1. Blood

2. What is Homeostasis
It is the internal environment (and therefore survival itself)
Maintaining homeostasis is dependent on continual transportation of materials to and from body cells.
Blood is a complex solution and is vital to your ability to survive.

3. Composition and Function of Blood
Composed of plasma (55%) and formed elements (45%)
Used for transport of materials through the body
Used to regulate body heat (homeostasis)

5. How much blood do you have?
Amount of blood varies based on
Age
Body type
Gender
1 unit of blood = 0.5 liters

6. Solution = Solvent + Solute
Plasma
Liquid part of the blood – it is a solution
Remember……..
Solution = Solvent + Solute
Composed of water (90%) and mostly proteins (10%)

7. Solutes found in Plasma
Roughly 6% to 8% of the solutes found in plasma are made of protein.
Examples:
Albumins
Globulins
Fibrogen

8. Formed Elements of the Blood
Formed elements are all the chemicals (usually proteins) and cells found in the blood. The formed elements are:
Erythrocytes (Red Blood Cells)
Leukocytes (White Blood Cells)
Platelets (Cell fragments)

9. Erythrocytes Also called Red Blood cells Have no nucleus
Thin plasma membrane
Do not have ribosomes and mitochondria as well as other organelles
Shaped as a biconcave disk
7.5 mm in diameter
Filled with hemoglobin (Hb)
Most numerous formed element

10. Function of Erythrocytes
Transport oxygen and carbon dioxide
Ability to transport oxygen and carbon dioxide is based on the amount of hemoglobin

11. Hemoglobin
Hb is made of 4 globin protein chains – two alpha and two beta. (Fig 17-5, p. 533)
4 oxygen molecules carried by each Hb molecule
Normal Hb values:
Males: 14 g to 16 g/100 ml blood
Females: 12 g to 14 g/100 ml blood
Anemia—less than 10 g/100 ml blood

12. Erythropoiesis – The Formation of Erythrocytes
Begins in the red bone marrow as hemopoietic stem cells (hemocytoblast) go through several stages of development to become erythrocytes
Process takes about 4 days to complete.
Stimulus for increased RBC formation is low oxygen levels in the kidney
Stimulus for RBC formation is erythropoietin, produced continually by liver
Erythropoietin stimulates the hemocytoblasts to produce more RBCs

13. Destruction of Erythrocytes
RBCs last about 105 to 120 days
Macrophage cells in the liver and spleen phagocytose the old, abnormal or damaged cells.
Hemoglobin is broken down releasing the iron, amino acids and bilirubin.
Most components are recycled

14. Formed Element – Leukocytes (WBC)
Two major groups: Granulocytes and Agranulocytes
Granulocytes have granules in cytoplasm and lobed nuclei (p. 538)
Agranulocytes do not have granules in their cytoplasm (p. 536)

15. Types of Granulocytes - Neutrophils
Neutrophils: 65%–75% of total WBCs (Fig. 17-9)
Highly mobile and very active phagocytic cells
Cytoplasmic granules contain lysosomes.
Increase in numbers during acute infections

16. Types of Granulocytes - Eosinophils
Eosinophils: 2%–5% of circulating WBCs (Fig )
Numerous in lining of respiratory and digestive tract
Capable of ingesting inflammatory chemicals and proteins
Increase in numbers during allergic reactions and parasitic worm infections

17. Types of Granulocytes - Basophils
Basophils: 0.5%–1% of total WBCs (Fig )
Motile
Cytoplasmic granules contain histamine and heparin.
Increase in numbers during allergic reactions and periods of inflammation

18. Types of Agranulocytes - Lymphocyte
Lymphocytes: 20%–25% of total WBCs (Fig )
Two types of Lymphocytes are important in the immune response
Thymic lymphocytes (T lymphocytes, or T cells)
Bursal lymphocytes (B lymphocytes, or B cells)

19. Types of Agranulocytes - Monocyte
Monocytes: 3%–8% of total WBCs (Fig )
Become macrophages in the tissues

20. Formation of Leukocytes
Both Granular and Agranular Leukocytes mature from undifferentiated Hemopoietic adult stem cells (hemocytoblasts)
The hemocytoblasts that development neutrophils, eosinophils, basophils, and some lymphocytes and monocytes are found in red marrow
Other heomocytoblasts found in Lymphoid tissue develop into lymphocytes and monocytes.

21. Thrombocytes (Platelets)
In circulating blood, platelets are small, pale bodies that appear as irregular spindles or oval disks.
Plasma membrane-bound particles of cytoplasm containing clotting factors
2 to 4 mm in diameter
Three important properties
Agglutination – “clumping”
Adhesiveness – “sticking”
Aggregation – “together”

22. Thrombocytes (Platelets) Function
Important role in hemostasis and blood coagulation
Two major functions are:
Hemostasis = stoppage of blood flow. Platelet plug formed by platelets sticking together (sticky platelets)
Coagulation = formation of fibrin clot

23. Formation of Thrombocytes
Formed in Red Bone Marrow, lungs and spleen.
Hemopoietic adult stem cells (hemocytoblasts) form megakaryoblasts, which form megakaryocytes, from these form membrane-bound cytoplasmic fragments (platelets).
Average survival about 7 days

25. Blood Type Antigens

26. How does Blood Clot?