Language of Medicine - Chapter 14 Flashcards
Lymphatic and Immune System
define lymph
clear, watery fluid that surrounds the body cells + flows in a system in the thin-walled lymph vessles that extends throughout the body
which wbc are rich in lymph?
lymphocytes + monocytes
what does lymph contain?
water, salts, sugar, wastes of metabolism (urea + creatine)
define interstitial fluid
fluid that surrounds the body cells
what are the functions of the lymphatic system?
- drainage system to transport needed proteins + fluid that have leaked out of the blood capillaries back to bloodstream via veins
- lymphatic vessels in intestines absorb lipids from the small intestines + transport them to bloodstream
- defence of body against foreign organisms (bacteria + viruses)
define lymph capillaries
begin at spaces around cells throughout the body
- thin walled tubes
- carry lymph from tissue spaces to larger lymph vessels
fine lymph vessels
thicker walls than lymph capillaries
- contain valves so that lymph flows in one direction
define lymph nodes
collections of stationary lymph tissue
- located along the path of lymph vessels
- produce lymphocytes + filter lymph + tap substances from infectious, inflammatory + cancerous lesions
where are cervical lymph nodes located
neck
where are axillary lymph nodes located
armpit
where are mediastinum lymph nodes located
chest
where are mesenteric lymph nodes located
intestinal
where are paraaortic lymph nodes located
lumbar
where are inguinal lymph nodes located
groin
define tonsils
masses of lymph tissue in the throat near the back of the mouth
define adenoids
enlarged lymph tissue in the part of the throat near the nasal passages
where is the right lymphatic duct + thoracic duct located?
upper chest
define B lymphocytes (B cells)
fight disease
- present in the nodes
- produce antibodies
- originate in bone marrow
define T lymphocytes (T cells)
attack bacteria + foreign cells by accurately recognizing a cell as foreign + destroys it
- help B cells make antibodies
- originate in thymus gland
define the spleen
located in the LUQ
- next to stomach
functions:
- destruction of old erythrocytes by macrophages (hemoglobin converted to bilirubin in liver and excreted into bile)
- filtration of microorganisms + other foreign material from the blood
- activation of lymphocytes (B cells produce antibodies - T cells attack foreign material)
- storage of blood (especially erythrocytes + platelets)
define thymus gland
located in upper mediastinum between lungs
- during fetal / child life it is large - becomes smaller with age
function:
- ability to protect body from disease (especially in childhood)
define immune system
specialized system to defend the body against antigens (toxins, bacterial proteins, foreign blood cells)
includes:
- leukocytes, neutrophiles, monocytes, macrophages, lymphoid organs like lymph nodes, spleen, thymus gland, and adenoids, produce lymphocytes + antibodies
define immunity
body’s ability to resist foreign organisms + toxins that damage tissues + organs
define natural immunity
- resistance present at birth
- not dependent on previous exposure to an antigen
neutrophils travel to infected area + ingest bacteria while monocytes, macrophages + lymphocytes (NK cells) participate in body’s natural immunity against infection
