a clot consists of platelets trapped in a web of ______.
fibrin - end product
white cells, red cells trapped in clot
the enzyme that breaks down the clot is ______.
plasmin - breaks down fibrin strands
what is the difference between the intrinsic and extrinsic clotting pathways?
intrinsic:
triggered by factors released by platelets
takes 5 mins
extrinsic:
trigger by exposure to proteins exposed by cut in vessel
takes 15 seconds
what is responsible for blood types?
cells markers on the outside of red blood cells
why are they (blood types) called antigens?
because they can stimulate antibody protection
the main blood antigens are ______.
ABO - chief marker
what antibodies do Rh positive and RH negative people have?
none
when are Rh antibodies formed?
when Rh people are exposed to Rh+ blood
what happens when A blood is given to a B person?
B's A antibodies attache to the A cells and are destroyed- a transfusion reaction
what is a hematrocrit?
the percentage of red blood cells in a simple of whole blood
Normal blood counts:
Red blood cells - 5 million
White blood cells- 5000-10000
platelet: 250,000/cubic milometer
how is lymph different from blood?
it goes in only one directions (doesn't circulate)
there is no pump (heart) in the system
has no red blood cells
no platelets or clotting factors
does not deliver things (oxygen/nutrients)
transport is interrupted by filters called lymph nodes
where is lymph returned to the main circulation?
subclavian veins
in addition to its major role in immunity, what other two things does the lymphatic system do?
transports fats from the intestine to the bloodstream
picks up extra tissue fluid
what are muscosa associated lymphatic tissues?
mobile lymphotcytes that move about beneath the mucosal lining of gut and airs to protect against invasion of the body through mucus membranes - not fixed
what are peyer's patches?
a fixed concentration of lymphoctes at the junction of the small and large intestine
what are tonsils?
small organs full of lymphocytes that protect the throat and upper airway