Cardiac Structure

Question 1

Volume of blood is dependent on

Answer 1

amount of blood returning to the heart via venous channels as well as the time between heart contractions.

Question 2

functions of heart rely on

Answer 2

orderly conduction of electrical signals and a series of valves that keep the blood flowing through the heart in the correct direction

Question 3

cardiac output

Answer 3

defined as the amount of blood pumped out of the heart times the rate at which the heart is beating

Question 4

stroke volume

Answer 4

the amount of blood pushed into the arteries is considered the stroke volume

Question 5

the number of heart contractions in a minute is what?

Answer 5

heart rate

Question 6

cardiac output per minute

Answer 6

stroke volume x heart rate

Question 7

The cardiac contraction starts with

Answer 7

depolarization of the SA node.

Question 8

SA node composed of

Answer 8

excitable cardiac tissue called P cells

Question 9

P cells internal property

Answer 9

current drift will depolarize far enough to generate an active spike of a fast sodium transient about 80 times per minute

Question 10

P wave

Answer 10

the spreading depolarization is seen as slight positive deflection in the anterior leads of the EKG and is referred to as the P wave

Question 11

After the atria, where does the electrical signal go?

Answer 11

it eventually arrives at the AV node.

Question 12

AV node

Answer 12

located just above the right AV valve anterior to the opening g of the coronary sinus

Question 13

a short delay allows for

Answer 13

full contraction of the atria and completion of the atria filling the ventricles

Question 14

AV node goes to

Answer 14

interventricular septum via AV bundle

Question 15

QRS wave of the EKG

Answer 15

AV conduction and the resulting depolarization of ventricular myocytes

Question 16

QRS corresponds to period of time in the cardiac cycle known as

Answer 16

ventricular systole

Question 17

first heart sound

Answer 17

initiation of systole is heralded by closure of AV valve

Question 18

P-R interval

Answer 18

time between initiation of P Wave and the initial deflection of the QRS

Question 19

Abnormalities of PR interval indicates

Answer 19

varying degrees and severity of heart block

Question 20

Irregular rhythm

Answer 20

determined by the distance between one P wave and the other P wave. is different

Question 21

T wave

Answer 21

corresponds to the time when the ventricles begin to relaxand before the blood returns in volume to fill the heart chamber

Question 22

T wave occurs

Answer 22

during systole, before the beginning of diastole

Question 23

second heart sound

Answer 23

closure of semilunar valves, aortic, and pulmonic valves

Question 24

S-T segment or intervale

Answer 24

time between ventricular myocyte contraction and relaxation

Question 25

If the S-T segment is depressed

Answer 25

excessive strain or cardiac ischemia

Question 26

Elevated S-T segment,

Answer 26

infarction or strain

Question 27

Valves are attached to

Answer 27

fibrous rings that help limit current flow between atria and ventricles