Anatomy and Physiology With Pathophysiology PDF

ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY Module 8 Lymphatics Capillaries in Tissue 3. Defense. Spacies  Microorganisms filtered from lymph-by-lymph nodes and from...

ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY Module 8 Lymphatics Capillaries in Tissue 3. Defense. Spacies  Microorganisms filtered from lymph-by-lymph nodes and from blood by the spleen lymph to remove pathogens, many infectious diseases produce symptoms associated with the lymphatic system Lymphatic System and Immunity FUNCTIONS OF THE LYMPHATIC SYSTEM 1. Maintenance of fluid balance  30 liters (L) of fluid pass from the Lymph Formation and blood capillaries into the Movement interstitial spaces each day  27 L pass from the interstitial spaces back into the blood a. Fluid moves from blood capillaries capillaries into tissues and from  3 L of fluid enters the lymphatic tissues into lymphatic capillaries - Will not be absorbed capillaries to form lymph. b. The overlap of epithelial cells of → edema ➔ tissue damage the lymphatic capillary allows 2. Lipid absorption fluid to enter easily but prevents  absorbs lipids and other it from moving back into the substances from the digestive tissue. Valves, located farther tract through lymphatic vessels along in lymphatic vessels, also called lacteals located in the lining ensure one-way flow of lymph. of the small intestine. Lacteals → lymphatic vessels →venous circulation  Lymph passing through these lymphatic vessels appears white because of its lipid content and is called chyle  3 factors cause compression of the lymphatic vessels: 1. contraction of surrounding skeletal muscle during activity 2. periodic contraction of smooth muscle in the lymphatic vessel wall Direction of lymph flow in capillary 3. pressure changes in the thorax during breathing. Lymphatic capillaries are present in most tissues of the body. Exceptions are the central nervous system, bone marrow, and tissues lacking blood vessels, such as the epidermis and cartilage FLOW OF LYMPH IN LYMPHATIC VESSELS 1. LYMPHATIC CAPILLARIES  thin-walled channels, which collect excess interstitial fluid from the tissue spaces as lymph and return it to the blood 3. Lymphatic vessels from the right  NO VALVE upper limb and the right half of the head, neck, and chest form the right  all tissues have lymphatics lymphatic duct, which empties into the except right subclavian vein. a) central nervous system, b) bone marrow 4. Lymphatic vessels from the rest of c) tissues lacking blood the body enter the thoracic duct, which vessels, such as the empties into the left subclavian vein. epidermis and cartilage  they converge to form Summary of Flow: 2. LYMPHATIC VESSELS  lymphatic capillaries  resemble small veins  lymphatic vessels  beaded appearance because  lymph nodes they have one-way valves that  lymphatic vessels are similar to the valves of  R-side: Lymphatic duct veins L-side: Thoracic duct  if compressed, the valves  Subclavian vein prevent backward movement of  SVC Superior vena cava lymph  Heart  lymphatic vessels converge and eventually empty into the blood at two locations in the body.  Lymphatic Organs 1. tonsils, 2. lymph nodes 3. spleen 4. thymus Lymphatic tissue is characterized by housing many lymphocytes and other defense cells, such as macrophages. 1. Tonsils  There are three groups of tonsils a. paired palatine tonsils o located on each side of the posterior opening of the oral Parts of the Lymph cavity; these are the ones Node: usually referred to as “the 1. A dense connective tissue tonsils.” capsule surrounds each lymph b. pharyngeal tonsils node o located near the internal 2. Extensions of the capsule, opening of the nasal cavity. called trabeculae, subdivide a o When the pharyngeal tonsil is lymph node into compartments enlarged, called the adenoid containing lymphatic tissue and o An enlarged pharyngeal lymphatic sinuses. tonsil can interfere with 3. The lymphatic tissue consists of normal breathing lymphocytes and other cells c. lingual tonsil that can form dense o is on the posterior aggregations of tissue called surface of the tongue. lymphatic nodules. 2. Lymph Nodes Note that lymphatic  rounded structures that vary in size nodules are not the same  located near lymphatic vessels as lymph nodes.  lymph passes through lymph nodes 4. Lymphatic nodules containing before entering blood the rapidly dividing lymphocytes are called germinal centers. 3 superficial aggregations of 5. Lymphatic sinuses are lymph nodes on each side of the spaces between the lymphatic body: tissue that contain 1. inguinal nodes in the groin macrophages on a network of 2. the axillary nodes in the axilla fibers. (armpit) 3. the cervical nodes in the neck. The Spleen Thymus  spleen filters blood instead of  thymus is the site for the lymph maturation of a class of  capsule of dense connective lymphocytes called T cells tissue and a small amount of  bilobed gland roughly smooth muscle. triangular in shape  Trabeculae from the capsule  located in the superior divide the spleen into small, mediastinum, the partition interconnected compartments dividing the thoracic cavity containing two specialized into left and right parts. types of lymphatic tissue:  Each lobe of the thymus is 1. White pulp surrounded by a thin  surrounding the connective tissue capsule. arteries  Trabeculae from the 2. Red pulp capsule divide each lobe  associated with the into lobules veins  Near the capsule and  filled with trabeculae, lymphocytes macrophages and are numerous and form red blood cells, and dark-staining areas called enlarged capillaries the cortex. that connect to the  A lighter-staining, central veins. portion of the lobules, called the medulla, has fewer lymphocytes.  