The Parts of the Immune System

1. The Parts of the Immune System

2. What will be covered? • Lymph • Lymphatic Vessels • Lymphatic Capillaries • Red Bone Marrow • Lymphocytes (introduction) • B Cells • T Cells • Thoracic Duct and Right Lymphatic Duct • Left and Right Subclavian Veins • Thymus • Spleen • Other Lymphatic Tissues

3. Lymph, Lymphatic Vessels, and Lymph Nodes • Lymph is a clear fluid composed of antibodies, water, fat molecules, and the same proteins, ions, and nutrients found in tissue fluid. • Its main purpose is to remove cell waste. • Lymph is found inside lymphatic capillaries and is filtered by lymph nodes. • Lymph nodes are small, bean-like structures located along lymphatic vessels. They clean lymph by removing bacteria, cancer cells, and other foreign substances. • Lymphatic vessels are similar to blood vessels because: • Lymph transport • Thoracic and right lymphatic ducts along with left and right subclavian veins • Lymphatic capillaries • Valves

4. Lymph Node

5. Lymphatic vessels and capillaries

6. Red Bone Marrow • All blood cells, including lymphocytes, are produced in the red bone marrow • Spongy, semi-solid red tissue • Children have more red bone marrow than adults because their bodies need more oxygen (more red blood cells) • Some of these lymphocytes become mature B cells while some become T cells (these mature in the thymus)

7. B Cells • Also called B lymphocytes, these cells form and mature in the red bone marrow • Responsible for forming antibodies • Each B cell has thousands of protein receptors that are attached to its membrane. These receptors are called membrane-bound antibodies. • Each antibody is a protein complex with 4 amino acid chains and a variable portion

8. T Cells • Form in the red bone marrow and are transported to the thymus via the bloodstream • Helper T Cells • Stimulate B cells to produce antibodies • Cytotoxic T Cells • Also called killer cells, these lymphocytes directly attack cells with unrecognized or foreign molecules and are especially useful in attacking viruses • http://www.youtube.com/watch?v=HNP1EAYLhOs

9. Thymus • Located in the thoracic cavity between the trachea and the sternum near the heart • Site of T cell maturation and selection • Divided into sections called lobules. Each lobule consists of two different patterns of cells: the outer pattern is the cortex and the inner pattern is the medulla • Also produces hormones such as thymosin that aid in T cell maturation • http://www.youtube.com/watch?v=hRh9Rb-XqMg

10. Spleen

11. Spleen • Oval organ with a dull purplish color. Located in the upper left of the abdominal cavity. • Mostly consists of red pulp that filters the blood • Red pulp consists of blood vessels and gaps called sinuses, where cells called microphages remove old and defective erythrocytes. • Also has white pulp within red pulp where B and T cells come together in lumps of lymphatic tissue. • Has a thin outer capsule, making it highly vulnerable to bursts.

12. Extra • Talk about tonsils • Overview: http://www.youtube.com/watch?v=6hyC-QH7wgo