A&PII Lab 5: The Cardiovascular System - Heart Physiology

Question 1

Systole

Answer 1

contraction phase

Question 2

Diastole

Answer 2

relaxation phase

Question 3

Auscultation

Answer 3

most common method of examining basic heart function; physical examination consisting of listening to internal sounds using a stethoscope (amplifies sound)

Question 4

Lubb

Answer 4

1st audible sound through a stethoscope; S1; occurs at ventricular systole; produced by blood turbulence resulting from the closure of the 2 AV valves

Question 5

Dupp (dubb)

Answer 5

2nd sound; briefer and slightly sharper than 1st; occurs at ventricular diastole, when the ventricles relax and the 2 semilunar valves close

Question 6

Heart rate

Answer 6

number of heartbeats (lubb-dupp) in 1 minute

Question 7

Murmur

Answer 7

most frequent condition that can be diagnosed by auscultation; swishing sound usually caused by a backflow of blood, or regurgitation; most common cause of this is a valvular defect

Question 8

Stenosis

Answer 8

valvular defect that can be heard by auscultation; defects in 1 or more valves result in a narrowing of the passage; usually heard as a high-pitched sound (“screeching”) as blood is pushed through narrow passages

Question 9

Pulse pressure

Answer 9

difference between diastolic and systolic pressure

Question 10

Pulse rate

Answer 10

pulsations produced by the left ventricle, counted in a 1-minute interval of time

Question 11

Autorhythmic cells

Answer 11

specialized heart cells which contract and relax on their own signals

Question 12

Conduction system

Answer 12

autorhythmic cells form the core of this system of the heart

Question 13

Sinoatrial (SA) node

Answer 13

the cluster of cells that initiates each cardiac cycle

Question 14

Atrioventricular (AV) node

Answer 14

a 2nd cluster of autorhythmic cells; can be found in the lower interartrial septum near the opening to the coronary sinus

Question 15

AV bundle (bundle of His)

Answer 15

cluster of fibers located in the lower part of the interatrial septum just above the interventricular septum; forms the electrical connection between the atria and ventricles by sending action potentials to the bundle branches

Question 16

Right and left bundle branches

Answer 16

branches extending down the interventricular septum

Question 17

Purkinje (conduction) fibers

Answer 17

final distribution legs of the heart conduction system; located in the apex of the myocardium and lateral walls of both ventricles; they carry action potentials to the ventricular myocardium to cause contraction

Question 18

Electrocardiograph

Answer 18

instrument that detects and records the electrical currents generated by the conduction system of the heart

Question 19

Electrocardiogram (ECG)

Answer 19

record of the electrical changes that occur during cardiac cycles

Question 20

P wave

Answer 20

1st wave of an ECG; relatively small deflection wave indicating depolarization of the atria immediately before atrial contraction

Question 21

QRS complex

Answer 21

2nd wave of an ECG; very steep deflection wave resulting from depolarization of the ventricles, which precede ventricular contraction

Question 22

T wave

Answer 22

less height, broader base; caused by currents produced during ventricular repolarization

Question 23

Normal sinus rhythm (NSR)

Answer 23

heart rate ranging from 60-100 beats per minute

Question 24

Tachycardia

Answer 24

heart rate exceeding 100 beats per minute

Question 25

Bradycardia

Answer 25

heart rate below 60 beats per minute

Question 26

Fibrillation

Answer 26

prolonged tachycardia may progress into this condition of rapid, inefficient contractions that render the heart useless as a pump

Question 27

Heart rate calculation (ECG)

Answer 27

distance measured between the start of one P wave to the start of the next P wave; multiply the # of squares counted by 0.04 seconds; product = length of 1 cardiac cycle