HEART AND CIRCULATORY SYSTEM (Part-II)

Haemoglobin is found in red blood cells, and haemoglobin is a globular protein which transports oxygen (O₂) molecules throughout the body. Each haemoglobin protein structure consists of four polypeptide subunits, which are held together by ionic bonds, hydrogen bonds, hydrophobic interactions and Van der Waals forces, and four heme pigments, one in each of the subunits. These heme groups contain positively charged iron (Fe) molecules, which can reversibly bind to oxygen molecules and transport them to various areas of the body.

Anaemia is a condition in which the number of red blood cells or the haemoglobin concentration within them is lower than normal. The most common causes of anaemia include nutritional deficiencies, particularly iron deficiency, though deficiencies in folate, vitamins B12 and A are also important causes, haemoglobinopathies and infections such as malaria, tuberculosis, HIV and parasitic infections.

Iron is an essential element for blood production. About 70 percent of your body’s iron is found in red blood cells of your blood called haemoglobin and in muscle cells called myoglobin. Haemoglobin is essential for transferring oxygen in your blood from the lungs to the tissues. Myoglobin, in muscle cells, accepts, stores, transports and releases oxygen.

The tendency of haemoglobin to bind to CO is 250 times greater than that of oxygen. This is the reason why burning wood or coal in a closed space, even a small amount of CO can cause death, as it binds with haemoglobin to form the permanent compound carboxy - haemoglobin.

Erythrocytes, also known as red blood cells (RBCs), function to transport oxygen in the blood. They do so with the help of haemoglobin, a respiratory pigment. The shape and structure of erythrocytes are ideal for this function. They lack a nucleus and few other organelles so that maximum space in the cell can be used to accommodate haemoglobin molecules.

Haematopoiesis is the process that creates new blood cells within the body. Haematopoiesis occurs primarily within the bone marrow in adults, and within the bone marrow, liver, and spleen in children. Most blood cells are created in bone marrow, the spongy substance found inside a bone's structure. There are two types of marrow, red and yellow; both contain blood vessels and veins that transport nutrients and waste in and out of bones.

Haematopoiesis is the process that creates new blood cells within the body. Haematopoiesis occurs primarily within the bone marrow in adults, and within the bone marrow, liver, and spleen in children. Most blood cells are created in bone marrow, the spongy substance found inside a bone's structure. There are two types of marrow, red and yellow; both contain blood vessels and veins that transport nutrients and waste in and out of bones.

Plasma constitutes 55% of total blood volume. Composed of 90% water, salts, lipids, and hormones, it is especially rich in proteins, including its main protein, albumin, along with immunoglobulins, clotting factors, and fibrinogen. Plasma performs several functions: transporting blood cells and nutrients, regulating the body's water and mineral salts, irrigating tissues, defending against infections, and coagulating blood.

There are two levels of blood pressure in the arteries. The first is called systolic pressure and the second is called diastolic pressure. Normally, the systolic pressure in human arteries is 120 mm Hg and the diastolic pressure is 80 mm Hg. It is measured by the Sphygmomanometer instrument.

There are two levels of blood pressure in the arteries. The first is called systolic pressure and the second is called diastolic pressure. Normally, the systolic pressure in human arteries is 120 mm Hg and the diastolic pressure is 80 mm Hg. It is measured by the Sphygmomanometer instrument.