U5 Practice Test Muscular System 24-25

Front

What is the primary function of the biceps muscle?

Back

The biceps muscle primarily functions to flex the elbow and rotate the forearm.

Front

What is a neurotransmitter?

Back

A neurotransmitter is a chemical messenger that transmits signals across a synapse from one neuron to another or to a muscle cell, with acetylcholine being a key example.

Front

What role does the motor neuron play in muscle contraction?

Back

The motor neuron sends electrical signals to muscle cells, initiating muscle contraction.

Front

What are the two main types of filaments in muscle contraction?

Back

The two main types of filaments are myosin (thick filaments) and actin (thin filaments).

Front

What is the synaptic cleft?

Back

The synaptic cleft is the small gap between a neuron and a muscle cell where neurotransmitters are released.

Front

What is the role of calcium ions (Ca²⁺) in muscle contraction?

Back

Calcium ions (Ca²⁺) are released from the sarcoplasmic reticulum and bind to troponin, allowing myosin to bind to actin and initiate contraction.

Front

What is the sarcolemma?

Back

The sarcolemma is the cell membrane of a muscle cell that surrounds the muscle fiber.

Front

What is the difference between skeletal muscle and smooth muscle?

Back

Skeletal muscle is striated and under voluntary control, while smooth muscle is non-striated and under involuntary control.

Front

What is the sliding filament theory?

Back

The sliding filament theory explains how muscles contract by the sliding of actin filaments over myosin filaments, shortening the muscle fiber.

Front

What is the function of the deltoid muscle?

Back

The deltoid muscle is responsible for shoulder abduction, flexion, and extension.