3.2 Transport In Animals (blood) Flashcards
What is the composition of blood?
- Red blood cells- Transport O2
- White blood cells- Immunity
- Platelets- Clotting
- Plasma- transport of Glucose,amino acids,mineral ions and hormones (mostly consists of water)
What is the role of the blood?
To transport:
- gasses
- digested food
- nitrogenous waste (urea)
- platelets to site of injury
- antibodies
What is tissue fluid?
Fluid similar in composition to blood which transports substances from blood to cells and vice versa
How does tissue fluid differ to blood?
Has no cells/large plasma proteins
What is hydrostatic pressure?
Pressure exerted by a liquid on the walls of its container
What is oncotic pressure?
Tendency of water to move into the blood (via osmosis) as a result of plasma proteins
Which end of a capillary has a higher hydrostatic pressure?
The arteriole end
What end of the capillary has the highest oncotic pressure?
The venule end
How do substances exit the capillary?
The capillary endothelial wall has fenestrations in it
At what end of the capillary does fluid exit the capillary?
The arteriole end
What happens at the venule end of the capillary?
Water potential in blood is more negative due to less water so the oncotic pressure becomes higher in relation to hydrostatic pressure and some fluid reenters.
What is Lymph?
Fluid with the same composition of plasma/tissue fluid travelling in lymph vessels
What are the features of Lymph?
Less oxygen and nutrients than blood or tissue fluid
More waste products
Contains fatty acids
What are lymph nodes?
Lymphocytes that have collected together
Produce antibodies/intercept pathogens
How does tissue fluid enter lymph vessels?
Through the open ended ends
What adaptations do erythrocytes have?
- bi-concave shape provides a larger surface area
- no nucleus means more room for haemoglobin
What is the composition of haemoglobin?
4 polypeptides with 4 Fe + ions which O2 bind to
How is oxygen obtained at the lungs?
There is a high PP of O2 (high concentration)
Haemoglobin has a high affinity for oxygen
Haemoglobin is saturated by oxygen as lots of Haemoglobin bind to Fe ions
How is oxygen delivered to body tissues?
- Low pp of O2
- Haemoglobin has a low affinity for oxygen
- Oxygen dissociates from Haemoglobin causing oxygen to be released
- Haemoglobin has a low saturation of oxygen
What is the name of the curve formed by oxygen dissociation?
Sigmoid curve
What causes the sigmoid curve?
- Conformational change so ppO2 bring higher increases the affinity for oxygen
- This is called co-operative binding and unloading
- the second and third O2 molecule are easier to bind/unload
How does ppO2 effect O2 saturation?
Small increase of ppO2 = Large increase of O2 saturation
Small decrease of ppO2 = Large decrease of O2 saturation
How is foetal haemoglobin different?
Has a higher affinity for oxygen- Two polypeptide chains are different
Means that no matter ppO2 oxygen will be transferred
What happens to the sigmoid curve of a foetus?
Curve shifted to the left
What are the three ways CO2 are transported?
- 5% directly into plasma
- 10% bound to haemoglobin
- 85% in the form of hydrogen carbonate atoms
What is the function of carbonic anhydrase in the transport of CO2?
An enzyme which reacts the CO2 with water to form carbonic acid
What happens to the carbonic acid in transport of CO2?
It dissociates to form H+ and HCO3-
What do the H + ions in transport of CO2 combine with?
Haemoglobin to form haemoglobonic acid
How is Hydrogen carbonate removed from the blood cells?
Chloride ions are exchanged and while chloride ions go in the hydrogen carbonate comes out
What is the Bohr effect?
H + ions compete for space on haemoglobin molecules
H + ions displace the oxygen from haemoglobin
More oxygen is released to respiring tissues
What happens to the dissociation curve in reference to the Bohr effect?
Shifted down to the right
