23-24 Muscular System Test

Name:

Which of the following statements about muscle tissue is NOT correct?

• an individual muscle cell is called a muscle fiber
• in muscle cells, the cytoplasm is called the sarcoplasm
• the sarcomere is the space between the thick and thin filaments
• the actin filaments are the ones that actually slide during contraction

Which of the following statements is NOT true of skeletal muscle activity?

• typically, muscles cross at least one joint
• the bulk of the muscle lies proximal to the joint crossed
• all muscles have at least two attachments
• during contraction, the muscle origin moves towards the insertion

Which number most closely approximates the number of skeletal muscles in the human body?

• 206
• 640
• about a 1,000
• several thousand

The heads of the myosin filaments are called __ when they link the thick and thin filaments together during skeletal muscle contraction.

• sarcoplasm
• sarcomeres
• crossbridges
• sliding filaments

The sliding filament theory involves the sliding of the __ during skeletal muscle contraction as each crossbridge attaches and detaches several times.

• myosin heads
• actin filaments
• neuromuscular junction
• sarcomere

The connective tissue covering that surrounds an entire muscle is

• endomysium
• perimysium
• tendon
• epimysium

Which of the following is NOT a function of the muscular system?

• production of movement
• stabilization of joints
• hematopoiesis
• generation of heat

The condition of skeletal muscle fatigue can be best explained by

• the all-or-none law
• the inability of muscles to contract for an extended period of time
• the result of oxygen debt
• increased blood supply to the muscle during strenuous exercise

Which of the following statements is NOT true?

• Muscles can only pull.
• Contractility refers to the muscles ability to shorten.
• When a muscle relaxes, it pushes on the insertion.
• Isotonic contractions result in sliding myofilaments and muscle movement.