Control Of Heart Rate Flashcards

1
Q

What does the SA mode send impulses across?

A

The atria

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2
Q

When impulses pass across the cardiac muscle what does this cause?

A

Muscle contraction (increasing the pressure)

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3
Q

Why is impulse delayed at AV node?

A

To give time for the atria to empty completely of blood before ventricles contract

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4
Q

What prevents the atria and ventricles from contracting at the same time?

A

A layer of non conducting tissue

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5
Q

Describe the passage of impulses from the AV node to cause ventricles to contract

A

Down the bundle of His to the apex of the heart then around the purkyne fibres

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6
Q

What type of receptions detect a change in pH and what causes that change in pH?

A

Chemoreceptors. pH change caused by increase or decrease of carbon dioxide in blood

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7
Q

What type of receptors detect a change in blood pressure?

A

Baroreceptors

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8
Q

Where are the receptors found?

A

Aortic arch (aorta) and carotid artery

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9
Q

Where in the brain do these receptors send impulses to?

A

Medulla

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10
Q

Which pathway does the medulla send impulses down to decrease heart rate and what neurotransmitter does this release to the SA node?

A

Parasympathetic pathway releasing acetylcholine

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11
Q

Which pathway does the medulla send impulses down to increase heart rate and what neurotransmitter does this release to the SA node?

A

Sympathetic pathway releasing noradrenaline

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12
Q

What happens to the frequency of impulses sent from the SA node to increase heart rate?

A

Increases causing heart to contract more frequently and increasing heart ratw

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