Body Defense Blood Lymph Membranes Immunity Blood Cells

Body Defense Blood, Lymph, Membranes, Immunity

Blood Cells • RBC: – erythrocytes-erythropoiesis • WBC: – leukocytes - leukopoiesis • Platelets: – thrombocytes thrombopoiesis

Erythrocytes • erythr/o - red • cyte - cell • Hemoglobin - blood protein transports oxygen • Reticulocyte - immature erythrocyte • RBCs produced by red bone marrow

Leukocytes • • • leuk/o - white Protect the body against invasion Pass through capillary walls Granulocytes – neutrophils (phagocytosis) – eosinophils (allergies) – basophils (promote inflammation) Agranulocytes – lymphocytes (production of circulating antibodies) – monocytes (macrophages) Collection of dead and living bacteria and leukocytes called pus, abscess.

Thrombocytes • smallest formed element • made in bone marrow • essential to blood coagulation • If injury, blood comes in contact with any tissue other than the lining of the vessels, platelets stick together, form plug, seals wound. Chemicals released, series of reactions, formation of clot.

Plasma • plasma – 92% water – 8% plasma proteins • albumin • globulin • fibrinogen • serum - plasma without clotting proteins or fibrinogen

Functions of the Immune System • To protect the entire body from a variety of harmful substances – pathogenic microorganisms – allergens – toxins – malignant cells

Structures of the Immune System • Unlike other body systems, Immune System is NOT contained within a single set of organs or vessels • Action depends on structures from lymphatic, cardiovascular, and Integumentary systems • Works primarily through antigen-antibody reaction

Lymphatic System • Major structures – – lymph vessels lymph nodes lymph fluid tonsils • Also – spleen – thymus

Functions of the Lymph System • lymph/o • drain fluid from tissue spaces and return to it to the blood • transport materials (nutrients, hormones and oxygen) to body cells • carry away waste products to the blood • transport lipids away from digestive system • control of infection

Lymph System • Lymph originates in blood plasma • Interstitial fluid • cleans and nourishes body tissues • collects cellular debris, bacteria • return to blood or lymph capillaries

Lymph Nodes • located in lymph vessels • small round or oval structures (filters) • depositories for cellular debris • bacteria and debris phagocytized

Lymph Nodes • inside are masses of tissue which contain WBCs (lymphocytes) • almost always grouped 2 or 3 to 100 • invading cells destroyed in nodes and often swell as an indicator of the disease process

Spleen • sac-like mass of lymphatic tissue • filter for lymph • phagocytic cells • hemolytic

Thymus • lymphatic tissue • mediastinum • primary role: changes lymphocytes to T cells for cellular immunity

Tonsils • masses of lymph tissue designed to filter tissue fluid, not lymph • located beneath certain areas of moist epithelium exposed to outside and hence to contamination • any or all may become so loaded with bacteria that the pathogens gain dominance • should not be removed unless absolutely necessary.

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 • Antigen-antibody reaction or immune reaction

WBCs for Immune Reactions • monocytes - type of lymphocytes – 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

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

T Cell or T Lymphocyte (Cell Mediated Immunity) • T Cell (cell mediated immunity) – circulating lymphocytes – produced in bone marrow – matures in thymus – live for years – primary function: coordinate immune defenses and kill organisms

Lymphocyte: T Cells • helper T cells - essential to proper functioning of immune system • Memory cells- remember antigens and stimulate a faster response if same antigen introduced at a later time

Blood Groups • Four blood groups based on presence or absence of blood antigens (agglutinogens) on surface of RBCs • A - A antigen • B - B antigen • AB - both AB antigens • O - no AB antigens

• Plasma does not contain the antibody against own antigen • Antigens on the donor’s RBCs react with the antibodies in patients plasma and cause a transfustion reaction.

Rh Factor • Rh factor is antigen present on RBC of 85% of pop. of US. • Rh positive and Rh negative • Rh neg pregnant woman may develop antibodies to the Rh protein of her Rh-positive fetus. • hemolytic disease of the newborn • prevented with Rho. GAM

Immunity • Immunity-state of being resistant or not susceptible to a specific disease • Acquired immunity-any form of immunity NOT present at birth and obtained during life

Factors That Influence Immune System • Health • Age • Heredity

Disorders

Anemias • • • Oxygen-carrying capacity of blood is reduced symptom of disease erythropenia hypochromasia hematocrit

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

Infectious Mononucleosis • Acute infection caused by virus. • Fever, sore throat, swollen lymph glands, atypical lymphocytes, splenomegaly, hepatomegaly, abnormal liver function, and bruising. • transmitted by droplet infection • Infection confers permanent immunity • Treatment symptomatic

Oncology, the study of tumors • Metastasis, Metastasize • Carcinoma – Malignant Melanoma – Adenocarcinoma • Sarcoma (arises from bone, fat, muscle, etc. ) – Osteocarcoma – Osteosarcoma – Myeloma

Leukemia • Major oncological disorder of blood-forming organs • malignant cells replace health bone marrow cells • acute myelogenous leukemia • acute lymphocytic leukemia

Hodgkin’s Disease • Malignant disorder • Painless, progressive enlargement of lymphoid tissue first evident in cervical lymph nodes; splenomegaly • Anorexia, weight loss, pruritus, anemia, leukocytosis

Kaposi’s Sarcoma • Malignancy associated with AIDS • lesions emerge as purplish-brown macules and develop into plaques and nodules