control of heart rate

Question 1

what does an increase in exercise lead to

Answer 1

more co2 lower pH
detected by chemoreceptors in the walls of the aorta and carotid arteries
increases frequency of impulses to medulla which causes increase in frequency of impulses to SAN via the sympathetic nerve
SAN increases frequency of impulses speeding up the heart rate
(same happens with decreased CO2 but higher pH and parasympathetic ns used instead

Question 2

describe the response to increase in blood pressure on the heart

Answer 2

detected by baroreceptors in walls of carotid arteries and aorta
increase frequency of impulses to medulla oblongata which will increase frequency of impulses via the parasympathetic nervous system to the SAN in the heart
SAN decrease frequency of impulses slowing the heart rate
same will happen with reduced blood pressure but the sympathetic ns used instead