BLOOD
Functions:
● Transport of digested food products from villi to other parts of the body
● Transport of food molecules from storage —> cells that need them
● Transport of excretory products to excretory organs
● Transport of chemical messages (hormones) from glands —> rest of body
● Homeostasis- vasoconstriction and vasodilation
● Transport oxygen for aerobic respiration and CO2 to be expelled from lungs
● Defense- blood clotting*, provide immunity through lymphocytes
● Act as buffer of pH changes
*How does blood clot?
a. Palettes adhere to damaged site of blood vessel, release chemicals to attract more (PF)
b. platelet plug seals injury to stop bleeding
c. cascade of clotting factors, fibrinogen converted to fibrin
d. fibrin form mesh like structure to trap platelets
Erythrocytes
● contain red pigment haemoglobin (protein) responsible for oxygen transport
● biconcave shape —> large SA:V for diffusion of gases
● No nucleus —>. Max space available to pack Hb
● Flexible to fit through capillaries
HAEMOGLOBIN AND OXYGEN
Oxygen dissociation curve is plotted as pKa of oxygen (x) against % saturation of haemoglobin
(y). It has a sigmoidal shape because:
● First oxygen is slowest to bind to first haem groups but once bound haemoglobin
molecules undergoes conformational change making it easier for next oxygen molecule
to be taken on
● 4th oxygen molecule binds more slowly than second and third because the
haemoglobin molecule is become more saturated
● 100% saturation is not reached due to oxygen tension of lungs
Functions:
● Transport of digested food products from villi to other parts of the body
● Transport of food molecules from storage —> cells that need them
● Transport of excretory products to excretory organs
● Transport of chemical messages (hormones) from glands —> rest of body
● Homeostasis- vasoconstriction and vasodilation
● Transport oxygen for aerobic respiration and CO2 to be expelled from lungs
● Defense- blood clotting*, provide immunity through lymphocytes
● Act as buffer of pH changes
*How does blood clot?
a. Palettes adhere to damaged site of blood vessel, release chemicals to attract more (PF)
b. platelet plug seals injury to stop bleeding
c. cascade of clotting factors, fibrinogen converted to fibrin
d. fibrin form mesh like structure to trap platelets
Erythrocytes
● contain red pigment haemoglobin (protein) responsible for oxygen transport
● biconcave shape —> large SA:V for diffusion of gases
● No nucleus —>. Max space available to pack Hb
● Flexible to fit through capillaries
HAEMOGLOBIN AND OXYGEN
Oxygen dissociation curve is plotted as pKa of oxygen (x) against % saturation of haemoglobin
(y). It has a sigmoidal shape because:
● First oxygen is slowest to bind to first haem groups but once bound haemoglobin
molecules undergoes conformational change making it easier for next oxygen molecule
to be taken on
● 4th oxygen molecule binds more slowly than second and third because the
haemoglobin molecule is become more saturated
● 100% saturation is not reached due to oxygen tension of lungs
