5. Lymphatic System and Immunity Chp 16 (exam 2) Flashcards
Functions of lymphatic system
- return excess tissue fluid back to the bloodstream
- lacteals absorb fat from villi of small intestine
- Help defend body against disease
lymphatic capillaries
closed-end tubes that collect interstitial fluid.
The cells forming the capillaries overlap, creating flap-like valves which open with increases interstitial pressure
lymphatic vessels
vein-like vessels with valves: return lymph back to the venous system by means of trunks
lymph nodes
round to ovoid structures located along the lymphatic vessels; with macrophages and lymphocytes
function of lymph nodes
filter infectious organisma and other debris
produce lymphocytes
surveillance
structure types of lymph nodes
capsule
nodules
lymph sinuses
Capsule
fibrous connective tissue
nodules
masses of lymphocytes & macrophages
lymph sinuses
chambers and channels through which lymph travels
Additional lymph organs
Spleen
Thymus
Spleen
function
largest lymph organ(upper left abd.)
purifies blood
immune function
stores blood (1cup)
Thymus
function
produces T lymphocytes and thymosin (stimulates T cell maturation). Progressive shrinking post puberty
disease
an abnormal state of the body in which the body is not capable of carrying on required functions
pathogens
disease causing organism
ex. bacteria, viruses, parasites, microorganisms, etc
Etiology
the study of any disease; origin, cause, classification.
innate defense
nonspecific (innate)
body’s general defense against everything
(shotgun)
first line of defense
Mechanical
skin & mucous membranes
2nd line of defense
- chemical barriers (Hcl, tears, interferons, defensins,collectins)
- fever
- natural killer
- inflammation
- phagocytosis
Adaptive defense
specific - that is they target specific things
3rd LOD
Specific Defense(Sniper) Immunity
interferons
lymphocytically produces: bind to uninfected cells stimulating them to produce virus replicating inhibiting proteins & stimulating phagocytosis
T cells
attach directly to the foreign invader. they are activated when a macrophage phagocytizes a bacterium, shifting some of the bacterium’s antigens to the macrophages surface as a part of major histocompatability complex.
Other T cells
Helper T Cytotoxic T Memory T Suppressor T Natural Killer T
Helper T
(cheerleader) regulates and stimulates other cells
Cytotoxic T
(assasin) recognizes non-self antigens of cancerous/virally infected cells and destroys them via perforin. Some give rise to memory T cells.
Memory T
(historian) if there is a second exposure, Memory T differentiates to Cytotoxic T
Suppressor T
(peace maker) inhibit B & T cell activity
B cells
humoral immune response (fluid)
activated by exposure to antigen that fits receptors or being activated by helper T
B cell clones differentiate into
memory B cells or plasma cells that secrete antibodies which causes compliment activation
action of antibodies
- attack antigens to cause agglutinatin then phagocytic elimination
- activate complement (a group of proteins in plasma which are activated by antibodies)
- stimulate inflammation via mast cells