Components of blood and blood pressure

It gives a brief and simple details about the blood, its components and blood pressure.

1. COMPONENTS OF BLOOD AND BLOOD PRESSURE Prepared by: Javeria Khan, M arium T anveer & S hezah S hahid

2. Introduction Blood is basically a fluid tissue consisting of blood cells and platelets. 55% of whole blood is plasma and rest 45% is the blood cells and platelets. Plasma

3. Plasma Plasma is a pale yellowish liquid. In plasma, 90% is water in which substances are dissolved as such: Soluble proteins such as serum albumin , serum globulin, fibrinogen and prothrombin Dissolved minerals such as chlorides, bicarbonate, sulphates and phosphates of sodium and potassium and calcium salts. Food substances like glucose, fats and amino acids Urea, uric acid and creatinine Hormones

4. Red blood cells Red blood cells are also known as erythrocytes. Red blood cell is a circular, flattened, biconcave disc making the center of the cell thinner than its edge. It does not have a nucleus. As it is elastic, it can squeeze through the capillaries smaller than itself in diameter. There are about 5 000 000 red blood cells in each cubic millimeter of blood. Red blood cells are produced by bone marrow. They have a lifetime of 3 to 4 months. Red blood cells contain a pigment known as hemoglobin, which contains iron that enables it to transport oxygen from lungs to all the cells in the body. RBCs act as a carrier to transport oxygen to the parts of the body.

5. White Blood Cells White blood cells are colorless and do not contain hemoglobin. They are larger than red blood cells and fewer in number. Each white blood cell is regular in shape and contains a nucleus. It can move. It can change its shape and squeeze through the walls of the fine blood capillaries into the spaces among the tissue cells. Their main role is to protect the body against disease causing microorganisms such as bacteria and viruses.

6. Kinds of WBCs ( Lymphocytes) Lymphocytes are produced by the lymph glands. Each lymphocytes has a large, rounded nucleus and small amount of non-granular cytoplasm. They make up about 25% of white blood cells. They tend to be nearly round in shape and only show limited movements. When a lymphocyte detects foreign antigens on a bacterium or virus, it makes chemicals called antibodies, which it secretes into plasma. The antibodies stick to the surface antigens on the pathogen, and destroy it. They do this by causing bacterium to burst open or to make bacteria stick together in clumps so that phagocytes can deal with them easily or by neutralizing toxins or acting as a label on a pathogen. Lymphocytes remains in bodies for many years.

7. Kinds of WBCs ( Phagocytes) Phagocytes are produced by bone marrow. They are so called because they can ingest foreign particles like bacteria. The majority of white cells in blood ( about 60-70% ) are phagocytes. They have an unusual irregular lobe-shaped nucleus. These cells can move around like amoeba and change their shape, producing extensions of the cytoplasm called pseudopodia. There are two kinds of phagocytes, namely, monocytes and polymorphs. A monocyte has a bean-shaped nucleus. A polymorph has a nucleus with many lobes and granular cytoplasm.

8. PLATELETS Platelets are the fragments of cytoplasm from bone marrow. It plays a important part in clotting of blood. Clotting is a necessary process that can prevent you from losing too much blood Platelets and damaged tissues produce a enzyme called thrombokinase.   Prothrombin is converted into thrombin (active) with the help of thrombokinase and calcium ion. Thrombin converts the soluble fibrinogen into insoluble threads of fibrin. Vitamin K is important for the blood clot. Heparin prevents the clotting of blood in undamaged blood vessels.

9. Blood pressure Q: what is blood pressure? Blood pressure is the force of blood exerted on the walls of blood vessels. Q: what is systole? When the ventricles contract blood flows from ventricles to blood vessel and to prevent the backward flow of blood bicuspid and tricuspid valves close which produce a “ lub sound”. Blood pressure is highest during systole .

10. Blood pressure Q: what is diastole? When ventricles relax they receives the blood from the the atrium and to prevent the backward flow of blood in the blood vessels ( pulmonary artery and aorta) the semilunar valves closes and this closer produce a “dub” sound. Blood pressure decrease during diastole.

11. Blood pressure Blood pressure is high in arteries. It is highest near aorta. Blood pressure is low in veins. Blood pressure is lowest in Vena Cava Range of systolic pressure: 120-140 mm of mercury Range of diastolic pressure: 75-90 mm of mercury Sphygmomanometer is used to measure blood pressure . One heart beat is made up of systole and diastole.