Cardiac Concepts: Part One

Question 1

Explain Cardiac Depolarization

Answer 1

This is when the cell that is slightly negatively charged changes by allowing Sodium to rush in and potassium to rushing out giving the cell a positive charge. Then the cell allows calcium to enter the cell as well which charges it more positively. This is what allows the heart to contract. When one cell does this (depolarization) all the other cells in that syncytium contact. The atria does this from superior to inferior while the ventricles do this from inferior to superior.

Question 2

Excitablility

Answer 2

Cells can respond to an electrical stimulus

Question 3

Conductivity

Answer 3

Cells can propagate the electrical impulse from cell to cell

Question 4

Automaticity

Answer 4

Each conductive cell can depolarize without any outside impulse.

Question 5

Contractility

Answer 5

Cells have the ability to contract