Chapter 3

Question 0

Responsible for controlling the rate and rhythm of the heart by coordinating regular depolarization and are found in the electrical conduction system of the heart

Answer 0

Specialized group

Question 1

Responsible for generating the physical contraction of the heart muscle

Answer 1

Myocardial working cells

Question 2

Refers to the point at which a stimulus will produce a cell response

Answer 2

Threshold

Question 3

The ability of cardiac pacemakers cells to generate their own electrical impulses spontaneously without external (or nervous) stimulation

Answer 3

Automatically

Question 4

The ability of cardiac cells to respond to an electrical stimulus, a characteristic shared by all cardiac cells

Answer 4

Excitability

Question 5

The ability of cardiac cells to receive an electrical stimulus and then transmit it to other cardiac cells

Answer 5

Conductivity

Question 6

The ability of cardiac cells to shorten and cause cardiac muscle contraction in response to an electrical stimulus (also referred to as rhythmicity)

Answer 6

Contractility

Question 7

A substance or compound whose molecules dissociate into charged components, or ions, when placed in water, producing positively and negatively charged ions

Answer 7

Electrolyte

Question 8

An ion with a positive charge

Answer 8

Cation

Question 9

An ion with a negative charge

Answer 9

Anion

Question 10

Location and function of automaticity

Answer 10

SA node, AV junction, purkinje network fibers.. Electrical

Question 11

Location and function of excitability

Answer 11

All cardiac cells.. Electrical

Question 12

Location and function of conductivity

Answer 12

All cardiac cells.. Electrical

Question 13

Location and function of contractility

Answer 13

Myocardial muscle cells.. Mechanical

Question 14

(K)

Answer 14

Potassium

Question 15

(Na)

Answer 15

Sodium

Question 16

(Ca)

Answer 16

Calcium

Question 17

(Mg)

Answer 17

Magnesium

Question 18

Three major cations that affect cardiac function

Answer 18

Potassium (K), sodium (Na), and calcium (Ca)

Question 19

Anion examples

Answer 19

Phosphorus (P) and chloride (CI)

Question 20

What plays a major roll in cardiac depolarization and repolarization

Answer 20

Potassium (K)

Question 21

What plays a vital roll in depolarization of the myocardium

Answer 21

Sodium

Question 22

An increase in sodium blood levels is known as

Answer 22

Hypernatremia

Question 23

A sodium deficit is known as

Answer 23

Hyponatremia

Question 24

An increase in potassium blood levels is known as

Answer 24

Hyperkalemia

Question 25

A deficit in potassium blood levels is known as

Answer 25

Hypokalemia

Question 26

State of a cardiac cell in which the inside of the cell membrane is negative compared with the outside of the cell membrane; exists when cardiac cells are in the resting state

Answer 26

Resting membrane potential

Question 27

Change in polarity; a five phase cycle that produces changes in the cell membranes electrical charge; caused by a stimulation of myocardial cells which extends across the myocardium; propagated in an all-or-none fashion

Answer 27

Action potential

Question 28

Cardiac muscle cell groups that are connected together and function collectively as a unit

Answer 28

Syncytium

Question 29

Resting state of a cardiac cell, wherein the inside of the cell is electrically negative relative to the outside of the cell

Answer 29

Polarized state

Question 30

The ability of the cell membrane to change to allow the movement of ions

Answer 30

Permeability

Question 31

Electrical occurrence normally expected to result in myocardial contraction; involves the movement of ions across cardiac cell membranes, resulting in positively polarity inside the cell membrane

Answer 31

Depolarization

Question 32

Process whereby the depolarized cell is polarized and positive charges are again on the outside and negative charges are on the inside of the cell; a return to the resting state

Answer 32

Repolarization

Question 33

What has an important function in myocardial depolarization and myocardial contraction

Answer 33

Calcium

Question 34

An increase in calcium blood levels is known as

Answer 34

Hypercalcemia

Question 35

A calcium deficit is defined as

Answer 35

Hypocalcemia

Question 36

At the cells resting state potassium ion concentration is greater

Answer 36

Inside the cell

Question 37

In the resting state of the cardiac cell sodium ions is greater

Answer 37

Outside the cell

Question 38

The refractory period of atrial muscle lasts approximately

Answer 38

.15 seconds

Question 39

The ventricular muscle contracts at approximately

Answer 39

.25 to .3 seconds thus atrial contractions can be much faster

Question 40

Stage of cell activity in which the cardiac cell cannot spontaneously depolarize

Answer 40

Absolute refractory period

Question 41

The period when repolarization is almost complete, and the cardiac cell can be stimulated to contract prematurely if the stimulus is much stronger than normal

Answer 41

Relative refractory period