Defense Systems And Organs Of Human Body

The lymphatic system acts as a defense mechanism for the body that protects against harmful influences such as pathogens and cells within the body that are malfunctioning. Excluding the nervous system, the immune system is the most elaborate system in the body, consisting of organs, vessels called lymph vessels, and defense cells call lymphocytes.Defense Systems And Organs Of Human Body

The primary lymphoid organs, bone marrow and the thymus, regulate the production and development of lymphocytes. These defence cells are produced by the bone-marrow and developed by the thymus to be able to recognize non-self-proteins called antigens. There are two major kinds of lymphocytes: T cells and B cells. The T cells attack cells originating in the body that have become cancerous or have been infected by a virus. The B cells create antibodies for attacking pathogens. Lymphocytes carry out their work in the secondary organs of the lymphatic system, such as the lymph nodes. The lymph nodes are little gland-like clusters of tissue that store lymphocytes and filter out and destroy harmful substances from the lymphatic fluid. The larger ones then pass on the cleaned fluid into veins to enter the blood stream.Defense Systems And Organs Of Human Body

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The integumentary system is an organ system that protects the body from disease, UV light, chemicals, and abrasions. The human integumentary system consists of the skin, nails, hair, and exocrine glands. Hair and nails reinforce the skin and exocrine glands produce fluids such as sweat and oil to cool, moisturize, and protect it. A bird’s integumentary system is comprised of its skin, feathers, claws, and beak. Its skin covers the majority of its body and is fortified in certain places by the claws and beak. The feathers can be moved to trap air for insulation. This system protects the bird from outside harm, possesses compound capable of producing vitamin D from sun exposure, and acts as thermal insulation to regulate the bird’s temperature.

The main difference between humans’ and birds’ integumentary system is that people have hair to regulate body temperature, while birds use their feathers . A bird’s dermis, the middle layer of skin, is fairly thin and has a uniform, microscopic structure. It is made up of mostly collagen and small amounts of elastin. Human’s dermis is thicker and is made mostly of dense irregular tissue along with blood vessels and nervous tissue.Defense Systems And Organs Of Human Body