Quiz 3 - Cardiac Physiology

Question 1

Cardiac output equals

Answer 1

stroke volume x heart rate

Question 2

QRS complex on an EKG signifies

Answer 2

ventricular depolarization

Question 3

Pace maker of heart is

Answer 3

SA Node

Question 4

Term for volume in ventricle at end of diastole:

Answer 4

EDV (end diastolic volume)

Question 5

Ventricular repolarization on an EKG?

Answer 5

T Wave

Question 6

In isovolumetric relaxation —

Answer 6

ventricles are relaxing… Brief period when volume in ventricles does not change – as ventricles relax, pressure drops and AV valves open

Question 7

T/F: Heart lies within the mediastinum anterior to sternum.

Answer 7

False. Heart lies posterior to sternum within mediastinum.

Question 8

Period of time where cardiac muscles cannot go through second depolarization, can not get excited:

Answer 8

Refractory period

Question 9

Equation for stroke volume:

Answer 9

Stroke volume = the volume ejected per beat from each ventricle, about 70 ml...  
Stroke Volume (SV) = End Diastole Volume (EDV) - End Systole Volume (ESV)

Question 10

T/F: First stage of ventricular filling is rapid filling

Answer 10

True

Question 11

Describes types of muscle contraction:

Answer 11

Concentric isotonic contraction: muscle shortens and pulls on another structure (lifting glass of water to your mouth)
Eccentric isotonic contraction: muscle length increases during contraction (returning glass of water from mouth to rest on table (negative physical activity)
Isometric contractions: myosin cross bridges generate tension but muscle doesn’t shorten because load equals muscle tension (maintaining posture)