Regulation of Arterial Pressure - Ballam

Question 1

2 Methods of control of arterial pressure

Answer 1

1. rapid baroreceptor reflex

2. slower hormonal mediated

Question 2

Baroreceptor reflex

Answer 2

Negative feedback
Responds to a change in arterial pressure by invoking processes to return to original level
Acts within seconds and last indefinitely
Both short and long term compared to long term hormone control

Question 3

When metabolic demand is high

Answer 3

More blood is released through capillary beds by reducing resistance of arterioles

Question 4

Baroreceptor location

Answer 4

Carotid sinus

Aortic arch

Question 5

Baroreceptors and firing rate

Answer 5

Increase firing rate in response to increasing vascular wall stretch
Decrease firing rate when pressure falls

Question 6

Baroreceptors send input to the control center in the medulla called the

Answer 6

Vasomotor center

Question 7

Vasomotor Center

Answer 7

Clusters of cells responsible for acting via outputs traveling either in the parasympathetic (vagus) nerve or the symp nerves

Question 8

Main parasympathetic nerve

Answer 8

Vagus

Question 9

Increased firing of baroreceptors and symp/para outflow

Answer 9

Decreases sympathetic outflow

Increases parasympathetic outflow

Question 10

Decreased firing of baroreceptors and symp/para outflow

Answer 10

Increases symp outflow

Decreases parasymp outflow

Question 11

Equation

BP =

Answer 11

CO x TPR

Question 12

Equation

CO =

Answer 12

SV x HR

Question 13

Stroke volume dependent on

Answer 13

Sympathetic stimulation of heart

Preload

Question 14

HR dependent on

Answer 14

Symp and parasymp stimulation

Question 15

TPR dependent on

Answer 15

Sympathetic stimulation of arterioles

Question 16

Sympathetic causes

Answer 16

Constriction of arterioles and veins - alpha
Increases contractility - beta1
Fluid retention by kidneys
Increases secretion

Question 17

Parasympathetic causes

Answer 17

A decrease of heart rate (muscarinic receptors)

Question 18

Sympathetic and kidneys

Answer 18

Sympathetic system causes fluid retention by kidney due to afferent arteriolar constriction and increased renin secretion

Question 19

Renin

Answer 19

Enzyme secreted by kidney into bloodstream in response to a drop in BP
Causes angiotensinogen to be converted to angiotensin I in blood

Question 20

If BP higher than normal, how much renin is secreted?

Answer 20

Less

Question 21

Angiotensin I

Answer 21

Converted to angiotensin II in lungs by ACE to begin the compensation mechanism

Question 22

Afferent in kidneys means

Answer 22

Towards glomerulus

Question 23

Juxtaglomerular cells

Answer 23

In walls of renal afferent arterioles

Renin production in response to low BP and in response to sympathetic stimulation

Question 24

Angiotensin II

Answer 24

Causes secretion of aldosterone from adrenal cortex
Acts directly on kidney to increase sodium and water
Increases thirst
Stimulates secretion of antidiuretic hormone (ADH)
Causes global vasoconstriction of arterioles via specific receptors