Immune system-blood Flashcards
3 main types of cell in blood
erythrocytes
leukocytes
platelets (thrombocytes)
haematocrit
% of blood volume that is erythrocytes
bulk flow
rapid flow of blood throughout the body
erythrocytes main facts
no nucleus or organelles
no division
produced in bone marrow
short life span, destroyed in spleen or liver
breakdown product of haemoglobin
bilirubin
makes plasma yellow
recipe for RBCs
amino acids
lipids
carbohydrates
iron
folic acid
vitamin B12
% of iron in body
50% haemoglobin
25% body cells
25% bound to ferritin in liverh
how is iron transported to bone marrow
transferrin-plasma iron transport protein
normal haemoglobin levels men and women
14g/100ml
15.5g/100ml
normal haematocrit for men and women
45%
42%
folic acid
found in leafy plants, yeast, liver
needed to make thymine
vitamin B12
needed by folic acid
found in animal products
absorbed in gastrointestinal tract via an intrinsic factor
anaemia causes
low RBC count
low haemoglobin per RBC
both
deficiency of iron, folic acid or vitamin B12
how are erythrocytes replaced
kidneys release a hormone: erythropoietin to stimulate erythropoiesis
erythropoiesis
eg, decrease O2 to kidneys
kidneys secrete erythropoietin, increase in plasma erythropoietin, bone marrow increases production of erythrocytes, increase in blood haemoglobin conc, increase in blood oxygen carrying capacity and restoration of oxygen delivery
haemostasis
stoppage of bleeding
why do blood vessels constrict when they are severed
slows blood flow to the area
presses endothelial surfaces together inducing a stickiness to glue them together
only possible in microcirculation
bleeding prevention
formation of platelet plug
blood coagulation
platelets role in plug and clotting
adhere to collagen via an intermediary known as von Willebrand factor
collagen is exposed when injury to a vessel disrupts the endothelium
platelet activation
platelets release ADP and serotonin to induce changes in metabolism, shape and surface protein expression on platelets
why do platelets release actin and myosin
to allow contraction
fibrinogen
plasma protein that builds up and supports the platelet plug
EDTA
prevents blood clotting by ‘mopping up’ calcium
Heparin
naturally found on endothelial cells and prevents clotting by activating a plasma protein called anti thrombin III
calcium remains in solution so cells can still function
serum vs plasma
serum tube can clot and once centrifuged, there will be no clotting factors
a tube with heparin for example after centrifugation would contain plasma and clotting factors
types of leukocytes
lymphocytes
monocytes
polymorphonuclear granulocytes
types of granulocytes
neutrophils
eosinophils
basophils
leukocytes normal human blood amount
7000 per mm3 of blood
antibodies in the blood of different blood types
A: anti B
B: anti A
AB: neither
O: both anti A and anti B
