effect of exercise on heart rate Flashcards
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how is heart rate measured?
by counting the number of times a heart beats in a minute
what is the natural resting heart rate controlled by?
a group of cells in the right atrium called the pacemaker
what is the role of the pacemaker?
to coordinate the contraction of the heart muscle and regulate the heart rate
what do pacemaker cells send out?
electrical impulses which initiate a contraction in the cardiac muscle
what other factors can affect our heart rate?
adrenaline
why does the heart pump blood around the body?
to supply oxygen & glucose to respiring cells
what does blood also do for respiring cells?
removes waste products from respiring cells
when we exercise, what does our body need more of?
our muscles need more glucose & oxygen for aerobic respiration
why does our heart rate increase?
so that more blood travels to the muscles
what are changes in heart rate controlled by?
nerve impulses from a part of the brain called the medulla
what happens when we exercise?
the muscles produce more CO2 in aerobic respiration
what sensors detect this increase in CO2?
sensors in the aorta and carotid artery
what do the sensors in the aorta and carotid artery do?
they send nerve impulses to the medulla
how does the medulla respond to these nerve impulses?
sends nerve impulses along the accelerator nerve
what does the accelerator nerve do?
increases the heart rate
