2. Blood Blood: it’s a red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. Also produce by bone marrow. Blood is transported throughout the body by the circulatory system (artery and vein).

3. Arterial blood is the means by which oxygen and nutrients are transported to tissues. Venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys for removal from the body.

4. 1. Transports: Dissolved gases (e.g. oxygen, carbon dioxide) Waste products of metabolism (e.g. water, urea) Hormones Enzymes Nutrients (such as glucose, amino acids, micro- nutrients (vitamins & minerals), fatty acids, glycerol) 2. Regulation of Body Temperature 3. Controls of body PH: The pH of blood must remain in the range 6.8 to 7.4, otherwise it begins to damage cells. 4. Removes toxins from the body

5. Blood composition: It composed of two parts: fluid and cellular. The fluid part is known as blood plasma that makes 55% of total blood volume and the rest comprises the cellular elements.

6. Plasma Plasma: blood cells suspended in a liquid called blood plasma, which constitutes about 55% of blood volume. It has a straw-color. Plasma Composition: 90% Water 8% Protein,. Approx. 55% Albumin, Approx. 38% Globulin. Approximately 7% fibrinogen. 0.9% Inorganic Salts (Sodium, Potassium, Calcium, Phosphate) 1.1% organic substances, blood glucose, urea, uric acid, ammonia.

7. Serum Serum: is the liquid remaining after blood clots. It’s essentially the same as plasma, except that the clotting factors and fibrinogen have been removed

8. Cellular Elements: 1.Red Blood Cells (Erythrocytes); Red Blood Cells (Erythrocytes): Red blood cells (RBCs) are the most common type of blood cell %41 of the blood cell, which mainly consist of haemoglobin, that capable to combine with oxygen molecules in the lungs and release them throughout the body. Normal RBCs are biconcave disc shape.blood cell haemoglobin 2-Platelets (Thrombocytes) Participate in hemostasis / coagulation

10. 3. White Blood Cells (Leukocytes) 3. White Blood Cells (Leukocytes): %4 White blood cells or leucocytes are special cells that are whitish in colour because they lack haemoglobin. They are large than erythrocytes and they have a nucleus. Leukocyte functions to protect the body against microorganisms, and they remove dead cells and debris from the tissues by phagocytosis. Classification in two groups (WBC): A-Granulocytes (Neutrophils, Eosinophils and Basophils) B-A granulocytes (Lymphocytes and Monocytes)

11. Three kinds of Granulocytes NEUTROPHILS Neutrophils are the most common granulocyte. They have segmented nuclei, typically with 2 to 5 lobes connected together by thin strands of chromatin which can be difficult to see; the cell may thus appear to have multiple nuclei. EOSINOPHILS This granulocyte has large granules which are acidophilic. The nucleus often has two lobes connected by band of nuclear material. BASOPHILS Basophils are the least common type of the white blood cells. The basophilic granules in this cell are large.

13. Two kinds of A granulocytes. MONOCYTES Monocytes are the largest cell type seen in blood smears. Their nuclei are like kidney or oval shape. Monocytes which remove dead cell debris as well as attacking organisms. LYMPHOCYTES The lymphocyte is agranular cell with very clear cytoplasm. Its nucleus is very large.