tegulatioj of responses during ohysical activity and sport Flashcards
How does heart rate respond to exercise intensity?
Heart rate increases with exercise; the increase depends on the intensity of the exercise. The higher the intensity, the higher the heart rate.
What is the cardiac conduction system responsible for?
The cardiac conduction system controls the flow of blood through the heart, ensuring it moves in a controlled manner from the atria to the ventricles.
What is myogenic heart muscle?
Heart muscle is described as myogenic because the beat is generated in the heart muscle itself by an electrical signal in the sinoatrial node (SAN).
What is the sequence of electrical signals in the heart?
- The sinoatrial node (SAN) sends an impulse through the walls of the atria.
- This spreads as a wave of excitation.
- This causes atrial systole (the atria to contract).
- The impulse passes to the atrioventricular node (AVN), which delays it for around 0.1 seconds.
- The impulse passes down the bundle of His to the Purkinje fibres in the ventricles.
- Ventricular systole occurs (the ventricles contract).
What is the role of the atrioventricular node (AVN)?
The AVN delays the impulse for around 0.1 seconds, allowing the atria to empty fully before the ventricles contract.
What is the role of the cardiac conduction system during exercise?
The cardiac conduction system increases heart rate to allow working muscles to receive more oxygen.
What are the two main types of nervous system control over heart rate?
The sympathetic and parasympathetic systems.
What is the function of the sympathetic nervous system?
It prepares the body for exercise, often referred to as the ‘fight or flight response.’
What is the function of the parasympathetic nervous system?
It relaxes the body and slows down high-energy functions, described as ‘rest and relax.’
What hormone is secreted by the adrenal gland to increase heart rate?
Adrenaline.
What is an anticipatory rise in heart rate?
An increase in heart rate prior to exercise due to adrenaline release in anticipation of activity.
What does neural regulation involve?
It involves the sympathetic and parasympathetic nervous systems.
What does chemical regulation involve?
It involves the levels of oxygen, carbon dioxide, and pH in the blood.
Where is the cardiac control centre located?
In the medulla oblongata of the brain.
What is the importance of the medulla oblongata?
It regulates processes that keep us alive.
