WK 3: Arterial pressure and its control

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What is the response to a fall in arterial pressure in the baroreflex mechanism?

Decrease in heart rate and sympathetic vasoconstrictor drive
No change in heart rate and sympathetic vasoconstrictor drive
Increase in heart rate and sympathetic vasoconstrictor drive (correct)
Total cessation of heart activity and sympathetic vasoconstrictor drive

Where are the arterial baroreceptors located?

Spinal cord and peripheral nerves
Medulla oblongata and pons
Cerebrum and cerebellum
Carotid sinus and aortic arch (correct)

What is the effect of an increase in arterial pressure on arterial baroreceptors?

Total cessation of firing
No change in frequency of firing
Decrease in frequency of firing
Increase in frequency of firing (correct)

What is the role of the nucleus tractus solitarius (NTS) in the baroreflex mechanism?

It receives projections from arterial baroreceptors (D) Signup and view all the answers

What is the effect of the baroreflex on heart rate?

It decreases heart rate in response to an increase in arterial pressure (D) Signup and view all the answers

What is the role of the caudal ventrolateral medulla (CVLM) in the baroreflex mechanism?

It sends inhibitory projections to the RVLM (C) Signup and view all the answers

What is the type of nervous system involved in the baroreflex mechanism?

Parasympathetic nervous system (B) Signup and view all the answers

What is the primary function of the arterial baroreflex and cardiac baroreflex?

To maintain a relatively constant blood pressure (B) Signup and view all the answers

What is the main site of peripheral resistance in the body?

Arterioles (A) Signup and view all the answers

What is the role of baroreceptors in the arterial baroreflex and cardiac baroreflex?

To sense changes in blood pressure (C) Signup and view all the answers

What is the effect of the parasympathetic nervous system on heart rate?

Decreases heart rate (C) Signup and view all the answers

What is the pathway of the arterial baroreflex?

Baroreceptors - NTS - CVLM - RVLM - MSNA (B) Signup and view all the answers

What is the average pressure over the cardiac cycle?

Mean arterial pressure (C) Signup and view all the answers

What is the reason for the difference in blood pressure between lying down and standing?

Hydrostatic pressure (C) Signup and view all the answers

What is the principle behind the baroreflex mechanism that controls arterial pressure?

Negative feedback (B) Signup and view all the answers

What activates cardiac vagal neurons in response to an increase in arterial pressure?

NTS (A) Signup and view all the answers

What is the effect of increased parasympathetic activity on the heart?

Decreased heart rate and force of contraction (B) Signup and view all the answers

What is the effect of decreased sympathetic vasoconstrictor activity on arterioles?

Vasodilation (A) Signup and view all the answers

What is the response to a fall in arterial pressure?

Increased vasoconstrictor drive (A) Signup and view all the answers

Which of the following is NOT involved in the baroreflex mechanism?

Cerebral cortex (D) Signup and view all the answers

What is the function of baroreceptors?

Detection of changes in arterial pressure (C) Signup and view all the answers

What is the primary effect of sympathetic vasoconstriction on arterioles?

Increased total peripheral resistance (C) Signup and view all the answers

What is the role of nitric oxide in the regulation of blood pressure?

It counteracts neurally-mediated vasoconstriction (B) Signup and view all the answers

What is the function of the baroreflex mechanism?

To maintain a constant blood pressure (B) Signup and view all the answers

What is the effect of pharmacological blockade of NO production on mean BP?

An increase of ~20 mmHg (B) Signup and view all the answers

Which of the following is NOT a target of sympathetic vasoconstriction?

Brain (A) Signup and view all the answers

What is the primary neurotransmitter released by sympathetic nerve terminals to cause vasoconstriction?

Norepinephrine (B) Signup and view all the answers

What is the effect of an increase in blood pressure on the baroreflex mechanism?

It stimulates a decrease in blood pressure (D) Signup and view all the answers

Which of the following is NOT a component of the baroreflex mechanism?

Pons (B) Signup and view all the answers

What is the primary function of the parasympathetic nervous system in the context of blood pressure regulation?

To decrease blood pressure (D) Signup and view all the answers