Circulation: Regulation

Question 1

For acute control of tissue metabolism, what is being compared?

Answer 1

Blood flow to rate of metabolism

Question 2

For acute control of tissue metabolism, an increase in metabolism by 8x increases the blood flow by how much?

Answer 2

4x

Question 3

The availability of oxygen to the tissues decrease when…?

Answer 3

1. High altitude
2. Pneumonia
3. CO poisoning
4. Cyanide poisoning

Question 4

For acute control of oxygen availability, what is being compared?

Answer 4

Blood flow to arterial oxygen saturation

Question 5

For acute control of oxygen availability, if arterial pressure drops to 25% of normal value, what happens to blood flow?

Answer 5

Increases 3x

Question 6

(Increase/decrease) of oxygen availability and (increase/decrease) metabolism can induce the formation of vasodilator substances

Answer 6

Decrease oxygen

Increase metabolism

Question 7

Acute vs long-term control, which provides even better control of flow in proportion to the needs of the tissues?

Answer 7

Long-term control

Question 8

How does nitroglycerin work?

Answer 8

Forms free radical nitric oxide (which relaxes). Increase cGMP, dephosphorylation of myosin chain and results in vasodilation

Question 9

Endothelin is a vaso-(dilator/constrictor)

Answer 9

vasoconstrictor

Question 10

When does endothelin increase in someone’s body?

Answer 10

When vessels are injured

Question 11

Norepi
Histamine
Angiotensin II
Epinephrine
Bradykinin
Vasopressin

Which are vasoconstrictors and vasodilators

Answer 11

Vasoconstrictors

Norepi, Epi, Angiotensin II, and Vasopressin

Vasodilators

Bradykinin + Histamine

Question 12

Where is renin produced?

Answer 12

Kidney

Question 13

Where is angitensinogen produced?

Answer 13

Liver

Question 14

Angiotensin I is physiologically (active/inert)

Answer 14

inert

Question 15

What allows angiotensinogen to form angiotensin I?

Answer 15

Renin

Question 16

What allows angiotensin I to form angiotensin II?

Answer 16

ACE (angiotensin converting enzyme)

Question 17

What routes can angiotensin II take?

Answer 17

1. Inactivated
2. Aldosterone
3. Angiotensin receptor

Question 18

What enzyme would inactivate angiotensin II?

Answer 18

Angiotensinase

Question 19

With aldosterone, what happens?

Answer 19

Increase reabsorption of Na+ and water, increase blood volume and increase BP

Question 20

With angiotensin receptors activated, what happens?

Answer 20

Vasoconstriction, then increase BP

Question 21

Ca2+ causes (vasoconstriction/vasodilation)

Answer 21

vasoconstriction

Question 22

K+ causes (vasoconstriction/vasodilation)

Answer 22

vasodilation

Question 23

Mg2+ causes (vasoconstriction/vasodilation)

Answer 23

vasodilation

Question 24

CO2 causes (vasoconstriction/vasodilation)

Answer 24

vasodilation in most tissues, but dilates especially in the brain

Question 25

Innervation of (small/large) vessels increase resistance to blood flow

Answer 25

small

Question 26

Innervation of (small/large) vessels push blood to heart thus increasing blood volume in chambers

Answer 26

large

Question 27

What nerve carries parasympathetic signals to the heart?

Answer 27

Vagus nerve

Question 28

When blood pressure drops, baroreceptors are (stimulated/inhibited)

Answer 28

inhibited

Question 29

When blood pressure increases, baroreceptors are (stimulated/inhibited)

Answer 29

stimulated

Question 30

When blood pressure goes down, what is the short term solution?

Answer 30

Baroreceptor reflex

Question 31

When blood pressure goes down, what is the long-term regulation?

Answer 31

Using renin

Question 32

What is the primary purpose of arterial baroreceptor system?

Answer 32

Reduce minute-by-minute variation in arterial pressure

Question 33

When is the chemoreceptor reflex important?

Answer 33

When arterial pressure falls below 80mm Hg