Haemoglobin & Circulatory System Flashcards
Haemoglobin is a quaternary protein with high affinity. What does high affinity mean?
Will readily combine with oxygen
What is partial pressure a measure of?
Oxygen concentration
What does haemoglobin’s affinity for oxygen depend on?
Partial pressure of oxygen
Oxygen loads in high pp, unloads in low pp
What does 100% saturation on the oxygen dissociation curve mean?
Every haemoglobin is carrying 4 oxygen molecules
High partial pressure of oxygen means high affinity
What does 0% saturation on the oxygen dissociation curve mean?
No haemoglobin carrying oxygen
Low partial pressure, low saturation
Why is the oxygen dissociation curve S shaped?
First oxygen binds to haemoglobin and causes change in shape
Allows next 2 oxygen to join easier
As haemoglobin is more saturated, it’s harder for oxygen molecules to join
An increase of CO2 shifts the oxygen dissociation curve which way?
Right
An increase in pH shifts the oxygen dissociation curve which way?
Left
What is the Bohr effect?
More oxygen is released in tissues with higher partial pressure of CO2
Explain the Bohr effect on the oxygen dissociation curve
Haemoglobin gives up oxygen at high partial pressures of CO2
Cells respire and produce CO2
Increases rate of oxygen unloading
Curve shifts right
An organism who lives in low oxygen concentrations- will it have a higher or lower affinity?
Higher
If an organism is very active and oxygen is in high demand, will they have a high or low oxygen affinity?
Low
What is a mass transport system?
Moving substances over large distances
Why do multicellular organisms need mass transport systems and specialised exchange organs?
Small surface area to volume ratio
The circulatory system is made up of what?
Heart
Blood vessels
There are two circulatory systems. Where do they go?
Lungs
Rest of body
What arteries provide blood supply to the heart muscle?
Left and right coronary arteries
Renal associates with which organ?
Kidney
Hepatic associates with which organ?
Liver
Describe the structure of arteries and explain why they are needed
Elastic tissue to stretch and recoil
Folded endothelium to maintain pressure
Thick muscular walls to be under high pressure
All arteries carry oxygenated blood except which artery?
Pulmonary artery
Carries deoxygenated blood to lungs
Arteries split into arterioles. How do arterioles direct blood flow to areas in demand?
Arterioles contain muscles
Can contract to restrict blood flow
Describe the structure and function of veins
Take blood back to heart under low pressure
Wide lumen with little elastic tissue
Valves to prevent back flow of blood
How is blood flow through veins encouraged?
Muscle contraction
