocytes—White Blood Cells (WBCs)
4,800–11,000/cubic millimeter
Protect the body from infectious microorganisms
Function outside the bloodstream in loose connective tissue
Circulating leukocytes leave the capillaries
Originate in bone marrow

14. Leukocytes—White Blood Cells (WBCs)
Two types of leukocytes
Granulocytes
Agranulocytes
Girls Never Eat Bananas
Around Long-armed Monkeys

15. Relative Percentages of the Different Types of Leukocytes
Formed
elements
Platelets
Leukocytes
Erythrocytes
Differential
WBC count
(All total 4,800–
10,800/l)
Neutrophils (50–70%)
Lymphocytes (25–45%)
Eosinophils (2–4%)
Basophils (0.5–1%)
Monocytes (3–8%)
Agranulocytes
Granulocytes

16. Granulocytes Neutrophils—most numerous WBC
Phagocytize and destroy bacteria
Nucleus—has two to six lobes
Granules pick up acidic and basic stains

17. Granulocytes Eosinophils—compose 1–4% of all WBCs Play roles in
Ending allergic reactions, parasitic infections
Granules pick up mostly acidic stain

18. Granulocytes Basophils—about 0.5% of all leukocytes
Nucleus—usually two lobes
Function in inflammation mediation
Granules secrete histamines
Granules pick up mostly basic stain

19. Agranulocytes Lymphocytes—compose 20–45% of WBCs
The most important cells of the immune system
Nucleus—stains dark purple
Effective in fighting infectious organisms
Act against a specific foreign molecule (antigen)

20. Agranulocytes Two main classes of lymphocyte
T cells—attack foreign cells directly
B cells—multiply to become plasma cells
Secrete antibodies

21. Agranulocytes Monocytes—compose 4–8% of WBCs The largest leukocytes
Nucleus—kidney shaped
Transform into macrophages
Phagocytic cells

22. Platelets Cell fragments Break off from megakaryocytes
Function in clotting of blood

23. Blood Cell Formation
Hematopoiesis—process by which blood cells are formed in red marrow
100 billion new blood cells formed each day

24. Bone Marrow as the Site of Hematopoiesis
Bone marrow—located within all bones
Red marrow—actively generates new blood cells
Contains immature erythrocytes
In adults, red marrow is located
Between trabeculae of spongy bone of axial skeleton
Appendicular girdles
Proximal epiphyses of humerus and femur

25. Bone Marrow as the Site of Hematopoiesis
Yellow marrow—dormant
Contains many fat cells
Located in the long bones of adults

26. Cell Lines in Blood Cell Formation
All blood cells originate in bone marrow
All originate from one cell type
Blood stem cell (pluripotential hematopoeitic stem cell)
Lymphoid stem cells
Give rise to lymphocytes
Myeloid stem cells
Give rise to all other blood cells

27. Proerythroblasts
Monoblasts
Megakaryoblasts
Myeloblasts

28. The End