Unit 8. Lymphatic System and Immunity PDF

LYMPHATIC SYSTEM https://www.youtube.com/watch?v=cCPyWFK0IKs&t=5s https://www.youtube.com/watch?v=JRkLDKrDtDY Functions of the Lymphatic system 1. Fluid Balance. The lymphatic system is a network of lymphatic vessels and lymph nodes present in the different area of the body that maintains home...

LYMPHATIC SYSTEM https://www.youtube.com/watch?v=cCPyWFK0IKs&t=5s https://www.youtube.com/watch?v=JRkLDKrDtDY Functions of the Lymphatic system 1. Fluid Balance. The lymphatic system is a network of lymphatic vessels and lymph nodes present in the different area of the body that maintains homeostasis as well as immunity of the body. 30L of fluid pass 27L pass from the from the blood interstitial spaces capillaries into the back into the blood interstitial spaces capillaries. each day The remaining fluid enters the lymphatic capillaries, where the fluid is called lymph.  If the extra 3L of interstitial fluid remained in the interstitial spaces, edema would result, causing tissue damage. 2. Lipid absorption Absorbs fats from the digestive tract. Lymph includes fluids from the intestines that contain fats and proteins and transports it back to the bloodstream. Lacteals are lymphatic vessels located in the lining of the digestive tract. The lymphatic system absorbs lipids and other substances from the digestive tract through the lacteals. Fat Digestion and Absorption Fat digestion and absorption begins The salivary gland slowly with some releases, lingual fats melting at lipase, an enzymes body temperature which has active role in the mouth. in fat digestion. The presence of gastric contents Muscle contraction stimulate the move stomach release of gastric contents, breaking up lipase enzyme and the fat into small fat is further pieces or droplets. digested In the SI, the gallbladder releases bile acids In the LI, bile that is with phospholipids trapped by dietary for further fibers (parts of emulsification. foods the body can't digest or The breakdown of large fat absorb) exits the molecules into small fat droplets body through elimination. 3. Defense. Protects your body against foreign invaders. The lymphatic system produces and releases lymphocytes (white blood cells) and other immune cells that monitor and destroy the foreign invaders — such as bacteria, viruses, parasites and fungi that may enter in the body. https://www.youtube.com/watch?v=Q84-mP0cGWQ 4. Transport and removes waste products and abnormal cells from the lymph. The Lymphatic System consists of the following: 1. Lymph – is a clear watery fluid that circulates through the lymphatic system; also called lymphatic fluid, a collection of the extra fluid that drains from cells and tissues in your body and isn't reabsorbed into your capillaries. Lymph contains many different substances, including proteins, minerals, fats, damaged cells, cancer cells and germs. 2. Lymph nodes - are small, bean-shaped organ that serves as filtering and processing immune system Approximately 450 lymph nodes are distributed throughout the body: Cervical and head lymph nodes (about 70) filter lymph from the head and neck. Axillary lymph nodes (about 30) filter lymph from the upper limbs and superficial thorax. Thoracic lymph nodes (about 100) filter lymph from the thoracic wall and organs. Abdominopelvic lymph nodes (about 230) filter lymph from the abdomen and pelvis. Inguinal and popliteal lymph nodes (about 20) filter lymph from the lower limbs and the superficial pelvis. What is the inside of a lymph node? Lymph nodes or lymph glands) are small lumps of tissue that contain WBCs, which fight infection. Afferent lymphatic vessels flow into a lymph node and carry unfiltered lymph fluid. Efferent lymphatic vessels flow out of a lymph node and carry filtered lymph fluid. The body of the lymph node is divided into an outer cortex and an inner medulla. The cortex contains a high concentration of lymphocytes while the inner medulla is less cellular. 3. Lymphatic vessel Transport the lymph from interstitial fluid, back into the blood. The lymphatic vessels converge to form larger vessels called lymphatic trunks, each of which drains lymph from a major portion of the body. The valves is to prevent backflow of fluid, so that lymph eventually flows forward instead off falling backwards. 4. Other lymphoid organs 4.1 Spleen The SPLEEN has several functions, including: destroying defective red blood cells, detecting and responding to foreign substances in the blood acting as a blood reservoir 4.2 Thymus gland The thymus is the site for the maturation of T cells. Thymosin, a hormone secreted by the thymus, is important in the T-cell maturation process. 