Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
What structure distributes an action potential throughout the inside of a muscle fiber?
A
Sarcoplasmic reticulum
B
Motor end plate
C
T-tubules
D
Myofibrils
Verified step by step guidance
1
Begin by understanding the anatomy of a muscle fiber. Muscle fibers are composed of several structures, including the sarcoplasmic reticulum, motor end plate, T-tubules, and myofibrils.
Recognize the role of T-tubules in muscle contraction. T-tubules, or transverse tubules, are invaginations of the sarcolemma (muscle cell membrane) that penetrate into the cell's interior.
Learn how action potentials are transmitted. When a muscle fiber is stimulated, an action potential travels along the sarcolemma and enters the T-tubules.
Understand the function of T-tubules in distributing action potentials. The T-tubules ensure that the action potential reaches deep into the muscle fiber, allowing for a synchronized contraction.
Connect the role of T-tubules to muscle contraction. The action potential in the T-tubules triggers the release of calcium ions from the sarcoplasmic reticulum, leading to muscle contraction.