Cardiovascular Physiology

Question 1

Systolic Pressure

Answer 1

Peak arterial pressure reached during the cardiac cycle

Question 2

Diastolic Pressure

Answer 2

Arterial pressure is at its lowest (right before the ventricles push blood into the arteries)

Question 3

Dicrotic Notch

Answer 3

Closure of the aortic valve

Question 4

Starlings law of the heart

Answer 4

The strength of a cardiac contraction is determined by the strength of the ventricular muscle

Question 5

At what pressure does blood enter the atrial chambers of the heart?

Answer 5

Low pressure

Question 6

At what pressure does blood lead the ventricles of the heart?

Answer 6

high pressure

Question 7

What are the Atrioventricular valves (AV)?

Answer 7

The Tricuspid and Mitral valves

Question 8

Where are the AV valves located?

Answer 8

Between the atrium and ventricle on each side of the heart

Question 9

What is the purpose of the AV valves?

Answer 9

To prevent the backflow of blood from the ventricle to the atrium

Question 10

What is the purpose of the semilunar valves?

Answer 10

To prevent the back flow of blood from the pulmonary valve (right side) or aorta (left side) to the ventricles

Question 11

What sound does the closing of the AV valves make?

Answer 11

“lub”

Question 12

What sound does the closure of the semilunar valves make?

Answer 12

“dub”

Question 13

Sinoatrial (SA) node

Answer 13

• Pacemaker of the heart
• Produce action potentials that spread through the muscle fiber of the atria casein the atria to contract

Question 14

What happens when the atria contracts?

Answer 14

• Ventricles (relaxed) fill with blood
• AV valves are open

Question 15

Atrioventricular (AV) node

Answer 15

• Electrical connection between the atria and ventricles
• Action potentials (from SA node) spread slowly through AV node allowing the atrial contraction to contribute to ventricular filling

Question 16

AV bundle and Purkinje fibers

Answer 16

Action potentials spread rapidly through these cells in order to excite the ventricles in preparation for contraction

Question 17

P-Wave

Answer 17

Atrial depolarization

Question 18

QRS Complex

Answer 18

Ventricular depolarization and atrial repolarization

Question 19

T-Wave

Answer 19

Ventricular repolarization

Question 20

What is the sequence of events in the heart during a cardiac cycle?

Answer 20

1. Early ventricular diastole
2. Late ventricular diastole
3. Atrial systole
4. Early ventricular systole
5. Late ventricular systole

Question 21

Early ventricular diastole

Answer 21

• Deoxygenated blood returns to the heart from the body and enters the right atrium
• Oxygenated blood returns to the heart from the lungs and enters the left atrium
• AV valves = open
• Semilunar valves = closed
• Ventricles = relaxed
• Atria pressure > ventricular pressure

Question 22

Late ventricular diastole

Answer 22

• Blood flows into the ventricles
• AV valves = open
• Ventricles = relaxed
• Atria pressure > ventricular pressure

Question 23

Atrial systole

Answer 23

• Atria contracts
• Ventricles = relaxed
• Ventricular filling is complete
• Atria pressure > ventricular pressure

Question 24

Early ventricular systole

Answer 24

• Ventricles begin to contract
• Ventricular pressure rises to exceed pressure in the atria
• AV valves close
• Pressure in ventricles has not yet exceeded pressure in the pulmonary artery / aorta (Isovolumetric contraction)

Question 25

Late ventricular systole

Answer 25

• Pressure in ventricles exceeds pressure in the aorta and pulmonary arteries
• Semilunar valves open and blood is ejected into the aortic and pulmonary arteries

Question 26

Wiggers Diagram

Answer 26

CERIDS
1. Isovolumic contraction
2. Ejection
3. Isovolumic relaxation
4. Rapid inflow
5. Diastases
6. Atrial systole