Nervous Regulation of the Circulation

Question 1

What is the primary nervous system that regulates circulation?

Answer 1

sympathetic nervous system

Question 2

What nervous system assists in regulation of heart function?

Answer 2

parasympathetic nervous system

Question 3

Where do the sympathetic vasomotor nerves leave the spinal cord?

Answer 3

through thoracic and 1st 1 or 2 lumbar spinal nerves

Question 4

The SNS innervates all blood vessels except what?

Answer 4

• capillaries
• precapillary sphincters
• metarterioles

Question 5

Stimulation of the SNS does what to the volume of veins?

Answer 5

decreases

Question 6

SNS innervation of small arteries and arterioles allows for what?

Answer 6

vasoconstriction

Question 7

What is the condition called in which blood vessels are inadequately filled and blood can’t circulate normally?

Answer 7

circulatory shock

Question 8

What causes hypovolemic shock?

Answer 8

losing blood volume

Question 9

What causes vascular shock?

Answer 9

extensive massive vasodilation of the vessels (possibly caused by drugs or an allergic reaction)

Question 10

What causes cardiogenic shock?

Answer 10

the heart stops working – pump failure (caused by some kind of myocardial damage to the muscle of the heart)

Question 11

What is a massive bacterial infection that travels throughout the blood?

Answer 11

septicemia

Question 12

Do SNS nerves carry more vasoconstrictor fibers or vasodilator fibers?

Answer 12

vasoconstrictor fibers

Question 13

Vasoconstrictor fibers are largely distributed where?

Answer 13

• kidneys
• intestines
• spleen
• skin

Question 14

Where is the vasomotor center found?

Answer 14

brainstem

Question 15

What 3 area are found in the vasomotor center?

Answer 15

• vasoconstrictor area
• vasodilator area
• sensory area

Question 16

What does the sympathetic vasoconstrictor tone maintain?

Answer 16

• normal vasomotor tone

- blood pressure

Question 17

The vasoconstrictor area secretes what?

Answer 17

norepinephrine

Question 18

Function of the vasodilator area?

Answer 18

inhibits the vasoconstrictor area

Question 19

What 2 nerves innervate the vasomotor center?

Answer 19

• vagus

- glossopharyngeal

Question 20

What does the adrenal medulla secrete when stimulated by the SNS?

Answer 20

norepinephrine and epinephrine –> causing vasoconstriction

Question 21

Function of the cardiac center?

Answer 21

adjusts rate and force of heart contraction to meet needs of the body

Question 22

What 2 centers are included in the cardiac center?

Answer 22

• cardioaccelerator center

- cardioinhibitory center

Question 23

What nervous system controls the cardioacceleratory center?

Answer 23

SNS

Question 24

What nervous system controls the cardioinhibitory center?

Answer 24

PSNS

Question 25

What 3 changes do you need to cause in increase in arterial pressure?

Answer 25

- most arterioles constrict - veins and other large vessels constrict - SNS stimulation of heart

Question 26

An increase in arterial pressure simultaneously stimulates what two centers?

Answer 26

- vasoconstrictor | - cardioaccelerator

Question 27

Baroreceptors respond to what?

Answer 27

changes in pressure in the blood vessels - respond to stretch or lack of stretch in vessel walls ex: tells the brain to vasodilate if blood pressure is too high

Question 28

Chemoreceptors respond to what?

Answer 28

- changes in O2, CO2, and H+ | - -> will signal the brainstem to vasodilate/vasoconstrict depending on blood gas

Question 29

Chemoreceptors are located where?

Answer 29

carotid bodies and aortic bodies

Question 30

Where are baroreceptors located?

Answer 30

- carotid sinuses - aortic arch - walls of nearly every large artery in the neck and thorax

Question 31

Chemoreceptors stimulate what?

Answer 31

nerve fibers traveling to the vasomotor center

Question 32

atrial reflexes respond to what?

Answer 32

change in pressure (stretch receptors)

Question 33

How does the body respond to cerebral ischemia?

Answer 33

- strong reaction of vasoconstrictor and cardioaccelerator centers - large rise in systemic arterial pressure - increases MAP to ~250mmHg

Question 34

What causes cerebral ischemia?

Answer 34

- blood flow to vasomotor center severely decreases

Question 35

What is the most powerful activator of SNS vasoconstrictor system?

Answer 35

cerebral ischemia

Question 36

What does SNS do to fix cerebral ischemia?

Answer 36

restores BP by increasing HR and TPR