Unit 1

Question 0

What major element determines cardiac contractivity?

Answer 0

Calcium

Question 1

Dimensions of an adult heart

Answer 1

• 5 in long
• 3 1/2 inches wide
• 2 1/2 inches thick
• 250-350 g= 11 oz= about the size of the fist

Question 2

Endocardium

Answer 2

Smooth layer of cells that lines the inside of the heart; allows for smooth flow of blood

Question 3

Myocardium

Answer 3

Muscular middle layer; thickest layer of the heart

Question 4

Pericardium

Answer 4

Double layered membrane that covers outside of the heart

Question 5

Septum

Answer 5

Muscular wall that separates the left and right sides

Question 6

Right atrium

Answer 6

Receives deoxygenated blood from the body

Question 7

Right ventricle

Answer 7

Receives blood from from right atrium and pumps blood into pulmonary artery

Question 8

Left atrium

Answer 8

Receives oxygenated blood from the lungs

Question 9

Left ventricle

Answer 9

Receives blood from left atrium and transports blood back to body through aorta

Question 10

Tricuspid valve

Answer 10

Located between right atrium and ventricle; prevents blood from flowing back into right atrium

Question 11

Possible causes of myocardial infarction

Answer 11

• smoking
• heavy meals
• CHF
• exercise
• anemia
• inadequate oxygen supply
• coronary artery narrowing (blockage)
• hypoxemia

Question 12

Items needed to do an EKG

Answer 12

1. Machine
2. Electrodes
3. Leads
4. EKG paper
5. patient gown
6. alcohol wipes
7. Shaving supplies
8. patient’s chart

Question 13

Sympathetic nervous system

Answer 13

Mobilizes fight or flight response

effects heart rate

Increases automaticity (ability to do things without occupying the mind with the low-level details required, allowing it to become an automatic response pattern or habit)

Question 14

Parasympathetic

Answer 14

Has most influence on heart

sinus arrhythmia originates

inhibits automaticity

Question 15

Location of the heart

Answer 15

Sits behind sternum and just above the diaphragm; lies mediastinum (space between the lungs) in the middle of the chest

^2/₃ of the heart lies left of midline of sternum

Question 16

Precordium

Answer 16

Portion of the body over the heart and lower chest

Question 17

Coronary Circulation

Answer 17

The system of circulation in which the heart gets its blood supply

Question 18

Right coronary artery has a direct effect on what?

Answer 18

Heart rate; patients with right coronary artery occlusion (closure) and resulting inferior wall myocardial infarction may have bradycardia or various degree of heart block

Question 19

Preload

Answer 19

Amount of muscle stretch at the beginning of a contraction

Question 20

Afterload

Answer 20

The pressure against which it has to pump

Question 21

Contractility

Answer 21

The force of the contraction

Question 22

3 events that occur during cardiac cycle

Answer 22

Ventricular systole (contraction)

Ventricular diastole (relaxation)

Atrial systole (contraction)

Question 23

SA node (Sino atrial node)

Answer 23

Acts as hearts natural pacemaker; located on right upper corner near anastamosis of superior and inferior vena cava

Question 24

Frank Starling's law

Answer 24

## Footnote The greater the stretch of cardiac muscles, the stronger the contraction

Question 25

Artifact

Answer 25

Disturbances in the EKG which can be caused by incorrect placement of lead or movements of patient

Question 26

Systole

Answer 26

Contracting phase in which blood is expelled from the heart

Question 27

Diastole

Answer 27

Relaxation phase is which the heart fills with blood