structure of work cardiomyocytes and relation to contraction

Question 1

describe the sequence of events for contraction to happen in a work cardiomyocyte

Answer 1

1. depolarizing event by gap junctions (Na+ goes into cell)
2. triggers the opening of the VG Na+ channels (causes the action potential)
3. triggers the L-type calcium channel to open
4. Calcium induced calcium release (calcium can either go to RYR and calcium comes out the sarcoplasmic reticulum or calcium can go directly to the myofilament) either way activation of the myofilaments happens by binding calcium to trop c
5. contraction or power stroke happens
6. remove the calcium from the sarcoplasm by SERKA, NCX and Ca+ pumps
7. repolarization and diastole

Question 2

connexons

Answer 2

protein structure that actually forms the gap junction

Question 3

troponin I binds

Answer 3

actin

Question 4

troponin t binds

Answer 4

tropomyosin

Question 5

troponin c binds

Answer 5

calcium