6.1.3 Control of HR Flashcards
What does the SAN sending a wave of electrical impulses to the AVN cause?
Atrial contraction
What is the purpose of non-conducting tissue?
Prevents electrical impulses reaching the ventricles, preventing the immediate contraction of ventricles
What does the AVN sending electrical impulses down the Bundle of His and Purkinje fibres cause?
Ventricles to contract from base-up
How is the impact of heavy exercise controlled by the cardiac cycle?
Rate of aerobic respiration increases, producing more carbon dioxide, lowering blood pH. Chemoreceptors in carotid artery detect the decrease in blood pH and send a wave of electrical impulses to the medulla. The medulla sends more electrical impulses to the SAN, via the sympathetic nervous system. More waves of electrical impulses are sent from SAN to AVN.
If heart rate was to increase, down what autonomic nervous system would waves of electrical impulses be sent down?
Sympathetic
If heart rate was to decrease, down what autonomic nervous system would waves of electrical impulses be sent down?
Parasympathetic
What receptors detect blood pH and where are they located?
Chemoreceptors in the carotid artery
What part of the brain controls nervous activity as part of the cardiac cycle?
Medulla
How does high blood pressure impact heart rate and the cardiac cycle?
Baroreceptors in the carotid artery detect the high blood pressure. Baroreceptors send waves of electrical impulses to the medulla. The medulla sends more waves of electrical impulses to the SAN, via the parasympathetic nervous system. Less waves of electrical impulses are sent from the SAN to the AVN.
What receptors detect blood pressure and where are they located?
Baroreceptors in the carotid artery
What nervous systems are contained in the autonomic nervous system?
Sympathetic and parasympathetic
The control of the cardiac cycle is regulated by which nervous system?
Autonomic
