The shape provides a combination of flexibility for moving through tiny capillaries with a maximum surface area for the diffusion of gases. The primary function of erythrocytes is to transport oxygen and, to a lesser extent, carbon dioxide.
Leukocytes, or white blood cells, are generally larger than erythrocytes, but they are fewer in number. Even though they are considered to be blood cells, leukocytes do most of their work in the tissues.
They use the blood as a transport medium. Some are phagocytic , others produce antibodies ; some secrete histamine and heparin , and others neutralize histamine.
Leukocytes are able to move through the capillary walls into the tissue spaces, a process called diapedesis. In the tissue spaces they provide a defense against organisms that cause disease and either promote or inhibit inflammatory responses.
Plasma carries water, salts and enzymes. The main role of plasma is to take nutrients, hormones, and proteins to the parts of the body that need it. Cells also put their waste products into the plasma. The plasma then helps remove this waste from the body. Blood plasma also carries all parts of the blood through your circulatory system. Plasma is a critical part of the treatment for many serious health problems.
This is why there are blood drives asking people to donate blood plasma. Along with water, salt, and enzymes, plasma also contains important components. Anaemia is the lack of haemoglobin or red blood cells. The symptoms of anaemia are pale skin colour and a loss of energy. White Blood Cells leucocytes are colourless cells and possess a nucleus. They function in defending the body against pathogens. These white blood cells are called phagocytes. Others, the lymphocytes produce antibodies, the specific defense proteins.
They are made by the bone marrow and lymphatic tissue. Lymphocytes are made in the bone marrow and then stored in various in various parts of the lymphatic system. Haemoglobin can combine reversibly with oxygen. This is important - it means that it can combine with oxygen as blood passes through the lungs, and release the oxygen when it reaches the cells. You may be given some prepared slides of blood to examine with the microscope. You will need to use a high magnification to examine them.
The slides will have been stained to show the cells, and cell features. The micrograph shows many red blood cells and three white blood cells.
Blood Blood is important in multicellular organisms because it flows around the body, transporting substances to and from cells. The composition of blood Blood transports materials and distributes heat around the body.
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