Download Lymphatic System Terms Edema- an abnormal accumulation of fluid

Lymphatic System Terms
Edema- an abnormal accumulation of fluid in body parts and tissue; causes swelling
lymphatic vesselslymph- the watery fluid in the lymph vessels collected from tissue space; only flows towards
the heart.
lymphatic collecting vessels- Large lymphatic vessels that transfer lymph from lymphatic
capillaries to ducts
right lymphatic duct- Duct that drains lymph from the right arm, right side of the head, and
thorax.
thoracic duct- Duct that receives lymph form the rest of the body not being drained by the
thoracic duct.
lymph nodes- a mass of lymphatic tissue
lymphocytes- angular white blood cells formed in bone marrow that mature in lymphoid tissue;
trap foreign substances.
cortex- the outer surface area of an organ
follicles- collections of lymphocytes found in the cortex
germinal centers- dark staining centers of follicles that enlarge when lymphocytes/B-cells
generate daughter cells called plasma cells
plasma cells- daughter cells generated in germinal centers that release antibodies
medulla- the inner region of an organ or tissue
afferent lymphatic vessels- Convex side of a lymph node in which lymph enters
efferent lymphatic vessels- Convex side of a lymph node in which lymph leaves; forms hilus
hilus- Indented area in a lymph node formed by efferent lymphatic vessels in which lymph exits
spleen- Blood rich organ that filters blood located on the left side of the abdominal cavity and
extends around the anterior aspect of the stomach
thymus gland- Lymphatic mass that produces thymosin which program lymphocytes to do their
protective roles; located in the throat overlying the heart
tonsils- Small masses of lymphatic tissue that ring the pharynx that trap and remove foreign
pathogens from the throat
Peyer's patches- Small masses of lymphatic tissue found in the walls of the small
MALT (Mucous-associated lymphatic tissue)- Acts a sentinel to protect the upper respiratory
and digestive tracts from attacks of foreign matter entering cavities (Tonsils and Peyer’s
Patches)
nonspecific defense system- System that responds immediately to protect the body from
foreign substances, whatever they are
specific defense system (immune system)- System that mounts attack on particular foreign
substances
antigen- Any substance that when introduced to the body, is recognized as foreign and
activates the immune system
pathogen- disease causing microorganism (e.g. Virus, bacteria, fungi)
phagocytes- Cell capable of engulfing and digesting particles or cells harmful to the body
NK cells- Lymphocytes that can lyse and kill cancer cells and virus-infected body cells before
triggering the immune sytem
perforins- a protein, released by killer cells of the immune system, that destroys targeted cells
by creating lesions like pores in their membranes.
inflammatory response- Nonspecific response triggered when tissue is damaged
histamine- A substance that causes vasodilation and increased vascular permeability
kinins- Group of polypeptides that dilate arterioles, increase vascular permeability, and induce
pain
diapedesis- the passage of blood cells through intact vessel walls into the tissues.
pus- The fluid product of inflammation composed of white blood cells, debris of dead cells, and
thin fluid.
interferons- Small protein secreted by virus infected cells to defended non-infected cells
pyrogens- an agent or chemical substance that includes fever
humoral immunity- Provided by antibodies in the body’s humors or fluids
cell-mediated immunity- Immunity when lymphocytes defend the body
B cells- Cells that produce antibodies and oversee humoral immunity
T cells- Lymphocytes that mediate cellular immunity; include helper, killer, suppressor, and
memory cells.
macrophages- Cells important in the immune response as an antigen presenter to T and B cells;
abundant in lymphatic and connective tissue.