Baroreceptors in carotid artery and aorta detect high BP - action potentials are sent to the medulla - increases frequency of action potentials along the parasympathetic neurone to the SA node - decreases rate of electrical impulses- slows heart rate
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How does low blood pressure affect heart rate?
Baroreceptors detect low BP - sends action potentials to medulla - increases frequency of action potentials along sympathetic neurone to SA node - increases rate of electrical impulses - increases heart rate
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How does exercise affect heart rate?
Increase in CO2 production dissolves in blood - increases pH - chemoreceptors detect - sends action potentials to medulla - increases frequency of action potentials along sympathetic to SA node - speeds up rate
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What is a 'resting potential'?
The potential difference across a cell membrane when the cell is at rest
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(1) How is the resting potential maintained? (Hint: Pump)
Through the movement of sodium and potassium ions. Na-K pumps use active transport to three Na+ out and two K+ into the neurone
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(2) How is the resting potential maintained? (Hint: K+)
Potassium ion channels allow facilitated diffusion of potassium ions out of the neurone down their concentration gradient
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How does a stimulus generate an action potential?
Na+ channels open.Na+ diffuse into the neurone, making it less negative. If the threshold is reached, more Na+ channels open.
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Other cards in this set
Card 2
Front
What part of the heart is known as the 'pacemaker'?
Back
Sinoatrial Node
Card 3
Front
How does the pacemaker of the heart control heart rate?
Back
Card 4
Front
Where does the electrical activity travel to from the pacemaker?
Back
Card 5
Front
What happens when electrical activity reaches the AV node?
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