Overview of the Lymphatic System 1. Lymphatic capillaries and vessels remove fluid from tissues 2. Lymph flows to lymphatic vessels that have valves to prevent backflow 3. Lymph filtered by the lymph nodes then flows into the lymphatic vessels 4. R side of the body (upper extremity only) flows to the lymphatic duct L: side flows to the Thoracic duct 5. Goes into the subclavian vein → SVC → heart 6. Specialized lymphatic vessels called lacteals absorb lipids at the small intestine. The lymph in these vessels is IMMUNITY referred to as chyle due to the high lipid content Immunity 7. Lymph flows into the thoracic duct  is the ability to resist damage → subclavian vein → SVC →heart from foreign substances. 8. The spleen filters blood and is a site  can protect against microbes, where lymphocytes respond to toxins, and cancer cells. infections. 9. Pre-T cells are produced in red Types of immunity: bone marrow and migrate to the thymus, where they mature to A. INNATE Immunity become T cells  present at birth 10. B cells, which are produced and  defense against any pathogen mature in the red bone marrow, and T  accomplished by: cells from the thymus circulate to, and 1. physical barriers- Skin and populate, other lymphatic tissues. mucous membranes to act as barriers 2. chemical mediators a. Lysozyme: found in tears and saliva to kill bacteria b. Mucous membranes: prevent entry of microbes c. Histamine: promote inflammation by causing vasodilation d. Interferons: proteins that protect against viral infections by stimulating surrounding cells to  produce antiviral  This immunity: proteins.  is acquired after birth 3. Cells: WBC  reacts when innate a. Neutrophils: first to defenses don’t work respond to infection but  slower than innate die quickly immunity  Secretion of cellular  has memory toxins, which affect  uses lymphocytes (B them in the same and T cells) way they affect  2 types: antibody- pathogens mediated and cell- b. Eosinophils: release mediated chemicals to reduce inflammation Terms Related to Adaptive Immunity c. Basophils: leave blood and enter infected Antigen: tissues can release  substance that stimulates an histamine immune response Example— d. Macrophages: bacteria, virus, pollen, food, initially were monocytes drugs → leave blood and enter tissues - antigen- Self-antigen: presenting→ secretes  molecule produced by the interleukins →activates person’s body that stimulates ThCells an immune system response  Kupffer cells in liver  Langerhans cells: Antibody: skin  proteins the body produces in  Osteoclast: bones response to an antigen e. Mast cells: can release leukotrienes f. Natural Killer Cells:  recognize classes of cells such as tumor cells or virus infected cells  release chemicals to lysis cells 4. inflammatory response - stimulates release of chemical mediators B. ADAPTIVE Immunity Adaptive immunity  is defense that involves specific recognition to a specific antigen.  Origin and Development of Lymphocytes Stem cells:  red bone marrow  give rise to all blood cells  give rise to some pre-T cells and pre-B cells B cells:  involved in antibody-mediated immunity  originate from stem cells  mature in red bone marrow  move to lymphatic tissue after mature  lead to production: of 1. Antibodies T cells:  involved in cell-mediated immunity primarily and antibody-mediated immunity  mature in thymus gland  move to lymphatic tissue after mature 4 types: 1. T-helper (CD4  help form B cells 2. T-cytotoxic (CD8+)  destroys antigen on contact Antigen Recognition 3. T-regulatory  turn off immune  Lymphocytes have antigen system response receptors on their surface when antigen is called B-cell receptors on B gone cells and T-cell receptors on T 4. Natural killer cells cells  (NK cells)  Each receptor only binds with a specific antigen Adaptive immunity can be divided  When antigen receptors into: combine with the antigen, the  antibody-mediated immunity lymphocyte is activated and  cell-mediated immunity adaptive immunity begins. The MHC Molecule The major histocompatibility complex molecule (MHC):  contain binding sites for antigens  specific for certain antigens  hold and present a processed antigen on the surface of the cell membrane  bind to antigen receptor on B or T cells and stimulate response. Antibody-Mediated Immunity: B- cells Antibodies are proteins produced in Cytokines response to an antigen.  proteins secreted by a cell that regulates neighboring cells  Example—interleukin 1 released by macrophages stimulates helper T cells.  Active immunity  results when an individual is exposed to an antigen (either naturally or artificially) and the response of the individual’s own immune system is the cause of the immunity. Passive immunity  occurs when another person or an animal develops immunity and the immunity is transferred to a nonimmune individual. Natural and artificial refer to the method of exposure or antibody transfer. Natural  contact with the antigen or transfer of antibodies occurs as part of everyday living and is not deliberate Artificial  implies that deliberate introduction of an antigen or antibody into the body has occurred Active Natural Immunity  natural exposure to an antigen, such as a disease-causing microorganism  Ex: chickenpox acquired thru infected sister → Ab IMMUNOLOGY: ACQUIRED IMMUNITY Active Artificial Immunity  antigen is deliberately Antibodies are proteins produced in introduced to individual to response to an antigen stimulate the immune system  Ex: Vaccination against 4 ways to acquire adaptive chickenpox DPT (diphtheria, immunity: Antibody tetanus, pertussis) MMR 1. active natural (mumps, measles, rubella) 2. active artificial 3. passive natural 4. passive artificial Passive Natural Immunity  antibodies are transferred from a mother to her child across the placenta before birth  Ex: mother have HepaB antibodies → baby breastmilk: contains IgA → baby Passive Artificial Immunity  antibodies from one source and introducing them to an infected individual, usually through injection (ANTISERA)  Ex: rabies, hepatitis, and measles; bacterial toxins (tetanus, diphtheria, and botulism); and venoms from certain snakes and spiders. Ways to Acquire Adaptive Immunity