3.8 -- Blood Pressure Regulation

Question 1

What four factors affect blood pressure?

Answer 1

Heart rate, total peripheral resistance, stroke volume, and blood volume

Question 2

What does an increase in total peripheral resistance, heart rate, stroke volume, or blood volume do to blood pressure?

Answer 2

Increase blood pressure

Question 3

Vasoconstriction of arterioles raises or decreases blood pressure upstream in the arteries?

Answer 3

Raises blood pressure

Question 4

What is the equation for arterial blood pressure?

Answer 4

Cardiac output x total peripheral resistance

Question 5

What is mean arterial pressure?

Answer 5

Average pressure in the arteries in one cardiac cycle

Question 6

Mean arterial pressure - venous return is what?

Answer 6

Driving force for blood flow into capillaries

Question 7

What is the equation for mean arterial pressure?

Answer 7

Diastolic BP + 1/3rd pulse pressure

Question 8

Constriction does what to the pressure on the leading and following side?

Answer 8

Increase pressure on the leading side, decrease pressure on the following side

Question 9

Kidneys can control blood pressure, therefore also controlling what?

Answer 9

Stroke volume

Question 10

Kidneys are largely under what control?

Answer 10

Hormonal

Question 11

Kidneys under hormonal control take a long time, which is most important for what control of blood pressure regulation?

Answer 11

Long-term control

Question 12

Sympathoadrenal system acutely stimulates what of arterioles, raising TPR and increased cardiac output? This can occur minute to minute.

Answer 12

Vasoconstriction

Question 13

What is the baroreceptor reflex activated by?

Answer 13

Changes in blood pressure detected by the baroreceptors (stretch reflex) in the aortic arch and carotid artery

Question 14

Does increased or decreased blood pressure stretch these receptors, increasing the action potentials to the vasomotor and cardiac control centers in the medulla?

Answer 14

Increased blood pressure

Question 15

Baroreceptor reflexes are most sensitive to drops in what?

Answer 15

Blood pressure

Question 16

The vasomotor center controls what nerves for vasoconstriction and dilation?

Answer 16

Autonomic nerves

Question 17

The cardiac center controls what?

Answer 17

Heart rate

Question 18

The three structures of baroreceptor reflexes are the baroreceptors, vasomotor/cardiac control centers in medulla, and sympathetic/parasympathetic axons to the heart and blood vessels.

Which is an effector, an integrating center, and sensor?

Answer 18

Baroreceptors – Sensor
Vasomotor/cardiac control centers in medulla – Integrating center
Sympathetic/parasympathetic axons to the heart and blood vessels – Effector

Question 19

The baroreceptors at the carotid artery and aortic arch sense blood pressure and fire what to the brain through afferent neurons?

Answer 19

Action potentials

Question 20

Then, the brain integrates then activates autonomic neurons to influence the heart in what two ways? What about the way to influence vascular smooth muscle contraction?

Answer 20

Heart – Heart rate (Pacemaker) and contractility
Vascular Smooth Muscle: Total peripheral resistance

Question 21

As mean arterial pressure rises, do the action potentials frequency to the brain increase or decrease?

Answer 21

Increase

Question 22

Mean arterial pressure is normally around what number?

Answer 22

93 mmHg

Question 23

Less action potentials received at the brain will turn up sympathetic NS to increase what?

Answer 23

Blood pressure

Question 24

The baroreceptor reflex is good for what regulation like going from laying down to standing?

Answer 24

Quick beat-by-beat regulation

Question 25

A fall in blood pressure leads to what two effects on the sympathetic and parasympathetic activity? What does this do to total peripheral resistance and heart rate?

Answer 25

Sympathetic -- Increases Parasympathetic -- Decreases Total Peripheral Resistance -- Increases Heart Rate -- Increases

Question 26

What function of the baroreceptor control system prevents wide, moment-moment swings in pressure?

Answer 26

"Buffer" function

Question 27

Baroreceptors reset themselves to whatever pressure they're exposed to for how long?

Answer 27

1-2 days

Question 28

Are baroreceptors important for short-term or long-term regulation and control of arterial pressure?

Answer 28

Short-term

Question 29

What controls plasma volume?

Answer 29

Kindeys

Question 30

What is the key to long-term regulation of arterial pressure?

Answer 30

Kidneys