4.3 Tonsils Traps and removes any bacteria or other foreign pathogens entering the throat. They act as a front-line defense forming the initial immunological response to inhaled or ingested pathogens. TONSILLECTOMY 4.4 Peyer’s Patches Are small mass of lymphatic tissues found in the ileum of the small intestine. These capture and destroy bacteria, thereby preventing microbes from penetrating the intestinal wall. 4.5 Red bone marrow – site where lymphocytes originate 4.6 Appendix Contains lymphoid tissue that can destroy bacteria before it breaches the intestine wall during absorption. It is also said to produce early defenses that help prevent serious infections in humans. IMMUNITY Immunity IMMUNITY IS CATEGORIZED AS: INNATE AND ADAPTIVE IMMUNITY 1) INNATE IMMUNITY also called nonspecific resistance the body recognizes and destroys certain foreign substances, but the response to them is the same each time the body is exposed. includes body defenses that are present at birth and genetically determined. each time the body is exposed to a substance, the response is the same because specificity and memory of previous encounters do not apply. Main components of INNATE IMMUNITY are: 1) Physical Barriers - physical barriers that prevent microbes from entering the body or that physically remove them from body surfaces; such as the skin and mucous membranes; tears; saliva; urine 2) Chemical Mediators - are molecules responsible for many aspects of innate immunity; Some chemical mediators on the surface of cells kill microorganisms or prevent them from entering the cells Immunity is categorized as: 2) ADAPTIVE IMMUNITY also called specific immunity the body recognizes and destroys foreign substances, but the response to them is faster and stronger than the first time the foreign substance was encountered. includes body defenses that are acquired through a person’s lifetime, depending on exposure to different microorganisms. the response during the second exposure is faster and stronger than the response to the first exposure because the immune system “remembers” the bacteria from the first exposure ADAPTIVE IMMUNITY is the ability of lymphocytes to recognize, respond to, and “remember” a particular substance ANTIGEN - substances that stimulate adaptive immunity; are usually large molecules with a molecular weight of 10,000 or more. Adaptive immunity involves two major types of lymphocytes: B cells and T cells, each of which carries out defense of the body in different ways Adaptive immunity can be broken down into four types based on the way it is acquired: (1) active natural (2) active artificial (3) passive natural (4) passive artificial Active immunity results when an individual is exposed to an antigen (either naturally or artificially) and the response of the individual’s 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. Natural exposure implies that contact with an antigen or antibody occurs as part of everyday living and is not deliberate. Artificial exposure, also called immunization, is the deliberate introduction of an antigen or antibody into the body. 1 2 3 4 Antibodies are protective proteins produced by the immune system. They attach to antigens (foreign substances) — such as bacteria, fungi, viruses and toxins — and remove them from the body. Immunoglobulins, also known as antibodies, are glycoprotein molecules produced by plasma cells (white blood cells).  Antibody Type Function IgA Found in saliva, tears, mucus, breast milk and intestinal fluid. IgA protects against Dimer ingested and inhaled pathogens.  Antibody Type Function IgD This antibody is found on the surface of the B cells. Induce antibody production and the prevention of respiratory tract infections. Monomer  Antibody Type Function IgE Found mainly in the skin, lungs and mucus membranes, IgE antibodies cause your mast cells to release Monomer histamine.  Antibody Type Function IgE IgE antibodies are helpful for fighting off allergic reactions. Monomer  Antibody Type Function IgG Most common antibody, making up approximately 70% to 75% of all immunoglobulins. Found in blood and tissue fluids. Help protect body from Monomer viral and bacterial infections.  Antibody Type Function IgM Found in blood and lymph system. IgM antibodies act as the first line of defense against infections. They also play a Pentamer large role in immune regulation. Common immunoglobulins include the Hepatitis B immune globulin, administered to clients after exposure to the hepatitis B virus; Tetanus immunoglobulin, or TIG, for prophylaxis of tetanus infection in clients with traumatic, puncture, or contaminated wounds; Botulism immune globulin, or BIG, treat infant botulism caused by toxin type A or B. https://www.youtube.com/watch?v=qCRwuxDpthY Antigens and Antibodies https://www.youtube.com/watch?v=Bgd1qxQ0Dh4 Antigen Processing and Presentation