cardiac conduction

Question 1

order that the impulse travels

Answer 1

SAN –> Atrial systole –> Bundle of HIs –> Bundle branches –> AVN –>vantricular systole

Question 2

what does myogenic mean

Answer 2

has the ability to generate its own electrical impulse

Question 3

what happens in the diastole phase

Answer 3

the atria fills with blood and pressure builds within these chambers, as the pressure increases, the valves begin to slowly open and let small amounts of blood through

Question 4

what happens in the systole phase

Answer 4

1. atrial systole phase- valves forced open, both atrial contract and remaining blood is forced into the ventricles
   ventricular systole phase
2. blood is now in the ventricles, ventricles now contract increasing the pressure within these chambers
3. aortic semilunar valve and pulmonary semilunar valve are forced open, allowing blood to be pushed through into the aorta or pulmonary artery

Question 5

order of the impulse travel:

Answer 5

impulse starts in the SAN, then travels down into the AV node and onto the Bundle of His, these impulses here stimulate the atria, from here the pulse travels down the left and right branches and down the purkinje fibres, here the ventricles are squeezed.

Question 6

stroke volume

Answer 6

volume of blood pumped by the left ventricle of the heart per beat, untrained average vol= 70ml

Question 7

heart rate

Answer 7

number of beats per minute. average male resting HR= 70bpm
average female resting HR= 72bpm

Question 8

cardiac output

Answer 8

volume of blood pumped by left ventricle of the heart in one minute. untrained person at rest= 5.6 litres per min

Question 9

equation for cardiac output

Answer 9

SV x HR

Question 10

short term effects during exercise

Answer 10

• increased HR due to rising adrenaline levels
• increased cardiac output
• increase in SV due to stronger ventricular contractions

Question 11

long term effects during exercise

Answer 11

• number of red blood cells increase which improves the body’s ability to transport oxygen to muscles
• heart muscle gets bigger (hypertrophy)
• resting heart rate decreases

Question 12

what happens to the heart during submaximal exercise

Answer 12

cardiac output does not increase after training

Question 13

what happens to the heart during maximal exercise

Answer 13

cardiac output increases