CV Physiology

Question 1

Pericardium

Answer 1

Deep two-layered serous pericardium:
Parietal layer :internal surface of fibrous pericardium
Visceral layer (epicardium): external surface myocardium
Separated by fluid-filled pericardial cavity (decreases friction)

Question 2

Vessels entering right atrium

Answer 2

Superior vena cava
Inferior vena cava
Coronary sinus

Question 3

Vessels entering left atrium

Answer 3

Right and left pulmonary veins

Question 4

During what period of the cardiac cycle do the coronary arteries receive perfusion?

Answer 4

Diastole

Question 5

Semilunar Valves

Answer 5

Aortic

Pulmonic

Question 6

AV Valves

Answer 6

Mitral- Left

Tricuspid- Right

Question 7

Autorhythmic Cells Have unstable resting potentials due to

Answer 7

slow slow Na+ channels

At threshold, Ca2+ channels open

Question 8

delays cardiac impulse

Answer 8

Most delay is in A-V node
Delay AV node – 0.09 sec.
Delay AV bundle – 0.04 sec.

Question 9

Heartbeat is modified by…

Answer 9

the ANS

Cardiac centers are located in the medulla oblongata

Question 10

Lubb

Answer 10

first heart sound (S1)
occurs during ventricular systole
A-V valves closing

Question 11

Dupp

Answer 11

second heart sound (S2)
occurs during ventricular diastole
pulmonary and aortic semilunar valves closing

Question 12

Cardiac Output (CO)

Answer 12

Volume of blood pumped by each ventricle in one minute

CO = heart rate (HR) x stroke volume (SV)

Question 13

Preload

Answer 13

degree of stretch of cardiac muscle cells before they contract (Frank-Starling law of the heart)
Increase pre-load increases SV
(affects EDV)

Question 14

Afterload

Answer 14

pressure that must be overcome for ventricles to eject blood

Hypertension increases afterload, resulting in increased ESV and reduced SV