Asked by Onaiz Fahim on Jun 17, 2024
Verified
Arrange these structures as they participate in excitation-contraction.
A) T tubules, sarcolemma, Ca2+, sarcoplasmic reticulum
B) Ca2+, T tubules, sarcolemma, sarcoplasmic reticulum
C) Sarcolemma, T tubules, sarcoplasmic reticulum, Ca2+
D) Sarcoplasmic reticulum, Ca2+, T tubules, sarcolemma
E) Sarcolemma, sarcoplasmic reticulum, Ca2+, T tubules
Excitation-Contraction
A biological mechanism that describes the process of muscle fiber contraction triggered by electrical impulses.
T Tubules
Tube-like structures in muscle cells that play a role in transmitting electrical impulses from the cell surface to the interior, triggering muscle contraction.
Sarcolemma
The fine transparent tubular sheath which envelops the fibers of skeletal muscles.
- Elucidate the sequence of events in excitation-contraction coupling within skeletal muscle fibers.
Verified Answer
TA
Tyler AlexanderJun 20, 2024
Final Answer :
C
Explanation :
The correct sequence for the structures participating in excitation-contraction coupling in muscle cells starts with the sarcolemma (muscle cell membrane), which depolarizes and transmits the action potential to the T tubules. This, in turn, signals the sarcoplasmic reticulum to release calcium ions (Ca2+), initiating the contraction process.
Learning Objectives
- Elucidate the sequence of events in excitation-contraction coupling within skeletal muscle fibers.