exam

Question 1

the pacemaker potential occurs during

Answer 1

diastole

Question 2

diastole

Answer 2

relaxation/resting peroid of heart

Question 3

diastole

Answer 3

relaxation/resting period of heart

Question 4

systole

Answer 4

contraction of the heart

Question 5

1. SA node (pacemaker)
2. AV node
3. bundle of His
4. R & L bundle branches
5. Purkinjie fibers

Answer 5

conduction system of the heart

Question 6

• pacemaker of the heart
  -sends signals to AV
  -located in R atrium near the superior vena cava
  -parasympathetic & sympathetic

Answer 6

SA node

Question 7

pacemaker potential

Answer 7

slow, spontaneous depolarization

Question 8

SA nodes do not have

Answer 8

a maintained RMP

Question 9

• Resting membrane Potential = -85mV
  -long phase (slow) (200-300ms)
  -plateau phase
• no summation or tetanus

Answer 9

Myocardial action potential

Question 10

Source of calcium in muscle

Answer 10

• sarcoplasmic reticulum
• extracellular fluid

Question 11

sarcoplasmic reticulum

Answer 11

stores calcium in muscle cells

Question 12

• fast
• all Ca2+ comes from the sarcoplasmic reticulum
  -somatic (voluntary)
• striated, nuclei pushed to edges

Answer 12

skeletal

Question 13

-Ca2+ comes from the sarcoplasmic reticulum and out of the cell
-autonomic (involuntary)
-striated, nuclei scattered, intercalated disks, branching

Answer 13

cardiac muscle

Question 14

-almost all Ca2+ comes extracellular
-autonomic (involuntary) (slowest)

Answer 14

smooth muscle

Question 15

Main differences between skeletal and cardiac muscle

Answer 15

cardiac branches and has intercalated disks (gap junction)

Question 16

HCN channels

Answer 16

open in response to hyperpolarization

Question 17

HCN channels (broken down)

Answer 17

H: hyperpolarization
CN: cyclic nucleotide (AMP)

Question 18

threshold in heart

Answer 18

-40mV

Question 19

once the heart reached the threshold…..

Answer 19

opens voltage regulated Ca2+ channels

Question 20

calcium induced

Answer 20

calcium released

Question 21

calcium from sarcoplasmic reticulum

Answer 21

causes muscle contractions

Question 22

repolarization occurs (in heart)

Answer 22

with the opening of voltage-gated potassium channels

Question 23

plateau phase

Answer 23

caused by slow calcium channels
potassium gives plateau
correlated to S-T segment

Question 24

summation or tetanus is prevented by?

Answer 24

long refractory period

Question 25

A recording of the electrical activity of the heart

Answer 25

ECG/EKG (electrocardiogram)

Question 26

ventricular depolarization and atrial repolarization

Answer 26

QRS complex

Question 27

T wave

Answer 27

ventricular repolarization

Question 28

bipolar leads

Answer 28

Lead I, II, III (R&L wrist, L ankle)

Question 29

thick middle muscle layer of the heart

Answer 29

Myocardium

Question 30

membrane surrounding the heart

Answer 30

Pericardial sac

Question 31

volume of blood in each ventricle at end of ventricular diastole

Answer 31

End diastolic volume (EDV)

Question 32

volume of blood remaining in each ventricle after systole

Answer 32

end-systolic volume (ESV)

Question 33

the volume of blood pumped forward with each ventricular contraction SV=EDV-ESV

Answer 33

stroke volume

Question 34

what is the most important factor in examination of a single cardiac cycle?

Answer 34

Stroke volume

Question 35

- the amount of blood pumped in 1 minute (mL/min) - an indication of blood flow through peripheral tissue (blood) - provides information about ventricular efficiency

Answer 35

cardiac input

Question 36

what does cardiac output provide?

Answer 36

information about ventricular efficiency.

Question 37

cardiac output can be adjusted by

Answer 37

changes in either stroke volume or heart rate

Question 38

says the greater the volume of blood within the ventricle the greater the force of contraction

Answer 38

Frank Sterling Law (of the Heart)

Question 39

systolic pressure

Answer 39

1st of Korotkoff occurs when the cuff pressures120

Question 40

diastolic pressures

Answer 40

last sound of Korotkoff is heard when the pressure 80

Question 41

pressure forcing blood into tissues averaged over the cardiac cycle MAP = diastolic pressure +1/3 pulse pressure

Answer 41

Mean Arterial Pressure (MAP)

Question 42

difference between systolic and diastolic pressure =systolic pressure-diastolic pressure

Answer 42

pulse pressure

Question 43

the primary reflex pathway for homeostatic control of blood pressure

Answer 43

baroreceptor

Question 44

Baroreceptors consist of

Answer 44

1. Sensors: aortic arch and carotid sinus baroreceptor 2. Control center: vasomotor cardiac control centers of medulla oblongata 3. Effectors: parasympathetic and sympathetic axons to heart and blood vessels