Describe how the heart rate changes
and how it is regulated by neural, hormonal and intrinsic factors.
Neural Factors
Hormonal Factors
Chemical Factors
Heart rate during exercise
Heart rate increases to meet the demand of the exercise
There is a maximum point in the HR 220-age of athlete
Heart rate increase to supply active muscle with oxygen and remove waste products
waste products are carbon dioxide and lactic acid
heart rate steadily increases until it reaches maximum in which it will plateau
Heart rate is controlled by the nervous system
There are two branches of the nervous system, parasympathetic system & the sympathetic system
The nervous system is stiumlated by changes detected from the receptors
Chemoreceptors
Proprioceptors
Baroreceptors
The cardiac control center is located in the medulla oblongata which controls the rate of breathing via the nervous system
Adrenaline is the hormone released at the onset of exercise
Adrenaline stiumlates the SA node
This increases HR to provide more oxygen to the working muscles.
as exercise increase there is an increase in carbon dioxide in the blood
Chemoreceptors detect carbon dioxide in the blood, which then stimulates the sympathetic nervous system
This increase HR and reduce blood acidity