Lab 6

Question 1

what occurs in the plateau phase

Answer 1

Ca + + moves in slowly and sustained

Question 2

how many chambers does a frog heart have

Answer 2

3

Question 3

how many chambers does a human heart have

Answer 3

4

Question 4

Frank Stearling Law of The Heart

Answer 4

Stroke volume of the heart increases in response to an
increase in the volume of blood filing the heart

Question 5

increased blood volume =

Answer 5

increased stretch of the myocardium

Question 6

Role of Norepinephrine

Answer 6

NE binds beta-adrenergic receptors on cells of SA node

Question 7

Role of Acetylcholine (Ach):

Answer 7

ACh binds to muscarinic receptors on cells of SA node
causing a membrane hyperpolarization

Question 8

what ion current, regulate spontaneous depolarization
(generating pacemaker potentials at threshold)

Answer 8

Potassium

Question 9

cardiac output =

Answer 9

Heart rate * Stroke Volume

Question 10

what causes the P wave

Answer 10

atrial depolarization caused by SA node

Question 11

after atrial depolarization where is the impulse delayed

Answer 11

AV node

Question 12

where does ventricular depolarizatoin begin? what does this cause?

Answer 12

Apex
QRS complex and atrial repolarization

Question 13

what causes the T wave

Answer 13

ventricular repolarization at apex

Question 14

where are pacemaker cells located in

Answer 14

sinoatrial node (SA)

Question 15

function of SA node

Answer 15

produce pacemaker potentials which depolarize membrane and produce AP

Question 16

where all the gap junctions located

Answer 16

intercalated disks between adjacent myocardial cells

Question 17

function of AV nodes

Answer 17

provide an electrical pathways between the atria and ventricles

Question 18

after depolarization passes through AV node where does it go to

Answer 18

bundle of HIs to Purkinje Fibers

Question 19

function of purkinje fibers

Answer 19

make gap junctional contacats with most myocardial cells in ventricles

Question 20

electrocardiogram function

Answer 20

recording of cardiac electrical activity

Question 21

components of the ECG are

Answer 21

P wave
QRS complex
T wave

Question 22

sphygmomanometer apparatus function

Answer 22

use ECG recordings and blood pressure to investigate heart rate

Question 23

T/F heart rate is profoundly influenced by the ANS

Answer 23

T

Question 24

define cardiac output

Answer 24

produce of Heart Rate X Stroke Volume

Question 25

name the piezo-electric device that works as an accelerometer

Answer 25

pulse transducer

Question 26

function of pulse transducer

Answer 26

converts movements of active surface of transduce into an electrical signal

Question 27

blood flow is directly dependent on

Answer 27

blood pressure

Question 28

what is a sphygmomanometer

Answer 28

inflatable blood pressure cuff conneceted to a manometer

Question 29

purpose of sphygmomanometer

Answer 29

occlude blood flow in the brachial artery

Question 30

define systolic pressure

Answer 30

pressure at which pulse is again detectable

max bp

Question 31

define diastolic pressure

Answer 31

pressure at which normal height is regained

Question 32

what must you swab the skin with

Answer 32

cotton wool with 70% alcohol solution at the area where you will place each electrode

Question 33

where is the “earth” connected to

Answer 33

patients akle

Question 34

how is bp usually recorded?

Answer 34

systolic/diastolic

Question 35

define respiratory cardiac arrhythmia

Answer 35

a variation in heart rate that occur with each cycling of breathing

Question 36

the condition respiratory cardiac arrhythmia is more pronounce in

Answer 36

children

Question 37

at inspiration what pressure decereases

Answer 37

intrathoracic

Question 38

Describe Bainbridge Reflex

Answer 38

increased venous filling activates stretch receptors in vena cava and right atrium

info sent to medulla

alters heart rate

Question 39

Describe Baroreceptor Reflex

Answer 39

changes in arterial pressure which stimulate baroreceptors in aorta and carotid bodies

info sent to medulla

alters heart rate

Question 40

at expiration what pressure increases

Answer 40

intrathoracic