animal transport

Question 1

blood pathway in heart

Answer 1

RIGHT

• in vena cava
• right atrium
• right ventricle
• out pulmonary artery

LEFT

• in pulmonary vein
• left atrium
• left ventricle
• out aorta

Question 2

LORD

Answer 2

Left Oxygenated Right Deoxygenated

Question 3

coronary arteries + cardiac muscle

Answer 3

• thin, lie over the heart
• supply cardiac muscle with oxygen
• lack of oxygen = angina

cardiac muscle cells contain lots of mitochondria for energy and intercalated discs for synchronised contractions

cardiac muscle is myogenic - initiates own contraction

Question 4

chambers

Answer 4

atria - thinnest, low pressure

ventricles
RIGHT - thin, medium/low pressure
LEFT - thick, high pressure

Question 5

cardiac cycle

Answer 5

ATRIAL SYSTOLE

• blood enters atria, pressure increases
• pressure in atria bigger than the pressure in the ventricle
• atrioventricular valves open
• blood flows into ventricles as the atria contract

VENTRICULAR SYSTOLE

• blood enters ventricles, pressure increases
• pressure in ventricles bigger than in atria
• atrioventricular close
• pressure in ventricles bigger than in arteries
• semilunar valves open
• ventricles contract, blood forced into arteries

Question 6

cardiac output

Answer 6

= heart rate x stroke volume

Question 7

heart rate

Answer 7

60/ time taken for 1 cardiac cycle

Question 8

SAN

Answer 8

sinoatrial node
TOP of right atria

generates electrical impulses
starts a wave of excitation in right atrium which spreads to left causing atrial systole

Question 9

AVN

Answer 9

atrioventricular node
TOP of the interventricular septum

conducts wave of excitation through ventricles
delays the wave allowing time for atria to finish contracting and ventricles to fill with blood
directs excitation to Purkyne tissues which spread through walls of both ventricles

Question 10

oxygen transport

Answer 10

association of oxygen = high partial pressures

dissociation of oxygen = low partial pressures

Question 11

foetal haemoglobin

Answer 11

higher affinity for oxygen as it must be able to associate with oxygen in places where adult haemoglobin has dissociated such as in placenta and surrounding fluid

Question 12

affinity

Answer 12

the ability of haemoglobin to pick up oxygen

Question 13

HCO3- red blood cells

Answer 13

1. CO2 diffuses into red blood cells
2. in red blood cells, CO2 reacts with water, in a reaction catalysed by carbonic anhydrase, forming carbonic acid
3. carbonic acid releases H+ ions and HCO3- ions
4. HCO3- ions diffuse ex cell into plasma

Question 14

Bohr effect

Answer 14

1. increased CO2 concentration causes an increase in the production of H+ ions
2. increases acidity
3. alters haemoglobin shape
4. decreases haemoglobin’s affinity for oxygen
5. less association more dissociation