Heart

Question 1

The tubules store larger amounts of Ca++ in cardiac muscle than skeletal muscle

Answer 1

True

Question 2

Wha is the T tuble mechanism

Answer 2

Direct diffusion of Ca++

Question 3

Strength of contraction in heart muscle is dependent on what

Answer 3

Extra cellular Ca++

Question 4

Ventricular Action Potential resting potential.

Why is there a plateau

Answer 4

-90mV

Second phase of sodium/calcium channels (slower)

Question 5

pacemaker

Answer 5

SA mode

Question 6

The SA Node has ______ contractile muscle fibers

Answer 6

Almost no

Question 7

Less negative resting membrane potential than other cardiac muscle cells

Answer 7

SA node (leaky to Na+ and Ca++ ions)

Question 8

-40 mV threshold

Answer 8

SA node

Question 9

EDV

End-diastolic volume

Answer 9

Amount of blood in ventricle at end of diastole

Question 10

ESV

End Systolic volume

Answer 10

Volume of blood left in ventricle after fully contracts

Question 11

Ejection fraction

Answer 11

Fraction of blood that is ejected out

55-70%

Question 12

Atrial function ____ except during vigorous exercise

Answer 12

Unnecessary

Question 13

Atrial contraction usually causes an additional 20% ventricle filling

Answer 13

Primer pump

Question 14

Heart pumps _____ L of blood/min

Answer 14

4-6

*might have to pump 4-7x with heavy exercise

Question 15

Why is left ventricular muscle thicker

Answer 15

Has to pump blood thru left atrium to body