Which suspension would contain

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. There are two main groups of leukocytes in the blood.

The cells that develop granules in the cytoplasm are called granulocytes and those that do not have granules are called agranulocytes. Neutrophils, eosinophils, and basophils are granulocytes. Monocytes and lymphocytes are agranulocytes. Neutrophils, the most numerous leukocytes, are phagocytic and have light-colored granules.

Eosinophils have granules and help counteract the effects of histamine. Basophils secrete histomine and heparin and have blue granules. In the tissues, they are called mast cells. Lymphocytes are agranulocytes that have a special role in immune processes. Some attack bacteria directly; others produce antibodies. Thrombocytes, or platelets, are not complete cells, but are small fragments of very large cells called megakaryocytes.

Megakaryocytes develop from hemocytoblasts in the red bone marrow. Thrombocytes become sticky and clump together to form platelet plugs that close breaks and tears in blood vessels. Platelets stop bleeding in two main ways:. Platelets help blood to clot. Blood The composition of blood Blood transports materials and distributes heat around the body. Component Function s Plasma Transporting dissolved carbon dioxide, digested food molecules, urea and hormones; distributing heat Red blood cells Transporting oxygen White blood cells Ingesting pathogens and producing antibodies Platelets Involved in blood clotting Red blood cells Red blood cells also called erythrocytes transport the oxygen required for aerobic respiration in body cells.

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.

They have no nucleus so they can contain more haemoglobin. They are small and flexible so that they can fit through narrow blood capillaries. They have a biconcave shape - they are the shape of a disc that is curved inwards on both sides - to maximise their surface area for oxygen absorption. They are thin, so there is only a short distance for the oxygen to diffuse to reach the centre of the cell. Scanning electron micrograph of red blood cells.

A scanning electron micrograph of a lymphocyte. Transporting dissolved carbon dioxide, digested food molecules, urea and hormones; distributing heat. Red blood cells. Transporting oxygen. White blood cells. Ingesting pathogens and producing antibodies. Involved in blood clotting.