Skeletal Muscle Anatomy and the Neuromuscular Junction

Front

What is the sarcoplasmic reticulum?

Back

A specialized smooth endoplasmic reticulum that surrounds each myofibril, stores calcium, and releases it on demand.

Front

What is released from the sarcoplasmic reticulum during muscle contraction?

Back

Calcium ions.

Front

What must occur first before a muscle can contract?

Back

An action potential must be sent through neurons in the nervous system.

Front

In response to action potentials arriving from the transverse tubules, where are calcium ions released from?

Back

Sarcoplasmic reticulum.

Front

What role does calcium play in muscle contraction?

Back

Calcium triggers the binding of myosin to actin.

Front

What is the function of the neuromuscular junction?

Back

It is the synapse between a motor neuron and a muscle fiber, where the neuron communicates with the muscle to initiate contraction.

Front

What is the role of ATP in muscle contraction?

Back

ATP provides the energy required for muscle contraction and relaxation.

Front

What is the function of thick filaments in muscle fibers?

Back

Thick filaments are primarily composed of myosin and are responsible for generating force during muscle contraction.

Front

What is the function of thin filaments in muscle fibers?

Back

Thin filaments are primarily composed of actin and are involved in the contraction process by interacting with myosin.

Front

What is the role of the sarcolemma in muscle fibers?

Back

The sarcolemma is the cell membrane of a muscle fiber that conducts action potentials and helps maintain the ionic environment.