changes in heart rate Flashcards
improved heart rate recovery
trained individuals will return to resting HR’s faster than an untrained individual
What are the 3 main mechanisms that control the rate at which impulses are fired:
- sympathetic system
- parasympathetic system
- medulla oblongata
what is the Sympathetic System:
a part of the autonomic nervous system that speeds up heart rate
what is the Parasympathetic System:
a part of the autonomic nervous system that decreases heart rate
what is the Meduala Oblongata:
the most important part of the brain as it regulates processes that keep us alive such as breathing and heart rate
how does the heart rate know to speed up:
- the autonomic nervous system (ANS) determines the rate at which the SA Node sends out impulses
Sympathetic Nervous System and how it changes the nervous system:
- increases HR by releasing adrenaline
- adrenaline increases the strength of ventricular contraction which then increases stroke volume
- Noradrenaline aids the spread of electrical impulse throughout the heart increasing HR
- increased metabolic activity causes increased concentration of CO2 and lactic acid, decreasing pH of the blood
so the parasympathetic nervous system…
slows down the speed of heart impulses which decrease pH
Parasympathetic System and how it changes the nervous system:
- releases acetylcholine which slows the spread of impulses throughout the heart
- the results show in lower heart rate
what are receptors and what do you think they do?
the cardiac control centre is stimulated by chemoreceptors, baroreceptors and proprioreceptors
memory tools:
chemoreceptors –> increase in CO2 –> increase in heart rate
baroreceptors –> increase in blood pressure –> decrease in heart rate
proprioreceptors –> increase in muscle movement
