Cardiac Cycle and Cardiac Output

Question 1

What are the effects of angiotensin II on the heart?

Answer 1

Question 2

What effect does thyroid hormones have on the heart?

Answer 2

Question 3

What effect does insulin and glucagon have on the heart?

Answer 3

Question 4

What are three ways to measure cardiac output?

Answer 4

Echocardiography
Measures SV through LV outflow tract
CO=HRxSV

Swan Ganz Pumlonary Wedge Pressure
Catheter tip floated into pulmonary artery, balloon inflated and wedged in branch of pulmonary artery which occludes vessel
Approximately equal to the left atrial pressure in which you can approximate CO

Fick Principle
Q=VO2/(Ca02-Cv02)
=250/5=50dL/min
=5L/min

Question 5

What effect does hypokalaemia have on cardiac contraction? Hyperkalaemia?

Answer 5

Question 6

What effect does hypcalcaemia have on cardiac contractility? Hypercalcaemia?

Answer 6

Question 7

What is the Frank-Starling Mechanism?

Answer 7

Question 8

What does an increased preload do to stoke volume?

Answer 8

Increased preload increases stroke volume and force of contraction

Question 9

What is afterload? What effect does increasing afterload have on stroke volume?

Answer 9

Force that the contracting myocytes must overcome
Large increases in arterial pressure or aortic pressure, aortic stenosis
Impairs stroke volume and CO

Question 10

What is the distribution of blood in circulation?

Answer 10

Question 11

Which blood vessels contain smooth muscle?

Answer 11

Arteries, arterioles and veins

Question 12

How does the structure of different blood vessels lead to thier function?

Answer 12

Question 13

How to valves in veins help induce one way blood flow?

Answer 13

Valves prevent backflow
Skeletal muscle contraction helps force blood toward the heart (like a pump)

Question 14

Blood pressure is the force exerted by the blood against a vessel wall, what are the systemic and pulmonary pressures of the following:

Left atrium, left ventricle, aorta
Right atrium, right ventricle, pulmonary arteries
Capillaries

Answer 14

Question 15

What is a good estimation of MAP?

Answer 15

MAP = Diastolic pressure + 1/3 (Pulse pressure)

MAP = 2/3 Diastolic + 1/3 Systolic

Question 16

Pulse pressure is determined by? (2)

Answer 16

Question 17

What is arteriosclerosis? What is the most common cause of it?

Answer 17

Question 18

What are common causes of hypertension?

Answer 18

Question 19

What can chronic hypertension cause?

Answer 19