Presentation on theme: "Functions of the Immune System To protect the entire body from a variety of harmful substances pathogenic microorganisms allergens toxins malignant."— Presentation transcript:
Functions of the Immune System To protect the entire body from a variety of harmful substances pathogenic microorganisms allergens toxins malignant cells
Antigen-Antibody Reactions Antigen - any substance that the body regards as foreign (virus, bacterium, toxin) Antibody - a disease fighting protein developed by the body in response to the presence of an antigen
Structures of the Immune System Not contained in a single system Action depends on structures from lymphatic, cardiovascular, and Integumentary systems Works primarily through antigen-antibody reaction
Check for Understanding 1.What other body systems work with the immune system? How do they work together? Hint* Think back to the past units. 2.What are all the different vocabulary words that mean viruses, bacteria and fungus?
External Defenses Intact skin and mucous membranes Form physical barriers that stop the entry of pathogens Certain cells of the mucous membranes produce mucus A viscous fluid that traps microbes and other particles
Body’s Defenses In the trachea, ciliated epithelial cells Sweep mucus and any entrapped microbes upward, preventing the microbes from entering the lungs Figure m
Secretions of the skin and mucous membranesSecretions of the skin and mucous membranes Provide an environment that is often hostile to microbesProvide an environment that is often hostile to microbes Secretions from the skinSecretions from the skin Give the skin a pH between 3 and 5, which is acidic enough to prevent colonization of many microbesGive the skin a pH between 3 and 5, which is acidic enough to prevent colonization of many microbes Also include lysosymes, that digests the cell walls of many bacteriaAlso include lysosymes, that digests the cell walls of many bacteria
Check for Understanding 1.What is the trachea? Where is it located? 2.What is an epithelial cell? 3. What is a lysosome? Where is it found? Why would skin cells need them more? Hint* Think back to the cell unit. 4.If your body is fighting a war against pathogens, why is it smart to put defenses where it did? Where are they placed? Why is that strategic?
Immunity Immunity- state of being resistant or not susceptible to a specific disease
Natural At birth, inherited and permanent. Includes: Unbroken skin Mucus and tears Blood phagocytes Local inflammation Acquired Body’s reaction to invaders Passive Acquired Active Acquired
Acquired Immunity Passive Acquired Injecting antibodies (not patients) to fight a disease Mother to newborn Active Acquired Natural types are people recovering from a disease and can’t get it again Artificial types are vaccines
Check for Understanding 1.What is the difference between injecting antibodies and injecting a vaccine? How does your body respond differently?
WBCs for Immune Reactions Monocytes - formed in bone marrow/transported where needed by body become macrophages Macrophage - phagocytic cell that protects body by ingesting invading cells Lymphocytes - major class of WBCs formed in lymphatic tissue Figure m3m3m3m
Where Immune Cells come from
Macrophage Large numbers are released during infections Large numbers are released during infections Short lived – die after digesting bacteria Short lived – die after digesting bacteria Found in the organs, not the blood. Made in bone marrow as monocytes, called macrophages once they reach organs. Initiate immune responses as they display antigens from the pathogens to the lymphocytes.
Phagocytosis Process of engulfing and destroying cells.
Lymphocytes T cells or T Lymphocytes mature in thymus gland Cell mediated immunity B cells or B Lymphocytes mature in bone marrow antibody-mediated immunity
Check for Understanding 1.What is the relationship between monocytes and macrophages? 2.What is the relationship between Lymphocytes, B-Cells and T-Cells? 3.Where are macrophages found? 4.Where are B-Cells found? 5.Where are T-Cells found?
T Cell or T Lymphocyte T Cell (cell mediated immunity) Helper T-cells The Helper T-cells coordinate the attack. Killer T-cells Killer T-cells do the work of destroying the infected cells.
B-Cells There are 10 million different B- lymphocytes, each of which make a different antibody. PLASMA CELLSome activated B cells become PLASMA CELL. Plasma cells produce antibodies ~1000/sec
Antibodies Antibodies don’t attack viruses. Antibodies attach to viruses, and bring them in clumps to macrophage.
B-Cells Other Roles Some activated B cells MEMORY CELLS. Memory cells divide rapidly as soon as the antigen is reintroduced. When the pathogen/infection infects again it is destroyed before any symptoms show.
