THE LYMPHATIC SYSTEM

OBJECTIVES Describe the major functions and structures of the lymphatic system List the primary lymphatic structures Recognize, define, spell, and pronounce the the major terms related to the system Discuss and compare the differences in the immune system

LYMPHATIC SYSTEM STRUCTURE & FUNCTION Substances that cannot enter or return through the capillary walls, including excess fluid and protein molecules are returned to the blood as Lymph Lymph: is a specialized fluid formed in the tissue spaces that is transported by way of specialized lymphatic vessels

LYMPHATIC SYSTEM Mammary Plexus R. Lymphatic Duct Cubital Nodes Popliteal Nodes Cervical Nodes L. Subclavian Axillary Nodes Thoracic Duct Iliac Nodes Inguinal Nodes

Blood plasma filters out of the capillaries into microscopic places between tissues and cells This process takes place because of the pressure generated by the pumping action of the heart HOW LYMPH IS FORMED

LYMPHATIC DRAINAGE OF THE BREAST

INTERSTITIAL FLUID Plasma that flows out of the capillaries of the circulator system Much of this fluid goes back into the blood by the same route it came out - - capillary membrane

LYMPH VESSELS Capillaries: thin-walled tubes that carry lymph fluid from the tissues to the larger lymphatic vessels Have valves that prevent the backward flow of fluid and lymph (Toward thoracic cavity) Right lymphatic duct and thoracic duct empty lymph into veins in the upper thoracic region

LYMPHATIC SYSTEM CAPILLARY BED

Lacteals: specialized lymph capillaries located in the villi of the small intestine -- Fats and fat-soluble vitamins are absorbed and carried to the bloodstream LYMPH VESSELS Cont.

Small bean-shaped structures located in lymph vessels that provide a site for production of lymphocytes LYMPH NODES Filter lymph to remove harmful substances such as bacteria, viruses, and malignant cells

LYMPHNODELYMPHNODE

Saclike mass of lymphatic tissue located in the left upper quadrant of the abdomen, just inferior (below) the diaphragm and posterior (behind) stomach SPLEEN Filters microorganisms and foreign matter from blood Forms lymphocytes and monocytes Removes and destroys Worn-out blood cells -- hemolytic

SPLEEN

THYMUS GLAND Lymphoid tissue found in the mediastinum Critical role in the body’s immunity mechanics Completes most of its work in early childhood Produce T-lymphocytes which play a critical role in the function of the immune system

TONSILS Masses of lymphatic tissue that form a protective ring around the nose and upper throat TONSIL LOCATIONS Adenoids: nasopharynx Palatines: portion of throat visible through the mouth Lingual: base of the tongue

TONSILS

PEYER’S PATCHES Small areas of lymphatic tissue found in the walls of the small intestine VERIFORM APPENDIX Lymphatic tissue that hangs from the lower portion of the cecum of the large intestine

APPENDIX PEYER’S PATCH

THE IMMUNE SYSTEM Function: protects the body from harmful substances including: -- Pathogens (disease-producing) -- Allergens (substances producing allergic reactions) -- Toxins (poisons) -- Malignant cells

State of being resistant or not susceptible to a specific disease IMMUNITY

IMMUNE SYSTEM CELLS Primary cells of the immune system include: PHAGOCYTES -- Neutrophils -- Monocytes -- Macrophages LYMPHOCYTES -- t-LYMPHOCYTES -- b-LYMPHOCYTES

IMMUNITY Antigen: any substance such as a virus, bacterium, or toxin that the body regards as foreign. Antibody: a disease-fighting protein created by the immune system in response to the presence of that specific antigen Immune reaction: also know as antigen-antibody reaction. Binding foreign antigens to antibodies to form antigen-antibody complexes

NONSPECIFIC IMMUNITY Maintained by mechanisms that attack any irritant or abnormal substance that threatens the internal environment Barriers include: skin, mucous membranes, tears Inflammatory response: nonspecific responses that occurs in the body such as heat, redness, swelling, and pain

