Investigate the effect of exercise on the pulse rate of a human. Flashcards
Name two sites on the human body where the pulse can be easily located.
Radial artery (wrist)
Carotid artery (neck)
In which type of blood vessel (artery or vein) can the pulse be detected? Give a reason for your answer.
Artery
The pulse is caused by the expansion and recoil of the artery walls due to pressure waves created by the contraction of the left ventricle during systole. Veins do not have a pulse as they carry low-pressure blood and have thin, less elastic walls.
Why will you sit still for five minutes before commencing measurements?
To ensure the body is in a resting state and that heart rate is not influenced by previous movement or stress.
Suggest a reason why you will measure your resting pulse rate three times.
To obtain a more accurate mean pulse rate and reduce the effect of anomalous readings.
This follows the principle of reproducibility in scientific investigations.
What do you expect to happen to your pulse rate as you increase the level of activity?
The pulse rate will increase as exercise intensity increases.
Give a reason for your answer.
Increased muscular activity requires more ATP, leading to an increase in aerobic respiration.
The heart rate increases to deliver more oxygen and glucose to muscles and remove carbon dioxide and lactic acid.
Why is it important that you take readings immediately after each stage of the investigation?
To obtain an accurate representation of pulse rate before it starts returning to resting levels due to homeostatic regulation.
What factor will you keep constant during this investigation?
Resting period before measurement (to standardize initial conditions).
Type and duration of exercise (e.g., 30 seconds of jumping jacks). Environmental conditions (temperature, stress levels, time of day).
What factor will you vary during this investigation?
Exercise intensity (e.g., walking, jogging, sprinting).
If it takes someone a long time to return to their resting pulse rate after exercise, what does this indicate about their level of fitness?
A slower recovery time suggests poor cardiovascular fitness, as the heart and lungs take longer to remove carbon dioxide and replenish oxygen levels.
Fitter individuals have a stronger myocardium (heart muscle), which pumps blood more efficiently and returns to resting levels quicker.
The average breathing rate of an adult at rest is:
12–18 breaths per minute
Complete the following by crossing out the incorrect term: When you exercise, your breathing rate is faster and is deeper.
The brain (medulla oblongata) controls breathing.
When you exercise, you make more carbon dioxide. The amount of this gas builds up in the blood, and the lungs detect the rise.
What is a pulse?
A pulse is the rhythmic expansion and recoil of an artery due to pressure surges from the contraction of the left ventricle in the cardiac cycle.
It is an indicator of heart rate (bpm) and cardiovascular efficiency.