Check for Understanding 1.What is the relationship between antibodies and macrophages? 2.Where do antibodies come from? 3.How many T-Cells are there and what are their individual jobs? 4.Why are B-Cells so special that they are called “morphing” cells?
Major events in the local inflammatory response Figure 43.6 Pathogen Pin Macrophage Chemical signals Capillary Phagocytic cells Red blood cell Bloodclottingelements Blood clot Phagocytosis Fluid, antimicrobial proteins, and clotting elements move from the blood to the site. Clotting begins. 2 Chemical signals released by activated macrophages and mast cells at the injury site cause nearby capillaries to widen and become more permeable. 1 Chemokines released by various kinds of cells attract more phagocytic cells from the blood to the injury site. 3 Neutrophils and macrophages phagocytose pathogens and cell debris at the site, and the tissue heals. tissue heals. 4
Function of Lymphatic System Returns excess interstitial fluid (from tissues) to circulatory system Absorption of fat and fat soluble vitamins from GI system Defense against invading pathogens and disease
Lymphatic System Major structures lymph vessels lymph nodes lymph fluid Tonsils Lymphatic trunks Collecting ducts Also spleen thymus
Lymph System Fluid in lymphatic capillaries are called “lymph” Lymphatic vessels are like blood veins with valves Lymph nodes are specialized organs
Lymph Nodes located in lymph vessels small round or oval structures (filters) depositories for cellular debris bacteria and debris phagocytized Swollen if bacteria is overwhelming
Check for Understanding 1.Glue the lymph model in your notebook and label all major lymph nodes and clusters. 2.Why are lymph nodes so important? 3.Why are lymph vessels and the cardiovascular system so closely connected?
Spleen Sac-like mass of lymphatic tissue filter for blood from lymph Phagocytic cells (macrophages) used to destroy bacteria and toxins
Thymus Primary role: matures T cells T cell development: cells migrate from bone marrow and differentiate into T cells Thymus gets progressively smaller (and less active) through life
Tonsils Used to catch pathogens before they are swallowed into the GI tract. any or all may become so loaded with bacteria that the pathogens gain dominance. Should not be removed unless absolutely necessary
Lymph Carry proteins back into blood Absorb dietary fats Transport pathogens to lymph nodes to be destroyed Maintain balance of pressure in tissue fluid
Exercise is important Lymphatic vessels are not muscles Need physical exercise to contract and push lymph through vessels Squeezing vessels cause flow to go into collecting ducts
Check for Understanding 1.Why do elderly people get sick more often than young adults? Give specific examples and reference specific organs. 2.What immune cells are found in the bone marrow? Hint* Look through all your notes. 3.What immune cells are found in the Thymus? 4.How are blood vessels and lymph vessels different? 5.Why do people say that exercise and health go together?
Acquired Immune Deficiency Syndrome (AIDS) Caused by HIV (Human Immunodeficiency Virus) HIV infects T-helper cells with often a long incubation of up to 10 years AIDS name applied during advanced stages of disease After immune system destroyed, opportunistic infections occur.
Autoimmune Disorders Antigens stimulate development of antibodies that are unable to distinguish antigens of internal cells. Body makes antibodies and T cells against itself and attacks own tissues. Multisystemic involvement. Myasthenia gravis, rheumatoid arthritis
Edema Hypoproteinemia lowers osmotic pressure within blood large amounts of plasma pass out of blood poor lymph drainage increased capillary permeability congestive heart failure localized edema, ascites
Hemophilia Hereditary blood clotting disorder sex-linked, usually in men lack factor VIII, essential for blood clotting hematomas hemarthrosis
Oncology, the study of tumors Metastasis, Metastasize Carcinoma Malignant Melanoma Adenocarcinoma Sarcoma (arises from bone, fat, muscle, etc.) Osteocarcoma Osteosarcoma Myosarcoma Myeloma
Leukemia Major oncological disorder of blood-forming organs Monocytes develop quickly in to B or T cells but do not die Cancerous B or T cells overcrowd the body and organs until other cells can’t function normally
Hodgkin’s Disease Malignant disorder- Cancer cells can spread Cancerous B cells begin to form and grow abnormally large Painless, progressive enlargement of lymph tissue Anorexia, weight loss, anemia
Kaposi’s Sarcoma Malignancy associated with AIDS lesions emerge as purplish-brown macules and develop into plaques and nodules