Cardiac Muscle

Question 1

1 unit, surrounded by sarcolemma, 1 nucleus

Answer 1

Cardiac muscle fiber

Question 2

each muscle fiber is joined with another cell by

Answer 2

Intercalated discs

Question 3

cardiac muscles behave _____, with gap junction

Answer 3

syncytium

Question 4

T-system of cardiac muscle is located in ______ instead of ______ junction

Answer 4

Z-lines, A-I junction

Question 5

Cardiac muscle contraction starts with ______

Answer 5

Ca2+

Question 6

To release the stored Ca++, _____ enters cardiac muscle to trigger _________ release

Answer 6

Ca, intracellular calcium

Question 7

In excitation-coupling, membrane is depolarized by _____ which opens _________ channels in T-tubules. It then enter cytosol, binding on open _________ receptor

Answer 7

Na+; L-type Ca2+; Ryanodine Ca2+ receptor (RyR)

Question 8

_______ pumps back SR Ca2+ to SR to relaxation

Answer 8

Sarcoplasmic Reticulum Ca2+ ATPase (SERCA)

Question 9

Membrane is ____ and ____ exits to end AP

Answer 9

Repolarized, K+

Question 10

________ inhibits SERCA activity which is inhibited by its ______. Increase in _____ activates adrenergic receptor which turns on / activate _______ enzyme that cause phosphorylation

Answer 10

Phospholamban, phosphorylation, adrenal medullary epinephrine; adenylyl cyclase