Unit 4 - Cardiovascular Interactions and Responses

Question 1

What does this diagram represent?

Answer 1

the central venous pressure vs cardiac output

Question 2

As cardiac output increases, what happens do central venous pressure?

Answer 2

it decreases

Question 3

What happens when the curve goes vertical?

Answer 3

the increase in cardiac output causes venous collapse

Question 4

What does this diagram represent?

Answer 4

the effect of hypervolemia and hypervolemia on the rate at which venous collapse happens

Question 5

How does hypervolemia affect central venous pressure and venous collapse?

Answer 5

Central venous pressure is higher than normal and venous collapse occurs at a higher than normal level of cardiac output

Question 6

How does hypovolemia affect central venous pressure and venous colapse?

Answer 6

Central venous pressure is lower than normal and venous collapse occurs at a lower than normal level of cardiac output

Question 7

How does vasodilation affect central venous pressure and venous collapse?

Answer 7

Central venous pressure is normal but venous collapse occurs at a higher than normal level of cardiac output

Question 8

How does vasoconstriction affect central venous pressure and venous collapse?

Answer 8

Central venous pressure is normal but venous collapse occurs at a lower than normal level of cardiac output

Question 9

What are the main pathophysiologic causes of heart failure?

Answer 9

myocardial failure, volume overload, pressure overload, decreased ventricular compliance, cardiac arrhythmias

Question 10

Why does myocardial failure cause heart failure?

Answer 10

poor contractility; dilated cardiomyopathy

Question 11

Why does volume overload cause heart failure?

Answer 11

chronic, excessive preload; AV valve regurgitation

Question 12

Why does pressure overload cause heart failure?

Answer 12

chronic excessive afterload; A or P valve stenosis - heartworm disease

Question 13

Why does decreased ventricular compliance cause heart failure?

Answer 13

impaired filling; cardiac tamponade, hypertrophic cardiomyopathy

Question 14

Why do cardiac arrhythmias lead to heart failure?

Answer 14

sustained tachy- or brady arrythmias