Practice 1: Muscle Structure

Front

What is a myofilament?

Back

A myofilament is a filament that constitutes myofibrils, which are the basic units of muscle contraction. The two main types are actin (thin filaments) and myosin (thick filaments).

Front

What is the smallest unit of muscle structure?

Back

The sarcomere is the smallest functional unit of a muscle fiber, responsible for muscle contraction.

Front

What is a group of fascicles called?

Back

A group of fascicles is called a muscle.

Front

What is the smallest structure in muscle fibers?

Back

The myofilament is the smallest structure in muscle fibers.

Front

What is a group of muscle fibers called?

Back

A group of muscle fibers is called a fascicle.

Front

What are the two main types of myofilaments?

Back

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

Front

What is the role of actin in muscle contraction?

Back

Actin provides a track for myosin to pull on during muscle contraction, facilitating the sliding filament mechanism.

Front

What is the role of myosin in muscle contraction?

Back

Myosin heads attach to actin filaments and pull them inward, causing muscle contraction.

Front

What is a myofibril?

Back

A myofibril is a long, thread-like structure made up of repeating units called sarcomeres, responsible for muscle contraction.

Front

What is a muscle fiber?

Back

A muscle fiber is a single muscle cell that contains myofibrils and is capable of contraction.