PSNS Control of F(h)

Question 1

What does intrinsic mean?

Answer 1

• internal (autorhythmic + myogenic input only)

Question 2

What sets heart rate?

Answer 2

• pacemaker cells

Question 3

What is intrinsic heart rate determined by?

Answer 3

• blocking adrenergic and cholinergic receptors

Question 4

What is Q10 of intrinsic heart rate?

Answer 4

~2.0

Question 5

What is extrinsic control?

Answer 5

• external to heart (PSNS + SNS)

Question 6

What is extrinsic control determined by?

Answer 6

• push-pull modulation (adrenergic vs cholinergic tone)

Question 7

What suppresses F(h) externally?

Answer 7

• inhibitory cholinergic tone (PSNS vagus)

Question 8

What 4 factors cause inhibitory cholinergic tone?

Answer 8

• hypoxia
• burst swimming (dec. Q and F(h)
• visual/olfactory stimuli
• cold temp accumulation