3.3.4 Mass transport Flashcards
Explain how following risk factors influence onset of CHD
High blood cholesterol
High blood pressure
Smoking
HBC- Fatty deposition in artery walls
Arteroma formed
Increase bp
Lumen of arteries narrowed
HBP-
Damage to artery lining
Risk of aneurysm
Increased risk of blood clot blocking coronary arteries
Smoking-
Increase bp
Risk of aneurysm
Increases risk blood clot blocking coronary arteres
Reduced blood supply to heart
Increased risk of heart attack
Suggest + explain 3 ways risk factors cause cardiovascular disease
Smoking-
Co reduces O2 transport/ nicotine increases blood pressure
Saturated fat-
Raises blood cholesterol level
Alcohol/ salt-
Increases blood pressure
Suggest how high bp can result in less O2 reaching heart muscle
damage to artery walls
ref. to blood clot
blood clot can block arteries
ref. to coronary arteries;
lack of (oxygenated) blood flow to heart muscle
Suggest + explain why a low cholesterol diet might not result in a lower blood cholesterol level
cholesterol synthesized by the body
further detail e.g. made in liver / cholesterol made from
saturated fats;
genetic factors;
further detail e.g. hypercholesterolaemia / number of LDL receptors
Haemoglobin structure
Protein with quaternary structure
The Bohr effect
Cells produce CO2 when respiring
Increases rate if oxygen unloading
Dissociation curve shifts right but stays same shape
Saturation of blood with oxygen is lower for given pO2 meaning more oxygen is released
Animals adaption (haemoglobin)
Many animals adapted for their environment by possessing different types of haemoglobin with different oxygen transport properties
General pattern of blood circulation in mammal
Low SA:V ratio
Heart pumps blood through blood vessels to reach different parts of body
Body transports respiratory gases, products of digestion, metabolic waste, hormones
2 circuits
Heart to lungs and back to heart
Round the rest of the body
Heart has on blood supply- coronary arteries
Blood vessels entering and leaving heart, lungs and kidney
Coronary arteries- heart’s blood supply
Pulmonary vein - lungs to heart
Vena cava - body to heart
Pulmonary artery - heart to lungs
Aorta - heart to body
Renal vein - kidneys - heart
Renal artery - heart - kidney
Artery adaptions
Elastic tissue in wall
Thick muscle layer
Lumen - space at centre
Folded endothelium
Arteriolar adaptions
Arteries divide into arterioles
Thick walls
Narrow lumen
Elastic fibres
Vein adaptions
Thin muscle wall
Valves
Endothelium
Large lumen
Capillary adaptions
One cell thick endothelium
Leak due to tissue spaces
Lots of them
Tissue fluid
Small molecules that leave blood plasma like oxygen, water, nutrients
No big proteins as too large to be pushed through capillary walls
The rise and fall in blood pressure in the aorta is greater than in the small arteries. Suggest why.
Aorta is directly linked to to the heart so pressure is very high
Aorta has elastic tissue
Aorta has stretch/recoil
Humans and grasshoppers have very similar percentages of each base in their DNA but they are very different organisms
How is this possible?
Have different genes
So bases are in a different sequence
So different amino acids and therefore proteins
The DNA of the virus is different from that of other organisms.
Use your knowledge of DNA to suggest what this difference is.
Virus DNA
A not equal T, C not equal G
So no base pairing;
So DNA is not double stranded/is single stranded;
Give three ways in which courtship behaviour increases the probability of successful mating
Recognise species
Simulate release of gametes
Indication of sexual maturity
Tissue fluid formation and return
Start capillary bed- hydrostatic pressure greater in capillary than tissue fluid
The difference in hydrostatic pressure forces fluid out of capillaries into spaces around cells forming tissue fluid
At end of capillary bed, hydrostatic pressure low so water potential now lower than in tissue fluid so some is returned to capillaries by osmosis
Excess is drained by lymphatic system- from tissues back to circulatory system
Heart beat process
Blood enters atrium
Atrium wall contracts
Increases pressure in atrium
Causes atrioventricular valves to open
Blood passes into ventricle
Ventricle contracts increasing pressure
Atrioventricular valve closes when pressure greater than atrium
When ventricle has higher pressure than aorta semilunar valve open
After contraction higher pressure in aorta than ventricle cause semilunar valve to close
Formation of oxyhaemoglobin
Haemoglobin – a protein with a quaternary structure. Binds with oxygen to form oxyhaemoglobin
At lungs oxygen binds to haemoglobin
Difficult for first oxygen to bind.
Binding causes a change in the tertiary/quaternary structure of protein Exposes another oxygen binding site
Further oxygen molecules bind to haemoglobin more easily.
Bohr affect
Increased rate of respiration
Increase of carbon dioxide in blood.
Increase carbonic acid/decrease in pH.
Changes quaternary/tertiary structure of haemoglobin Oxygen dissociates more rapidly
Delivers more oxygen to respiring tissues.
Suggest why a lack of protein in the diet causes swelling (tissue fluid)
Less protein in blood
Water potential in blood too high
Water not drawn into capillary by osmosis
Fluid stays in tissues
Why is the water potential of the blood plasma is more negative at the venule end of the capillary than the arteriole end of the capillary ?
Water leaves capillary
Proteins in blood too large to leave capillary
Increases concentration of blood proteins so water potential
High absorption of salt from the diet can result in a higher than normal concentration of salt in the blood plasma entering capillaries. This can lead to a build-up of tissue fluid.
Explain how
Lower water potential of tissue fluid
Less water returns to capillary by osmosis
Explain 3 ways in which an insect’s tracheal system is adapted for efficient gas exchange
Tracheoles have thin walls so short diffusion distance to cells
High branched tracheoles so large surface area
Abdominal pumping moves air to maintain diffusion gradient
