question 17.) What two factors determine the pressure in any blood vessel ? 

a.the amount of blood in the blood vessel and its function 

b.the size of the blood vessel and the amount of blood in the blood vessel

c.the size of the blood vessels and its location 

d.none of the above 

3 points  

QUESTION 18

1. Which of the following conditions at the S-A node will cause a decrease in heart rate? 
2. Increased sodium permeability 
3. Decreased acetylcholine levels 
4. Increased norepinephrine levels 
5. Increased potassium permeability 

3 points  

QUESTION 19

1. What effect does atropine have on heart rate.
2. a.decrease
3. b.increase
4. c.both
5. d.none of the above

3 points  

QUESTION 20

1. Which of the following conditions at the S-A node will cause a decrease in heart rate? 
2. Increased sodium permeability 
3. Decreased acetylcholine levels 
4. Increased norepinephrine levels 
5. Increased potassium permeability 

QUESTION 21

Which of the following junctiomal proteins are located between cardiomyocytes?

a.tight junctions

b.gap junctions

c.desmosomes

d.hemidesmosomes

e.none of the above