lymphatic system
� consists of a network of lymphatic vessels, lymph nodes, the spleen, the thymus gland, and the tonsils
� organs collect excess tissue fluid thought the body and return it to the circulatory system
� works with the immune system to form the groups of cel
lymph
fluid inside a lymphatic vessel
lacteals
lymph vessels around the small intestines that are able to pick up absorbed fats for transport
lymphatic vessels
� form an extensive network of vessels throughout the entire body, however they are not in a closed loop like the circulatory system
� serve as one-way pipes conducting lymph from the tissues toward the thoracic cavity
� since it's a low pressure system,
lymphatic capillaries
very small capillaries in the tissues where excessive tissue fluid enters to begin the trip back to the circulatory system via lymphatic vessels
right lymphatic duct
smaller of the two lymphatic ducts, drains the right arm and the right side of the neck and chest and empties lymph into the right subclavian vein
thoracic duct
larger of the two lymphatic ducts, drains lymph from the rest of the body and empties into the left subclavian vein
lymph nodes
� lymph glands
� small organs composed of lymphatic tissue located along the route of the lymphatic vessels
� house lymphocytes and antibodies and therefore work to remove pathogens and cell debris as lymph passes though them on its way back to the thorac
lymph glands
lymph nodes
sites for lymph nodes
� axillary: located near the armpits, drain arms and shoulder region; breast cancer cells may be detected at this site
� cervical: located near the neck, drain head and neck; may be enlarged during upper respiratory infections
� inguinal: located near the
tonsils
� a collection of lymphatic tissue located on each side of the throat or pharynx
� there three sets of tonsils: palatine tonsils, pharyngeal tonsils (adenoids), lingual tonsils
� all tonsils contain a large number of leukocytes and act as filters to prote
pharynx
throat
adenoids
pharyngeal tonsils
spleen
� located in the upper left quadrant of the abdomen, consists of lymphatic tissue that is highly infiltrated with blood vessels that spread out into the blood sinuses
� it filters out and destroys old red blood cells, recycles the iron, and also store som
blood sinuses
spread-out blood vessels within the spleen that result in slow-moving blood flow.
macrophage
large phagocytic cells in the body that that identify and remove pathogens and worn-out red blood cells; ingesting and digesting any pathogen they encounter
thymus gland
� located in the upper portion of the mediastinum and is essential for the proper development of the immune system
� it assists the body with immune function and the development of antibodies
� produces thymosin which changes lymphocytes to T cells
thymosin
hormone produced by the thymus gland; changes lymphocytes to T lymphocytes (T cells)
T lymphocytes
� T cells
� produced when thymosin changes lymphocytes and plays an important role in the immune response
T cells
T lymphocytes
natural immunity
� innate immunity
� is not specific to a particular disease and does not require prior exposure to the pathogenic agent, e.g. macrophages ability to attack pathogens
passive acquired immunity
results when a person receives protective substances produced by another human or animal, e.g. maternal antibodies crossing the placenta or an antitoxin or gamma globulin injection
active acquired immunity
� develops following direct exposure to a pathogenic agent which stimulates the body's immune response; once the body has successfully defeated a virus, it will be able to more quickly recognize and kill it in the future
� immunizations (vaccinations) are
immune response
� a series of different mechanisms all geared to neutralize a pathogen
� consists of two distinct and different processes: humoral immunity (antibody-mediated immunity) and cellular immunity (cell-mediated immunity)
antigens
foreign proteins that stimulate the immune response
humoral immunity
� antibody-mediated immunity
� the production of B lymphocytes (B cells) which respond to antigens by producing antibodies
antibody
a protective protein produced in response to an antigen
antigen-antibody complex
complex either targets the foreign substance for phagocytosis or prevents the infectious agent from damaging healthy cells
cellular immunity
� cell-mediated immunity
� involves the production of T cells and natural killer (NK) cells which physically attack and destroy pathogenic cells
natural killer cells
� NK
� cytotoxic cell which physically attack and destroy pathogenic cells
cytotoxic
� cells which physically attack and destroy pathogenic cells
� Example: T cells, natural killer cells
nosocomial infection
an infection acquired as a result of hospital exposure
cross infection
a nosocomial infection which occurs when a person acquires a pathogen from another patient or healthcare worker
reinfection
a nosocomial infection which takes place when a patient becomes infected again with the same pathogen that originally brought them to the hospital
self-infection
a nosocomial infection which occurs when a person becomes infected in a different part of the body by a pathogen from another part of their own body
allergen
an antigen that causes an allergic reaction
autoimmune disease
� a disease resulting from the body's immune system attacking its own cells as if they were pathogens
� Example: systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis
hives
appearance of wheals as part of an allergic reaction
immunocompromised
� immunodeficiency disorder
� having an immune system that is unable to respond properly to pathogens
immunodeficiency disorder
immunocompromised
immunoglobulins
antibodies secreted by the B cells; all antibodies are immunoglobulins and assist in protecting the body and its surfaces from the invasion of bacteria
inflammation
the tissues' response to injury from pathogens or physical agents; characterized by redness, pain, swelling, and feeling hot to touch
lymphedema
edema appearing in the extremities due to an obstruction of the lymph flow thought the lymphatic vessels
opportunistic infections
infectious diseases associated with patients who have compromised immune systems and therefore a lowered resistance to infections and parasites
urticaria
severe itching associated with hives
anaphylactic shock
� anaphylaxis
� life-threatening condition resulting from a severe allergic reaction
anaphylaxis
anaphylatic shock
elephantiasis
inflammation, obstruction, and destruction of the lymph vessels resulting in enlarged tissues due to edema
Hodgkin's disease
� HD
� Hodgkin's lymphoma
� cancer of the lymphatic cells found in concentration in the lymph nodes
lymphadenitis
� swollen glands
� inflammation of the lymph nodes
swollen glands
lymphadenitis
mononucleosis
acute infectious disease with a large number of abnormal lymphocytes
non-Hodgkin's lymphoma
� NHL
� cancer of the lymphatic tissues other than Hodgkin's lymphoma
AIDS-related complex
� ARC
� early stage of AIDS where there is a positive test for the virus, but only mild symptoms of weight loss, fatigue, skin rash, anorexia
graft vs. host disease
� GVHD
� serious complication of bone marrow transplant (graft) where immune cells from the donor bone marrow attack the recipient's tissues
Kaposi's sarcoma
� KS
� form of skin cancer frequently seen in patients with AIDS; consists of brownish-purple papules that spread from the skin and metastasize to internal organs
Pneumocystis carinii pneumonia
� PCP
� pneumonia common in patients with AIDS that is caused by infection with an opportunistic parasite
sarcoidosis
disease of unknown cause that forms fibrous lesions commonly appearing in the lymph nodes, liver, skin, lungs, spleen, eyes, and small bones of the hands and feet
severe combined immunodeficiency syndrome
� SCIDS
� disease seen in children born with a nonfunctioning immune system; often children forced to live in sealed sterile rooms
lymphangiography
X-ray taken of the lymph vessels after the injection of dye into the foot; the lymph flow through the chest is traced
lymphadenectomy
removal of a lymph node