Excitation-Contraction Coupling

These flashcards cover essential concepts related to excitation-contraction coupling in muscle physiology.

What initiates muscle contractions during excitation-contraction coupling?

An action potential travels along the sarcolemma and down the T-tubules, triggering voltage-sensitive proteins to release calcium from the sarcoplasmic reticulum.

What is the sarcolemma?

The plasma membrane of the muscle cell.

What role does calcium play in muscle contraction?

Calcium is released from the sarcoplasmic reticulum and binds to troponin, causing tropomyosin to move away and allow contraction.

What is the latent period in muscle contraction?

The time it takes for the impulse to travel from the motor neuron to the point of muscle contraction.

What does the y-axis represent in a muscle contraction graph?

The y-axis represents tension, which is the force created by the muscle.

How long does the latent period last?

It lasts for a short time, measured in milliseconds.

What happens during the contraction phase of muscle contraction?

Myosin heads bind to actin, forming crossbridges and pulling to produce tension.

What is the significance of the flat line during the latent period on a tension graph?

It indicates that the neuromuscular impulse is occurring and physiological processes are happening before contraction begins.