The exchange of oxygen and carbon dioxide takes place in between the lungs and blood. The greater part of oxygen diffuses into the blood and at the same time, carbon dioxide diffuses out. Here the question is where the oxygen would go.
Haemoglobin is a respiratory pigment in RBCs. It is tetrameric conjugated protein. It consists of two parts: haem and globin. Haem is the non-protein part and made up of iron or ferrous (Fe++) containing perphyrins.
The difference between blood and lymph is that Blodd is red in colour due to presence of RBCs whereas lymphs are colourless due to absence of RBCs .
Blood is known as fluid connective tissue. Its fluid matrix is the plasma in which blood cells or corpuscles float freely and are carried on alongwith bloodstream. Its color is red and it is slightly alkaline having pH 7.3 to 7.5. In an adult man about 6-7 litres of blood is present.
Blood is a liquid tissue that circulates in a closed system of blood vessels. Total volume of blood in human body is 5.4 liters. In man, it may be 85 ml/kg body weight. The specific gravity of blood varies between 1.05-1.06.
The different sizes and types of blood vessels are involved in blood circulation. They range from thick-walled, wide vessels of 1 cm in diameter to fine capillaries with a diameter of a few microns.
The pressure of flow of blood in the aorta and its main branches is defined as blood pressure. The heart has to develop a high pressure so that blood can be pumped through the fine capillaries. This blood pressure varies from one part of body to another.
As blood is a life-saving fluid, it is often required for transfusions during operations and accidents. Without knowing its group it cannot be donated or received. The blood groups fall into four categories.
Blood capillaries are under some pressure from within and from without. As a result, some fluid, whose composition will be discussed later, leaks out. If this fluid were to accumulate in tissues and organs, there would a swelling of the body called oedema.
The left auricle receives oxygen-rich blood from the lungs. The oxygenated blood is carried from the lungs to the left auricle by four pulmonary veins. The left ventricle receives blood from the left auricle. The left ventricle pumps the blood into the biggest blood vessel of the body- aorta which distributes oxygen-rich blood to different parts of the body.