What would be the change in the heart that occurs during excersise?
What is going to pick up and increase in heart rate and blood pressure?
What is going to bring it back to homeostasis?
During exercise, several changes occur in the heart to meet the increased demand for oxygen and nutrients by the muscles. The changes include:
1. Increased heart rate: The heart rate increases to pump more blood to the working muscles. This is achieved through an increase in the firing rate of the sinoatrial (SA) node, which initiates each heartbeat.
2. Increased stroke volume: The amount of blood ejected by the heart with each contraction, known as stroke volume, increases during exercise. This is due to an increase in the strength of each heartbeat, which allows the heart to pump more blood with each contraction.
3. Increased cardiac output: Cardiac output, which is the amount of blood pumped by the heart per minute, increases during exercise. It is calculated by multiplying the heart rate by the stroke volume.
4. Vasodilation: The blood vessels supplying the muscles dilate during exercise to increase blood flow to those areas. This helps deliver more oxygen and nutrients to the working muscles.
As for the factors that pick up and increase heart rate and blood pressure, the primary contributors are the sympathetic nervous system and the release of adrenaline (epinephrine). The sympathetic nervous system stimulates the SA node to increase heart rate, while adrenaline causes vasoconstriction, which raises blood pressure.
To bring the heart rate and blood pressure back to homeostasis after exercise, the parasympathetic nervous system plays a crucial role. The parasympathetic system releases acetylcholine, which inhibits the SA node and slows down the heart rate. Additionally, after exercise, the blood vessels return to their normal state of constriction (vasoconstriction) by the end of the activity, helping to regulate blood pressure and maintain homeostasis.