EKG: Cardiac Cycle Review

Question 1

Name the parts of the heart

Answer 1

Question 2

What is the purpose of the cardiac cycle? (3)

Answer 2

1. Move oxygenated blood from lungs to tissues.
2. Move deoxygenated blood from the tissues to lungs
3. Preform above functions in efficient, synchronous manner

Question 3

Diastole is when the heart muscle is ___ and all chambers fill with ___.
Systole is when the heart muscle ____ wave begins at the ___ and then thru the ventricles moves ___ from heart chambers into great ____.

Answer 3

1. Relaxed
2. Blood
3. Contracts/contraction
4. Atria
5. Blood
6. Vessels

Question 4

Explain blood flow thru the heart (3)

Answer 4

1. Veins collect deoxygenated blood from the tissues
2. The vena cava empty into right atrium
3. Blood passes thru right atrioventricular valve (tricuspid valve) into right ventricle of the heart

Question 5

Blood flow thru the heart:
During systole, the ___ ventricle constricts and ___ valve closes.
Blood is ejected from the ___ ventricle thru the ___ valve into the ___ arteries.

Answer 5

1. Right ventricle
2. Tricuspid valve
3. Right ventricle
4. Pulmonary valve
5. Pulmonary artery

Question 6

Cardiac output is…
It depends on two things:

Answer 6

1. Amount of blood that leaves the heart
2. Depends on:
   - Stroke vol: amount of blood ejected w/each cardiac contraction
   - HR: Freq of heart contractions

Question 7

• Word bank:
  Stroke Vol (SV)
  Cardiac Output (CO)
  Heart Rate (HR)
• Formula:
  ___ x ___ = ___

Answer 7

SV x HR = CO

Question 8

T/F: Increased exercise results in increased contractility, increased stroke vol (SV), & decreased HR

Answer 8

False! It increases all of the above: contractility, SV, & HR!!

Question 9

What causes these sounds?
“Lub”
“Dub”

Answer 9

“Lub” - First heart sound: AV valve closing at beg of diastole
“Dub” - Second heart sound: Pulmonic & aortic valves closing at the end of systole

Question 10

SA node is the ___.
AV node is the ___ ___.

Answer 10

1. Pacemaker
2. Signal booster

Question 11

Describe the cardiac cycle (4)

Answer 11

1. Impulse generated at the SA node travels from one muscle cell to the next.
   - Wave pattern
   - Initially causes both atria to contract
   - Blood pushed thru AV valve into ventricles
2. Impulse also travels quickly down the muscle fiber to the AV node.
3. Electrical impulse then spreads thru the muscle cells in the ventricles.
   - Travels down the interventricular septum to the bottom of the ventricles.
4. Purkinje fibers carry impulses from the Bundle of His up into the ventricular myocardium.