Lymphatic System and Immunity

By Melanie E.
Alexis C.
Lavinia G.
General Functions
 Lymphatic 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 barrier
 Nose= hairs and mucus trap germs and dirt from air
 Ears= wax inside traps germs
 Eyelids= keeps germs out of your eyes
 Tears= wash eyes clean
 Stomach= hydrochbris acid kills germs in food
 Tonsils and Adenoids= kills germs in throat
 White Blood Cells= destroying germs inside your
 Spleen= contains white blood cells which fight
Lymph Capillaries
Lymph Nodes
Lymph Vessels
Main Lymphatic Ducts
Lymph Node
 Lymph nodes are small organs found in clusters
around the system in your neck, armpits and
 Make lymphocytes which destroy germs with
chemicals called antibodies.
 Special antibodies attacks specific antigens
 Are located along lymphatic pathways
 Filters any possible harmful partials from the
lymph before it travels to the blood stream
 Center for lymphocyte production
The Spleen
 Produces lymphocytes (type of white blood
 Red pulp is concerned with filtration activities,
removing damaged red blood cells from the
 Reservoir of blood
 Preserves iron and important components
from damaged blood cells
 Stored as bilirubin and ferritin
 Stores 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
-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
 Immunoglobulin M: type of antibody that develops in the blood plasma in
response to contact with certain antigens in food or bacteria. Also activates
 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
 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 Immunity
 Natural 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
 In autoimmunity disorders, the immune system
manufactures antibodies against some of its own
 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-lymphocytes
Creates a defective antibody response
It is the most severe form of primary
Its 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
 Is a chronic systemic
autoimmune disease
derma = skin
Limited systemic
Diffuse systemic
The cause is unknown
affects the small blood
vessels in all organs