Lymphatic and Immune System Flashcards
The lymphatic system is closely connected with what other body system?
Cardiovascular
What are lymphatic vessels?
The lymphatic vessels take up excess tissue fluid and return it to the bloodstream
What are three functions of the lymphatic system?
(1) The lymphatic vessels take up excess tissue fluid and return it to the bloodstream. (2) Lymphatic capillaries absorb fats and transport them to the bloodstream. (3) The lymphatic system helps with immunity to defend the body against disease.
What is lymph
Excess tissue fluid entering the lymphatic capillaries from the interstitial fluid not returned by the cardiovascular system.
Describe the flow of lymph.
The lymph flows one way, from the lymphatic capillary system to the subclavian veins, where it joins the venous circulation to return to the heart.
Describe the structure of lymph vessels.
Lymph vessels have one-way flow valves similar in structure to the large veins of the cardiovascular system. The valves prevent the backward flow of lymph. The return of the lymph fluid into circulation is solely dependent on the squeezing action of skeletal muscles, squeezing the fluid one way through the lymphatic vessels.
Describe the structure of a lymph node.
A lymph node is encapsulated in a fibrous connective tissue with many incoming and fewer outgoing lymphatic vessels. Incoming vessels (afferent vessels) flow through a network of sinuses that contain cells. The lymph then flows out of the lymph node through the efferent vessel. The interior of the lymph node is divided into open spaces called nodules, containing lymphocytes and macrophages.
The spleen is in what region of the body?
The spleen is in the upper left abdomen.
What is the function of the spleen?
The spleen functions to extract old or defective blood cells and platelets. The spleen also removes debris, foreign matter, bacteria, viruses and toxins from the blood that flows through it.
thymus function.
The thymus secretes thymosin and thymopoietin hormones which enable T lymphocytes (T cells) to mature and function as part of the immunity system. Mature T cells attack body cells which are cancerous or infected with pathogens.
tonsils function.
The tonsils gather and destroy bacteria inhaled in air or food.
What is the purpose of the specific immune system?
The specific immune system is targeted and extremely effective against pathogens. The main lymphocytes involved in specific immune responses are the T cells and the B cells.
What is swelling and why does it occur?
Tissue swelling dilates blood vessels in the affected area to help increase the number of immune cells responding to the infection. The increase of blood also causes redness and pain, helping to bring a conscious awareness of the infection
What are the two types of cytokines?
The two main groups of cytokines include interferons and interleukins.
What cells produce cytokines?
Both types of cytokines are produced by a variety of immune cells, including macrophages, T cells, B cells, and fibroblasts.
What is the purpose of interferons?
Interferons inhibit viral replication and assist in activating natural killer cells.
What is the purpose of interleukins?
chemical activators signals in the body to increase the immune response. Activate different types of immune cells.
What are pyrogens?
Pyrogens reset the body’s thermostat in the hypothalamus. create fevers
How does a fever help the body?
Interfering with the growth and replication of pathogens. Fevers also causes lysosomes, an organelle inside cells, to break down
What are the two subtypes of white blood cells?
Agranulocytes and granulocytes
Describe the major purpose of neutrophils.
Neutrophils are responsible for fighting infection (phagocytes)
What are the steps of phagocytosis?
recognizes a pathogen by its cell surface receptors, binds to the pathogen and brings it inside the cell forming a vacuole, vacuole fuses with cell lysosomes which release digestive enzymes to destroy the pathogen. Once the pathogen is destroyed, the contents are released from the cell.
What do eosinophils do
Eosinophils respond to allergic reactions and parasitic infections. (Phagocytes)
What do basophils release?
Histamines and heparin
Monocytes transform into ____ when the migrate into the tissue from the blood.
Macrophages
Describe the structure of a B cell and how it becomes activated.
Each B cell is genetically programmed to produce a glycoprotein receptor as part of its cell coat. Each receptor binds with a specific type of antigen. B cells become activ
What do plasma cells do?
Each plasma cell produces antibodies, which is a soluble form of the glycoprotein receptor from the B cell’s surface. After the antibody is released, it binds to the invading antigen to cause it to be inactive or mark it for destruction.
What are memory B cells?
Some activated B cells become memory B cells which continue to produce a small amount of antibody even after the infection is over. If the same pathogen enters the body again, the antibody immediately binds with the antigen. The memory B cells can produce a specific antibody much faster and targets it for destruction at a much faster rate the second time a pathogen invades the body.
What is antibody mediated immunity?
Antibody-mediated immunity defends the body against pathogens through the secretion of antibodies. The antibodies bind to the pathogen, making it unable to cause further damage in the body and marking it for phagocytosis.
What are the 5 classes of antibodies?
IgG, IgE, IgD, IgM and IgA
What is cell mediated immunity?
Cell mediated immunity releases contents to kill a pathogen, such as cytokines and enzymes. Cell mediated immunity also includes the direct cellu
Describe the structure of T cell membranes.
T cells contain antigen receptors that bind to specific glycoproteins in cell membranes.
What is a killer T cell?
Killer T cells (cytotoxic T cells) recognize and destroy invading cells containing foreign antigens. Killer T cells attack virus-infected cells or cells infected with cancer cells by releasing cytokines and enzymes locally to lyse the cell
What is a helper T cell?
Helper T cells secrete substances that activate or enhance immune responses. B cells require an interaction with helper T cells before they can begin rapid division.
What types of cells do NK cells destroy?
Natural killer cells seek out abnormal body cells and destroy them. This makes NK cells highly effective against tumor cells.
What is the MHC
glycoprotein surface receptors, allows immune system to determine what cells are good
How do Killer T cells use the MHC complex?
recognize and destroy invading cells through this self or not-self recognition of the MHC complexes on each cell
What is an autoimmune disease?
antibodies and T cells attack the body’s own tissues.
What occurs in the disease process of RA?
T cells produce interleukins which cause inflammation inside the joints systemically.
What occurs in the disease process of MS
Antibodies attack the or prevent the formation of the myelin sheath around nerve cells, resulting in muscular weakness.
Hives are_____.
Swelling in the form of raised red bumps
What is anaphylactic shock?
capillaries become so dilated it causes their blood pressure to drop too low, leading to collapse
What is lymphedema
edema where the lymphatic system is not working properly to return fluid back into circulation causing swelling
What is tonsillitis?
infection in tonsils
