ch. 12 lymphatic system immunity

1. Ch. 12 Lymphatic System & Immunity Lymph – fluid in tissue spaces that carries protein molecules and other substances back to the blood Lymphatic vessels Capillaries Microscopic 1 cell layer Porous walls Called lacteals in intestinal wall

2. Ch. 12 Lymphatic System & Immunity Right lymphatic duct Drains lymph from upper right extremity, head, neck and upper torso.

3. Ch. 12 Lymphatic System & Immunity Thoracic Duct Largest Has enlarged pouch called cisterna chyli Drains ¾ of the body

4. Ch. 12 Lymphatic System & Immunity Lymph nodes Filters lymph In clusters Defense and WBC formation Flow of lymph afferent to node via several vessels, out of one efferent vessel

5. Ch. 12 Lymphatic System & Immunity Thymus Organ located in mediastinum. Weighs less than an ounce (35-40 grams) Central role in immunity Produces T-lymphocytes (T-Cells) Secretes hormones called thymosins

6. Ch. 12 Lymphatic System & Immunity Tonsils 3 masses of lymphoid tissue Palatine tonsils (“the tonsils”) Pharyngeal tonsils (adenoids) Lingual tonsils Subject to infection Enlargement may impair breathing

7. Ch. 12 Lymphatic System & Immunity Tonsils and Adenoids

8. Ch. 12 Lymphatic System & Immunity Spleen Largest lymphoid organ in the body In upper left quadrant of abdomen Removal called splenectomy Functions: Phagocytosis of bacteria Phagocytosis of RBC’s Acts as a blood reservoir

9. Ch. 12 Lymphatic System & Immunity The Immune System Protects body from pathological bacteria, foreign tissue cells, and cancerous cells Made of specialized cells and molecules Non-specific immunity Skin Tears and mucous Inflammation

10. Ch. 12 Lymphatic System & Immunity Specific immunity Ability if body to recognize and remember harmful substances

11. Ch. 12 Lymphatic System & Immunity Inherited or inborn immunity – immune to some diseases from birth Acquired immunity Natural active – active disease produces immunity Natural passive – immunity passing from mother Artificial active – vaccination results in immunity Artificial passive – antibodies from another individual

12. Ch. 12 Lymphatic System & Immunity Immune system molecules Antibodies Protein compounds with specific combining sites Attach to specific antigens Antigen-antibody complexes: Neutralize toxins Agglutinate enemy cells Promotes Phagocytosis

13. Ch. 12 Lymphatic System & Immunity Complement proteins 14 proteins in the blood are in an inactive state Compliment fixation Mechanism of action for antibodies Causes cell lysis by permitting entry of water through defect created in plasma membrane.

14. Ch. 12 Lymphatic System & Immunity Immune system cells Phagocytes ingest and destroy foreign cells or harmful substances Neutrophils Monocytes Macrophages Kupffer’s cells (liver) Dust cells (lungs)

15. Ch. 12 Lymphatic System & Immunity Lymphocytes Most numerous immune system cells Development of B cells – primitive stem cells migrate from bone marrow through 2 stages of development. 1st stage – stem cells develop into immature B cells 2nd stage – immature B cell develops into activated B cells. Divides into clones repeatedly, to form memory cells and plasma cells. Plasma cells secrete antibodies and memory cells are stored in the lymph nodes. Memory cells will produce plasma cells when activated.

16. Ch. 12 Lymphatic System & Immunity Function of B cells Indirectly – B cells produce humoral immunity. Activated B cells develop into plasma cells. Plasma cells secrete antibodies into the blood. Circulating antibodies produce humoral immunity.

17. Ch. 12 Lymphatic System & Immunity Development of T –cells stem cells from bone marrow migrates to the thymus gland. Stage 1 – stem cells develop into T cells. Occurs in thymus right before and after birth. T cells migrate to lymph nodes. Stage 2 – T cells develop into sensitized T cells, occurs when antigen binds to the T cell’s surface.

18. Ch. 12 Lymphatic System & Immunity Function of T Cells Produces cell mediated immunity Kills invading cells by releasing a toxin that kills the invader. The releasing chemicals attract and activate macrophages to kill cells by Phagocytosis.