Immune and Integumentary Systems

Immune System

Functions The immune system defends against disease. It recognizes, attacks, and destroys foreign invaders such as bacteria and viruses.

Organs Tonsils – lymph nodes in the throat Thymus – T-Cells made in the bone are matured here. Lymph Nodes – small bean-shaped masses Spleen – filters blood for foreign particles carried by the white blood cells. Bone Marrow – makes white blood cells.

Immune System Bone marrow Tonsils Thymus Lymph node Spleen Lymphatic vessel

Tissues White Blood Cells – blood cells whose main function is to defend the body against disease. Lymphocytes – white blood cells. oT-Cells – lymphocytes made in the bone marrow and mature in the Thymus gland whose function is to attack cells that have been invaded by viruses. oB-Cells – lymphocytes made in the bone marrow that make antibodies to attack viruses in the blood.

How It Works

1.Recognition – White Blood Cells identify the antigens that do not belong in the body. (viruses & bacteria) 2.Activation – White Blood Cells attach to the foreign cells or viruses and destroy them. 3.Disposal – foreign cells and viruses are filtered out of the blood in the spleen.

Integumentary System (Skin)

Functions Regulates body temperature Keeps germs out of the body Senses temperature, texture, pressure, and pain. Releases oil, waste and salt in sweat. Shields body from UV rays Produces vitamin D from UV rays. Provides waterproof covering that prevents dehydration.

Specialized Cells Epidermis – outer layer of skin mostly made up of dead cells. Dermis – functional layer of skin below the epidermis.

How It Works

Epidermis Keratin – strong flexible protein that make skin tough and waterproof. Melanin – pigment that gives skin its color and shields the body from UV rays.

Dermis Contains – blood vessels, nerves, sweat glands, oil glands, and hair follicles. Collagen – protein fibers that make skin flexible.