Power Point Presentation to Accompany 2010 Delmar Cengage

Power. Point Presentation to Accompany © 2010 Delmar, Cengage Learning

Chapter 15 The Lymphatic System © 2010 Delmar, Cengage Learning 2

Introduction • • Transports lymph through lymphatics Lymphatics: lymph capillaries and vessels Controls body fluid Destroys harmful microorganisms © 2010 Delmar, Cengage Learning 3

The Functions of the System and the Structure and Functions of the Lymphatic Vessels © 2010 Delmar, Cengage Learning 4

Introduction • Drain interstitial fluid from tissue spaces – Prevent edema • Transport digested fat to blood – Lacteals: special lymphatics in small intestine – Chyle: milky lymph in lacteals • Develop immunities • Produce lymphocytes © 2010 Delmar, Cengage Learning 5

Lymphatic Vessels • Lymph capillaries: blind-end tubes • Lymph capillaries are located between cells • Lymph capillaries unite to form lymphatics • Lymphatics converge into two main channels – Thoracic duct and right lymphatic duct © 2010 Delmar, Cengage Learning 6

Lymph Nodes • Found along lengths of lymphatics • Efferent: exit lymph node at the hilum • Afferent: enter lymph node at various locations • Trabeculae: divide the node into compartments • Germinal centers of compartments produce lymphocytes © 2010 Delmar, Cengage Learning 7

Lymph Circulation © 2010 Delmar, Cengage Learning 8

Lymph Circulation (cont’d. ) • Interstitial fluid: plasma in interstitial spaces • Lymph: interstitial fluid in lymph capillaries – Passes into lymphatics • Lymphatics join to form lymph trunks © 2010 Delmar, Cengage Learning 9

Lymph Circulation (cont’d. ) • Lymph circulation maintained by: – Normal skeletal muscle contractions • Compresses lymph vessels and forces lymph in one direction – Respiratory or breathing movements – Smooth muscle in lymphatic vessels © 2010 Delmar, Cengage Learning 10

Lymph Circulation (cont’d. ) • Lymph trunks – Lumbar: drains lower extremities and pelvis – Intestinal: drains abdominal region – Bronchomediastinal and intercostal: drain thorax – Subclavian: drains upper extremities – Jugular: drains head and neck © 2010 Delmar, Cengage Learning 11

Lymph Circulation (cont’d. ) • Individual trunks drain into two main trunks – Thoracic duct: drains into the left subclavian vein – Right lymphatic duct: drains into the right subclavian vein © 2010 Delmar, Cengage Learning 12

The Organs of the Lymphatic System © 2010 Delmar, Cengage Learning 13

The Organs of the Lymphatic System (cont’d. ) • Tonsils – Palatine, pharyngeal and lingual – Protect the nose and oral cavity • Thymus: lymphocyte production and maturation • Peyer’s patches: found in walls of small intestine © 2010 Delmar, Cengage Learning 14

The Organs of the Lymphatic System (cont’d. ) • Spleen – Largest mass of lymphatic tissue – Phagocytizes worn-out RBCs and platelets • Recycles hemoglobin – Produces lymphocytes and plasma cells – Stores blood for release during hemorrhage © 2010 Delmar, Cengage Learning 15

The Organs of the Lymphatic System (cont’d. ) • External view of the Spleen © 2010 Delmar, Cengage Learning 16

Immunity © 2010 Delmar, Cengage Learning 17

Immunity (cont’d. ) • Ability of body to resist – Infection from pathogens – Damage from foreign substances and harmful chemicals • Humoral immunity – B lymphocytes: produce antibodies • Fight circulating bacteria and viral infections • Become plasma cells when they enter tissues © 2010 Delmar, Cengage Learning 18

Immunity (cont’d. ) • Cellular immunity – T lymphocytes • Come from thymus glands • Fight intracellular viruses, fungi, parasites, cancer © 2010 Delmar, Cengage Learning 19

Antigens and Antibodies © 2010 Delmar, Cengage Learning 20

Antigens and Antibodies (cont’d. ) • Antigen: foreign protein in our body • B lymphocytes – Produce antibodies in response to antigens – Antibodies bind to specific antigen – Antigens precipitate – Phagocytic WBCs eat the antigens © 2010 Delmar, Cengage Learning 21

Antigens and Antibodies (cont’d. ) • Antibody morphology – Four amino acid chains linked by disulfide bonds • Heavy and light chains – Y shaped molecule – Binding sites at tips of Y – Stem of the Y is always constant © 2010 Delmar, Cengage Learning 22

Antigens and Antibodies (cont’d. ) • Antibody types – Ig. G: attacks viruses, bacteria, and toxins; activates complement – Ig. A: found in exocrine gland secretions – Ig. M: response to bacteria or food antigens – Ig. D: found on surface of B lymphocytes – Ig. E: associated with allergic reactions © 2010 Delmar, Cengage Learning 23

Antigens and Antibodies (cont’d. ) • Active immunity: B cells contact antigen and produce antibodies – Natural active: exposure to infection – Artificial active: vaccine • Passive immunity – Natural passive: maternal antibodies to fetus – Artificial passive: gamma globulin © 2010 Delmar, Cengage Learning 24

Cells of the Immune Response and Other Defenses © 2010 Delmar, Cengage Learning 25

Cells of the Immune Response and Other Defenses (cont’d. ) • B cells: antigen – Antibody binding • Plasma cells: replicated B cells • Helper T cells: stimulate production of – Killer T cells – More B cells © 2010 Delmar, Cengage Learning 26

Cells of the Immune Response and Other Defenses (cont’d. ) • Killer T cells: – Attack virus-invaded body cells – Attack cancer cells – Reject body grafts • Memory cells: descendents of activated T and B cells • Suppressor T cells: slow down activities of B and T cells © 2010 Delmar, Cengage Learning 27

Cells of the Immune Response and Other Defenses (cont’d. ) • Macrophages – Engulf and digest antigen – Present then to T cell for recognition © 2010 Delmar, Cengage Learning 28

Cells of the Immune Response and Other Defenses (cont’d. ) • Lymphokines: chemicals released by sensitized T cells • Monokines: chemicals released by activated macrophages • Skin: mechanical barrier – Acid mantle, sebum • Lysozyme: (tears and saliva) attacks bacteria © 2010 Delmar, Cengage Learning 29

Cells of the Immune Response and Other Defenses (cont’d. ) • Mucous membranes: trap microorganisms and debris • Hydrochloric acid: (stomach) destroys microorganisms © 2010 Delmar, Cengage Learning 30

Animation – Lymphatic System • [Insert Lymph. swf] © 2010 Delmar, Cengage Learning 31

Summary • Discussed the functions of the immune system • Described lymph and its flow through the body • Discussed the functions of the spleen and tonsils • Described the different types of immunity • Discussed the immune response © 2010 Delmar, Cengage Learning 32