Peak Performance

Question 1

What’s aerobic capacity?

Answer 1

Ability to take in, transport and use oxygen

Question 2

Describe heart rate

Answer 2

Everyone has a slightly different resting heart rate caused by many factors
Large heart- lower due to expelling more blood per beat

Question 3

Define myogenic

Answer 3

Ability to contract without external nervous stimulation

Question 4

What is stroke volume?

Answer 4

Volume of blood pumped out of the left ventricle each time it contracts

Question 5

What is the equation for cardiac output?

Answer 5

Stroke volume x heart rate

Question 6

Describe how the heart beats

Answer 6

Depolarisation at the SAN generating an impulse spreading across right to left atria causing contraction
Impulses pass to ventricles via AVN following a delay
Impulses go to Purkyne fibres (conduct impulses to apex of ventricles)
Impulses spread up through ventricle walls causing contraction from apex upwards
blood squeezed into arteries

Question 7

What is the SAN?

Answer 7

Sinoatrial node - small area of specialised muscle fibres locating in wall of right atrium below superior vena cava (Pacemaker)

Question 8

Why is there a delay in heart beats?

Answer 8

Ensures atria have finished contracting and that the ventricles have filled with blood before contraction

Question 9

What does the non-conducting layer do?

Answer 9

Prevent waves of electrical activity from being passed directly to the ventricles

Question 10

What is an ECG?

Answer 10

Measures electrical activity of the heartbeat

Change in polarisation causes a small electrical current to be detected

Question 11

Whats the P wave?

Answer 11

Depolarisation of the atria

Question 12

Whats the PR interval

Answer 12

Time taken for impulses to be conducted from SAN arcoss to ventricles through AVN

Question 13

Whats the QRS complex?

Answer 13

Wave of depolarisation

Question 14

Whats the T wave

Answer 14

Repolarisation of ventricles

Question 15

How is an ECG carried out?

Answer 15

Electrodes attached to chest

Question 16

What is tidal volume?

Answer 16

volume of air inhaled and exhaled in one breath

Question 17

What is basal metabolic rate?

Answer 17

rate of respiration

Question 18

What is minute volume?

Answer 18

Volume of air inhaled in one minute

Question 19

What is vital capacity?

Answer 19

Max amount of air a person can inhale and exhale

Question 20

Describe slow twitch fibres?

Answer 20

Specialised for slower contraction and long periods of excerise
Red (lots of myoglobin)
Many mitochondria
Little sarcoplasmic reticulum
Low glycogen content
Capillaries
Fatigue-resistant

Question 21

Describe fast twitch fibres?

Answer 21

Specialised for faster contraction
White (little of myoglobin)
Little mitochondria
Many sarcoplasmic reticulum
High glycogen content
Few Capillaries
Fatigue quickly

Question 22

Which nerves are involved in controlling heart rate?

Answer 22

Sympathetic nerve (Increasese)and parasympathetic nerve (vagus nerve)(decreases)

Question 23

What are the axis of ECG?

Answer 23

X = time
Y = electrical activity

Question 24

How is heart rate increased?

Answer 24

Skeletal muscles contract and stretch receptors in muscles are stimulated sending impulses to the CCC increasing heart rate

Question 25

How does increase heart rate increase cardiac output?

Answer 25

Increases venous return increasing stroke volume

Question 26

How is cardiac output prevented from rising too far?

Answer 26

Pressure receptors in aorta and carotid atery send impulses back to CCC and send inhibitory impulses to SA node

Question 27

Describe hormonal control of heart rate

Answer 27

Adrenaline directly influences SA node increasing heart rate