Lectrue1C

Question 1

What two things propagate the action potential in a cardiac muscle cell?

Answer 1

the sarcolemma and the t-tubules

Question 2

What is happening during the UNIQUE plateau during the myocyte action potential?

Answer 2

Ca2+ channels are opening and Ca2+ rushes in from the ECM

Question 3

What does the ECM Ca2+ rush in from the ECM trigger within the cell?

Answer 3

Ca2+ release from the sarcoplasmic reticulum! even more Ca2+!!

Question 4

What determines the magnitude of power by the myofibril?

Answer 4

Amount of Ca2+ available!

Question 5

What about the sarcoplasmic reticulum is different in cardiac muscle from skeletal muscle?

Answer 5

Its less dense (c/o the ECM Ca2+ that rushes in)

Question 6

What about the number of mitochondria is different in cardiac muscle from skeletal muscle?

Answer 6

Cardiac has MUCH more!

Question 7

What are the two components to intercalated discs? Functions?

Answer 7

1. Desmosomes (prevent separation) 2.Gap Junctions (free ion depolarizing current)

Question 8

What is the term for myocardium behaving as a single coordinated unit?

Answer 8

Functional SynCyTium

Question 9

What are the three proteins of the cardiac Troponin?

Answer 9

T.I.C T-Tropomyocin binding I-Inhibitory C-Calcium binding

Question 10

What is the difference between Angina and M.I.?

Answer 10

Angina-cells live….M.I.-cells die

Question 11

How can you tell the difference between angina and M.I.?

Answer 11

Angina goes away with NitroGlycerin treatment

Question 12

What are the markers for a M.I.?

Answer 12

Troponin I