By contracting, the heart works like a pump and pushes blood through the vessels, ensuring its continuous movement. When it stops, death occurs, since the delivery of oxygen

The lymphatic system ensures the movement of lymph through the lymphatic vessels and promotes the outflow of excess fluid from the tissues. Many tissues have tiny lymphatic capillaries

Platelets Platelets, or platelets, are thickened, non-nucleated plates with a diameter of 3-4 microns. The number of platelets in the blood is not constant. At different times in

Phagocytosis and the production of antibodies by leukocytes is a single defense mechanism called immunity. Characteristic Immunity – protection of the body from foreign substances and organisms. The

Leukocytes are white nucleated blood cells. 1 mm³ of blood usually contains 4-9 thousand leukocytes, but in some diseases their number can increase markedly. The main function of

For some diseases or blood loss, a person is given a blood transfusion. Blood for transfusion is taken from healthy adults – donors, special chemicals are added to

Erythrocytes, or red blood cells, are non-nuclear biconcave oval cells. Their number in 1 mm³ of human blood is approximately 5.5 million. Red blood cells are formed in

An adult’s body contains about 5 liters of blood. Blood composition The bulk of the blood is the liquid intercellular substance – plasma (55-60%), which contains the corpuscles

The internal environment is the fluids (blood, lymph and tissue fluid) that surround living cells and provide the necessary conditions for their life. The structure of the internal

Sudden careless movements, falls, impacts can lead to damage to bones and joints. Bruises Closed injuries that damage soft tissues and cause swelling or bruising (bruising) are called