Lecture 8: Heart as a pump

Question 1

What do AV valves control?

Answer 1

control flow between the atria and ventricles

Question 2

What do Aortic and pulmonary valves control?

Answer 2

flow from the ventricles out to the circulatory vessels

Question 3

How do we increase force of cardiac contraction?

Answer 3

by increasing cytosolic levels of Ca2+ we increase the numbers of cross bridges formed so greater contraction.
Relaxation = less Ca2+

Question 4

What are the five stages of the cardiac cycle?

Answer 4

1. Atrial systole
2. Isometric ventricular contraction
3. Ventricular ejection
4. Isometric ventricular relaxation
5. Passive filling

Question 5

What is typically longer, Diastole or Systole?

Answer 5

Diastole is typically longer than systole

Question 6

What is pulse pressure?

Answer 6

• Pulse pressure is the difference between the highest and lowest points

Question 7

What is Hypertension in terms of blood pressure and Hypotension?

Answer 7

Hypertension is high blood
pressure, while hypotension
is low blood pressure

Question 8

What is mean blood pressure?

Answer 8

Mean pressure is the average
across the full cycle, remember that it is brought down by longer time spent in diastole.

Question 9

What are the “lubb” and “dupp” sounds created by?

Answer 9

“Lubb” - AV valves closing
“Dupp” - Semilunar valves closing