Structure and function of the cardiovascular system.

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The cardiovascular system consists of the heart, blood and blood vessels.
•The lymphatic system consists of the lymph, lymph vessels, lymph nodes, and Lymphoid organs (tonsils, appendix, spleen, and thymus gland).
•Because both systems circulate various substances throughout the body, they can serve as vehicles for spread of infection.

                                                    Anatomy of the human Lymphatic system

                                      Structure & function of the cardiovascular system.

•The heart circulates substances to and from tissue cells.
• Deoxygenated blood enters the right atrium from all parts of the body. It passes to the right ventricle and to the lungs.
• Oxygenated blood returns to the left atrium. It passes to the left ventricle and to all tissue cells.
• The center of the cardiovascular system is the heart.

•Blood vessels are the tubes that carry circulating blood throughout the body.
•Arteries and arterioles transport oxygenated blood away from the heart to different tissues of the body.
•Veins and venules bring blood to the heart.
•Materials are exchanged between blood and tissue cells at capillaries. Capillaries connect arterioles to venules.
•The blood itself is a mixture of cells and a liquid called plasma.
•The plasma transports dissolved nutrients to the body cells and removes wastes from the cells.

•The cells are known as Red blood cells (RBCs), White blood cells (WBCs), and platelets.
•Red blood cells or erythrocytes carry oxygen and some carbon dioxide (although most of the carbon dioxide in blood is dissolved in the plasma).
•White blood cells, or leukocytes, are involved in the body’s defense against infection.
•Some white cells, in particular the neutrophils, are phagocytes, and the B cells and T cells, two types of lymphocytes, play key roles in immunity.
•Platelets, or thrombocytes, function in blood clotting.