EKG (FINAL)

Question 1

Define tachycardia

Answer 1

• Rapid beating of the heart
• Typically over 100 bpm

Question 2

Define fibrillation

Answer 2

• Rapid, irregular, and unsynchronized contraction of the heart

Question 3

Define bradycardia

Answer 3

• A slow heart rate
• Typically a resting heart rate of under 60 bpm

Question 4

What are electrocardiograms also known as?

Answer 4

EKG

Question 5

What are electrocardiograms?

Answer 5

An electrocardiogram (EKG) is a graphic recording of the electrical changes of the cardiac cycle

Question 6

What do EKGs measure?

Answer 6

• Electrical changes of the cardiac cycle consisting of:
  
  • Voltage
  • Time

Question 7

Describe the cellular structure of cardiac muscle

Answer 7

• Cardiac muscle characterisitics
  
  • Striations
  • Branching
  • Intercalated dics
  • Involuntary

Question 8

What is the purpose of an EKG?

Answer 8

Diagnostic tool

Question 9

What do EKGs not measure?

Answer 9

EKGs do not measure blood flow

Question 10

What do EKGs use for recordings?

Answer 10

EKGs uses pairs of electrodes (leads)

Question 11

What are the purpose of an EKG’s leads/electrodes?

Answer 11

Look at the heart from different angles

Question 12

What are the controlling systems of the cardiac cycle?

Question 13

What type of junctions does the cardiac muslce have?

Answer 13

Gap junctions

Question 14

Define gap junction

Answer 14

• Gap junction
  
  • _​_A junction between adjacent animal cells that allows the passage of materials between the cells

Question 15

How does the cardiac muscle cells exhibit automaticity?

Answer 15

• The cardiac cell’s ability to s_pontaneously generate an electrical impulse_ (depolarize).
• Cells that are dedicated to the purpose of generating an impulse to maintain a heart rate commensurate with the body’s need are called pacemaker cells.

Question 16

How does the myocardium function as a single unit?

Answer 16

• Some cardiac muscle cells are self-excitable or autorhythmic.
  
  • These cells generate an action potential that spreads throughout the myocardium
  • Causing the heart to contract as a single unit

Question 17

What are the two controling systems for cardiac muscle?

Answer 17

1. Autonomic nervous system
2. Intrinsic conduction system (nodal system)

Question 18

Answer 18

Right Atrium

• Recieves deoxygenated blood from the vena cavas

Question 19

Answer 19

Sinoatrial node (SA node)

• “Pacemaker”
• Located in the upper posterior wall of the right atrium

Question 20

What is the function of X?

Answer 20

• Sinoatrial Node (SA Node)
  
  • ​Pacemaker
  • An electrical signal originates within the SA node
    
    • The electrical signal is called the action potential or the cardiac impulse

Question 21

Answer 21

• Atrioventricular node (AV node)
  
  • Located in the floor of the right atrium, near the interatial septum

Question 22

What happens to the cardiac impulse at X?

Answer 22

• Atrioventricular node (AV)
  
  • ​The cardiac impulse slows down as it moves through the AV node into the bundle of His

Question 23

Why is it important for the cardiac impulse to slow down as it moves through the AV node?

Answer 23

• The slow movement delays ventricular activation
  
  • ​Allowing the relaxed ventricle to fill with blood during atrial contraction

Question 24

Answer 24

Purkinje Fibers