ANATOMY BLOOD

BLOOD

1. The important components of blood include plasma, erythrocytes, and leukocytes. Red blood cells or erythrocytes account for 45 % of the blood. Leukocytes or white blood cells, aid in protecting the body from disease as well as platelets. Platelets function to inhibit excessive bleeding from the body. The plasma layer is another layer that constitutes the majority of blood.

2. The Plasma is straw coloured. It has 90% water, 7%proteins and 3% other substances. The Plasma protects the cell, gives definite shape to the cell and it is permeable and able to regulate what enters and exits the cell.

3. Three types of plasma proteins are albumin, globulins, and fibrinogen.

4. The characteristics of red blood cells are that they are usually concave in shape, and usually have a fair bit of surface area on them. The function of red blood cells is to carry oxygen, and/or carbon dioxide to various portions of the body.

5. Hemoglobin transports oxygen from the lungs to the body tissues. When the oxygen concentration is a high in the alveoli, the hemoglobin combines with oxygen to form oxyhemoglobin. When the blood reaches the tissue with a low concentration of oxygen, the hemoglobin dissociates with the oxygen releasing the oxygen into the body tissues. 6. Leukocytes, also known as white blood cells protect the body against diseases. Granulocytes are about two times as large as a red blood cell, including eosinophil, basophils, and neutrophils. Neutrophils have small granules that appear light purple in neutral stain. Eosinophil has coarse, same-sized granules that appear dark red in acid stain. Basophils have lower amounts of granules that are also more irregular, and become deep blue in basic stain. Monocytes and lymphocytes are different types of basophils. Monocytes are the largest type of blood cells. Lymphocytes are little larger red blood cells, with large, round nuclei.

7. Platelets are small, disk shaped clear cell fragments, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days. The primary function of platelets is to prevent excessive internal or external bleeding after an injury. Platelets help to temporarily seal off the site of a wound by breaking away from other platelets and sticking to the exposed, damaged edges of blood vessels.

8. Granulocytes and Agranulocytes are both leukocytes however, granulocytes have a granular cytoplasm and Agranulocytes are those without granulocytes. 9. After an injury, spasms of smooth muscle in the blood vessel walls and accumulation of platelets at the site of vessel injury provide a temporary means of stopping or slowing blood loss. Coagulation of blood may be initiated by extrinsic or intrinsic pathways. Thromboplastin or tissue factor that are exposed to injury allows the extrinsic pathway to skip steps of the intrinsic pathway. A series of activated procagulants looks over the intermediate steps of each. These pathways converge as prothrombin is converted to thrombin.

10. Blood typing is very important. Blood typing consist of different types of blood that may not be compatible with each other. Agglutination describes the clogging of red blood cells after it has been transfused. This involves the red blood cells surface molecules called antigens that react with antibodies from the plasma. There are more than 260 antigens that are on the membranes of red blood cells. The ABO group is based on the different antigens present or the lack of two protein antigens, A and B. Type A blood can only use type A and not another antigen. Type B blood can only use type B however, type AB can use A or B antigens whereas blood type O serves the universal donor to all the other blood types, but it cannot receive. An Rh- person who receives Rh-positive blood will produce anti-Rh antibodies. In time, the Rh- person donated blood will begin to clump up.