Lymphatic System and

Immunity

By Melanie E.Alexis C.

Lavinia G.

General FunctionsLymphatic System circulates the lymph fluid throughout

the body

Immunity= Lymph fluid consisting of antibodies and lymphocytes

Fluid and Protein Balance= prevents loss of fluids by collecting it in the lymphatic vessels and returning it to the circulatory system

Digestion= help in the absorption of fats from food, prevents obesity

Excretion= assists in excretion of waste materials from the body

Transportation of nutrients= delivers nutrients in the body through the blood

Major Organs

Skin= forms germ-proof barrierNose= hairs and mucus trap germs and dirt

from airEars= wax inside traps germsEyelids= keeps germs out of your eyesTears= wash eyes cleanStomach= hydrochbris acid kills germs in

foodTonsils and Adenoids= kills germs in throatWhite Blood Cells= destroying germs

inside your bodySpleen= contains white blood cells which

fight infection

Lymph CapillariesLactealsLymph NodesLymph Vessels Main Lymphatic Ducts

Lymph NodeLymph nodes are small organs found in

clusters around the system in your neck, armpits and groin.

Make lymphocytes which destroy germs with chemicals called antibodies.

Special antibodies attacks specific antigens Are located along lymphatic pathwaysFilters any possible harmful partials from

the lymph before it travels to the blood stream

Center for lymphocyte production

The SpleenProduces lymphocytes (type of white blood

cells)Red pulp is concerned with filtration

activities, removing damaged red blood cells from the body

Reservoir of bloodPreserves iron and important components

from damaged blood cellsStored as bilirubin and ferritinStores monocytes (helps engulf and digest

bacteria and other harmful microorganisms

The Thymus-Most active in youth

-Enlarges as you grow older (then recedes at its peak)

-Produces hormones that regulate T-cell growth

Immunoglobins (Antibodies) Antibodies attack antigens, help activate proteins to attack or make changes in local

areas to protect it from antigens spreading

Immunoglobulin A: found in exocrine gland secretions. Breast milk, tears, nasal fluid, gastric juice, intestinal juice, bile and urine

Immunoglobulin G: plasma tissue fluids, is particularly effective against bacteria, viruses, and toxins. Actives group of immune system enzymes called complement

Immunoglobulin M: type of antibody that develops in the blood plasma in response to contact with certain antigens in food or bacteria. Also activates complement.

Immunoglobulin D: found on the surfaces of most B cells, especially those of infants. Also is important in activating B cells.

Immunoglobulin E: appears in exocrine secretions along with Lg A. It is associated with allergic reactions.

Primary/Secondary Immune Responses

Primary Immune Response= when B or T cells become activated for the first time after which some cells remain as memory cells

Secondary Immune Response= when the same antigen is encountered again

Active/Passive ImmunityNatural active immunity occurs when is a person is

exposed to a live pathogen, develops the disease and becomes immune

Artificially acquired active immunity can be gained by a vaccine (a substance that contains the antigen)

a vaccine stimulates a primary response against the antigen without causing symptoms of the disease

Natural passive immunity occurs during pregnancy, when certain antibodies are passed from the mother to the child through the bloodstream

Artificially acquired passive immunity is gained through injection of antibodies

Allergic Reactions

Allergic reactions to allergens are excessive immune responses that can lead to tissue damage

Mast cells release histamine and leukotrienes, producing a variety of effects

Delayed-reaction allergy= results from repeated exposure to substances that cause inflammatory reactions in the skin

Immediate-reaction allergy= inherited ability to overproduced IgE

Tissue Rejection Reactions

A transplant recipient’s immune system may react with foreign antigens on the surface of the transplanted tissue, causing a tissue rejection reaction

Closely matched tissues reduce the chance of tissue rejection, and use of immunosuppressive drugs may reduce rejection, although the individual may be more susceptible to infection

Autoimmunity

In autoimmunity disorders, the immune system manufactures antibodies against some of its own antigens

Autoimmune disorders may result from viral infection, faulty T cell development, or reaction to a nonself antigen that bears close resemblance to a self antigen

Diseases: HIVs

- “Human Immunodeficiency Virus”- Breaks down immune system by infecting immune cells- HIV infects vital cells in the human immune system such as helper T cells (specifically CD4+ T cells), macrophages, and dendritic cells-When CD4+ T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections.

Diseases: SCID(Severe Combined Immune Deficiency) A genetic disorder identified by the absence of

working T-lymphocytesCreates a defective antibody responseIt is the most severe form of primary

immunodeficienciesIts known as the bubble boy disease because the

patients are extremely vulnerable to infectious diseases

Patients are usually affected by severe bacterial, viral, or fungal infections early on and often present with, chronic diarrhea, interstitial lung disease, and failure to thrive

Scleroderm

Is a chronic systemic autoimmune disease

derma = skinLimited systemic

sclerosis/scleroderma

Diffuse systemic sclerosis/scleroderma

The cause is unknown

 affects the small blood vessels in all organs