Exam #2: Regulation of Blood Pressure II

Question 1

What is the NTS?

Answer 1

Nucelus tractus solitarius=

• Bilateral structure
• Receives all input from sensory receptors
• Sends projects to cardio-inhibitory center & vasomotor center

Question 2

What is the RVLM?

Answer 2

Rostroventral Lateral Medulla

• Vasoconstrictor center
• Sympathetic outflow stops here on its way out of the spinal cord

*Excitation leads to vasoconstriction via the SNS

Question 3

What is the CVLM?

Answer 3

Caudoventral Lateral Medulla

• Vasodilator center
• Inhibits the RVLM

*Excitation leads to vasodilation by inhibiting the RVLM

Question 4

What two nuclei form the cardio-inhibitory center? Which division of the ANS are these two nuclei associated with?

Answer 4

1) Dorsal motor nucleus of the vagus (DNMV)
2) Nucleus ambiguus

PNS; thus, excitation leads to slowing the heart rate

Question 5

Draw the overview of the reflex arcs.

Answer 5

N/A

Question 6

Outline the steps in the PNS reflex arc in response to an increase in HR.

Answer 6

1) Increased heart rate
2) Sensory input
3) NTS
4) DMNV & NA
5) Vagus
6) Decreased HR

Question 7

Outline the steps in the SNS reflex arc.

Answer 7

1) Sensory input
2) NTS
3) CVLM
4) RVLM
5) IML
6) Sympathetic Chain
7) Effector

Question 8

Where are sensory receptors located?

Answer 8

1) Aorta (pressure and oxygen saturation)
2) Carotid arteries (pressure & oxygen saturation)

Baroreceptors detect changes in pressure
Chemoreceptors detect changes in oxygen saturation

Question 9

What are the reflexes that control blood pressure?

Answer 9

1) Arterial baroreflex
2) Cardiopulmonary baroreflex
3) Chemoreflex

Question 10

What are the characteristics of the arterial baroreflex?

Answer 10

Activated by HIGH pressure
Sensors are in the carotid sinus & aortic arch
Mechanosensitive
Short-term

Question 11

What are the characteristics of the cardiopulmonary baroreflex?

Answer 11

Activated by LOW pressure i.e. low volume
Sensors in the atria & pulmonary vessels
Mechanosensitive

Question 12

What are the characteristics of the chemoreflex?

Answer 12

Central & peripheral receptors
Chemosensitive (O2, Co2, & pH)

• Peripheral input changes sympathetic tone & vasoconstriction
• Central also leads to changes in sympathetic tone/ vasoconstriction BUT also changes hemodynamics in the brain i.e. CO to brain (arteriole resistance)

Question 13

Draw the arterial baroreflex in regards to the SNS & an increase in blood pressure.

Answer 13

N/A

1) Stretch vessel wall
2) Increase BR firing
3) Signal to NTS (via vagus or glossopharyngeal)
4) Inhibition of vasoconstrictor center & activation of cardioinhibitory center
5) Vasodilation of vessels, decrease HR, decrease contractility

Question 14

Draw the arterial baroreflex in regards to the PNS & and increase in blood pressure.

Answer 14

N/A

1) Increased blood pressure sensed
2) Efferents stimulate NTS
3) DMNV & NA activated
4) Increased vagal outflow
5) Decreased heart rate
6) Decreased CO

Question 15

What happens to the arterial baroreflex in HTN?

Answer 15

Baroreflex resetting

Question 16

Draw the chemoreflex arch.

Answer 16

N/A

1) Decreased arterial blood pressure
2) Decreased O2, increased CO2, & increased H+ sensed
3) Increased CR firing
4) Signal to CNS
5) Activation of vasoconstriction center
6) Vasoconstriction of blood vessels

Note that the brain has its own chemoreceptors that will affect these.

Question 17

Draw the Cardiopulmonary reflex.

Answer 17

N/A

1) Decreased blood volume
2) Decreased stretch on atria
3) Increased firing to CNS

Question 18

Resp oscillations in blood pressure

Answer 18

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Question 19

How is blood pressure regulated in the long-term?

Answer 19

Kidneys

Question 20

How do the kidneys regulate blood pressure?

Answer 20

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Question 21

What is pressure diuresis?

Answer 21

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Question 22

What is pressure natriuresis?

Answer 22

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Question 23

Draw the renal output curve.

Answer 23

N/A

Question 24

Draw the systemic renin-angiotensin system.

Answer 24

N/A