AND ANSWERS
how does body metabolism increase in someone with a high fever, compared to someone running a
marathon? - CORRECT ANSWER✅✅✅A person with an extremely high fever (approaching lethality)
shows a body metabolism increase of 100% above normal.
In comparison, metabolism of the body during a marathon may increase to 2000% above normal.
describe what exercise does to homeostasis - CORRECT ANSWER✅✅✅Initially, exercise disrupts
homeostasis (maintenance of a constant internal environment) - this is because exercise is a significant
stress on the human body.
what does exercise often require, in terms of the systems of the body? - CORRECT
ANSWER✅✅✅exercise often requires prolonged coordination among most body systems (muscular,
skeletal, nervous, circulatory, respiratory, urinary, skin, endocrine)
provide some values for someone at rest compared to someone in maximal exercise for the following
cardiovascular parameters, giving comments on the reasonings if necessary:
- heart rate
- stroke volume
- cardiac output
- systolic pressure
- diastolic pressure - CORRECT ANSWER✅✅✅- heart rate: rest = 70 bpm, max exercise = 200 bpm
(REMEMBER, maximum HR = 220 - age (in years))
- stroke volume: rest = ~70 ml, max exercise = ~130 ml
- cardiac output: rest = 5 litres/min, max exercise = 25 litres/min (there is an increased demand for
oxygen during exercise, so the heart must increase cardiac output to supply the involved tissues)
- systolic pressure: rest = 120 mmHg, max exercise = 180 mmHg
- diastolic pressure: rest = 80 mmHg, max exercise = 70 mmHg (diastolic pressure rarely changes during
exercise, but if it does, it only ever decreases - NEVER INCREASES)
, what happens to cardiac output during exercise, and what is this increase proportional to? what is the
equation for cardiac output? - CORRECT ANSWER✅✅✅During exercise, CO can increase to 20-25
l/min (~40 l/min in trained athletes during heavy endurance type exercise)
CO increases in proportion to work load
CO = HR × SV
what coordinates control of heart rate? - CORRECT ANSWER✅✅✅the cardiovascular control centre
in the brain stem
what is the immediate response of heart rate to an individual starting exercise, and explain what makes
this happen - CORRECT ANSWER✅✅✅An immediate response to exercise is an increase in HR to
deliver more oxygenated blood to the exercising muscles.
REASON:
When individual starts to exercise, there is an anticipatory response driven by a central command from
the CNS to increase sympathetic activity and decrease parasympathetic activity - this drives an increase
in heart rate at the very start of exercise.
what is an increase in heart rate proportional to? - CORRECT ANSWER✅✅✅HR increases in
proportion to work load (greater workload = greater HR)
what can a long-term adaptation to a regular exercise programme result in? - CORRECT
ANSWER✅✅✅can lead to increasing the strength and efficiency of your cardiovascular system
describe intrinsic control of stroke volume - CORRECT ANSWER✅✅✅- it is related to end diastolic
volume (volume of blood in ventricles when ventricles are relaxed (ie max volume in ventricles) and so
therefore it is related to blood returning back to the heart
- skeletal muscles act as pumps, where muscular contraction compresses veins so increases blood flow
back to the heart
- venoconstriction also contributes to blood flowing back to the heart, as it is triggered by an increase in
sympathetic stimulation and any extra blood stored in the veins returns to the heart