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Cardiovascular > Cardiac Muscle > Flashcards

Flashcards in Cardiac Muscle Deck (15)
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1
Q

Contractile cells of Atria, Ventricle are described as this

A

Fast

2
Q

Pacemaker cells rising phase is kicked off by of the increased permeability of these ions

A

Na2+

3
Q

The rising phase of the fast response action potential is the result of a sudden increase in this.

A

Permeability of Na+

4
Q

Resting phase voltage is largely due to this current.

A

I - KI - inward rectifier

5
Q

Protein mechanical attachments in desmosomes

A

adherens

6
Q

These junctions allow electrical current to flow from cell to cell

A

gap junctions

channnels formed by connexin

7
Q

P wave signifies this

A

Atrial depolarization

8
Q

QRS complex is site of these things

A

Ventricular depolarization and masked atrial repolarization

9
Q

Ventricular repolarization on ECG

A

T wave

10
Q

Total duration of ventricular systole signified by this

A

QT interval

11
Q

Conduction time through atria and AV node on ECG

A

PR interval

12
Q

Describe the parasympathetic effects on membrane potential

A

Release of Ach causes increased permeability of K+, slowed HR, neg. chronotropic effect.

13
Q

What is the approximate length of refractory period for cardiac contractile cells?

A

250 ms

14
Q

What are the keys of sympathetic control on the heart?

A

Release of NE increases HR and has a positive chronotropic effect

15
Q

Most Ca2+ stores in the body are found here

A

Sarcoplasmic reticulum