SPECIFIC IMMUNITY - Specific protection against certain types of invaders - Involves Memory, ability to respond to certain particular harmful substances

Inherited immunity to certain diseases. Common to the human race. INBORN IMMUNITY

Obtained by development of antibodies during attack of an infectious disease ACQUIRED ACTIVE IMMUNITY

Passed from mother to fetus before birth. Immediately after birth, additional immunity is passed from mother to child through breast milk ACQUIRED PASSIVE IMMUNITY

Also known as immunization Immunity that was acquired through vaccines -- Chickenpox-- Mumps -- Hepatitis B-- Measles -- Smallpox -- Meningitis -- Pertussis-- Typhoid May be active or passive ARTIFICIAL IMMUNITY

IMMUNE SYSTEM MOLECULES Functions because of adequate amounts of highly specialized protein molecules and unique cells Made up of antibodies and complements

ANTIBODIES Protein compounds that are normally present in the body Able to combine with a specific compound called an antigen Promote and enhance phagocytosis

Humoral -First bind to a specific antigen -Forms antigen-antibody complex -Neutralize the toxin -May agglutinate the enemy cells -Macrophages “eat” them up.

COMPLIMENTS Group of at least 14 proteins normally present in an inactive state in blood Activated by exposure of complement-binding sites on antibodies The result is an antigen-antibody complex The sequence of events is called compliment fixation

COMPLIMENT FIXATION Antigens that are molecules on an antigenic or foreign cells surface combine with antibody molecules Change the shape of the molecule just enough to expose two previously hidden regions called the compliment-binding sites Exposure initiates a series of events that kill the cell on whose surface they take place

COMPLIMENT FIXATION Kills invading cells of various types Drills hole in the plasma membrane Sodium rapidly infuses the cell Cell literally bursts

COMPLIMENT FIXATION

IMMUNE SYSTEM CELLS Primary cells of the immune system include: PHAGOCYTES -- Neutrophils -- Monocytes -- Macrophages LYMPHOCYTES -- t-LYMPHOCYTES -- b-LYMPHOCYTES

Formed in bone marrow Perform phagocytosis Monocytes/Neutrophils are most important!!! Phagocytes

Migrate into blood and tissues In tissues, monocytes develop into macrophages Phagocytes

Some macrophages wander through tissue and “eat” invaders. Some stay permanent in organs. Macrophages Kupffers Cells- are located in the liver Dust Cells- are located in small air sacs in lungs

Specialized antibodies help macrophages function effectively Macrophages CAN ALSO BE FOUND IN SPLEEN, LYMPH NODES LINING OF THORACIC AND ABDOMINAL CAVITIES

Most numerous immune system cells Ultimately responsible for antibody production Scattered throughout the body’s lymph tissue Act like “Gestapo” Lymphocytes B- Cells and T- Cells

Humoral Immunity- resistance to disease organisms produced by actions of antibodies. (circulating immunity) Function of B Cells

B-CELLS Known as a B-lymphocyte -- Designed to make one specific antibody against a specific antigen -- Very effective against viruses, and bacteria circulating in the blood When confronted with this type of antigen, B cells transformed into plasma cells

Produce and secrete antibodies coded to match the antigen and secrete the antibodies coded to match the antigen. This match enables the body to destroy the antigen in the antigen-antibody response PLASMA CELLS

-Secrete copious amounts of antibodies - Live only a few days - Circulate throughout the body - Antibody factories Plasma Cells

-Memory cells secrete antibodies (not immediately) - Remain in reserve until contacted by the same antigen -Transform to plasma cells Memory Cells

Also known as T-Lymphocytes -- Small circulating lymphocytes -- Matured in the Thymus by exposure to thymosin Primary function is to coordinate immune defense and kill invading organisms on contact T-CELLS

-Cell mediated immunity -Kill invading cells directly -Coordinate immune defenses and kill invading organisms on contact -Release a lethal poison of a bound cell. T- Cells

Produced by the T-cells Proteins released by cells when invaded by a virus Causes noninfected cells to form an antiviral protein that slows or stops viral multiplication INTERFERON

QUESTIONS

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