Locomotion and Movement

Topics in this chapter

• Bones, Growth, and Bone Disorders
• Joints and Connective Supports
• Muscle Types and Specialized Movement
• Skeletal Muscle Contraction
• Neuromuscular Control and Energy

Cheat sheet

Practice questions

1. Question 1Q-3C2AAB

   Which sequence correctly describes the initiation of skeletal muscle contraction after a nerve impulse reaches the neuromuscular junction?

   1. A.Calcium ions bind to tropomyosin, which exposes the active sites on myosin.
   2. B.Calcium ions bind to troponin, causing tropomyosin to move away from the active sites on actin.
   3. C.ATP binds to actin and exposes the active sites on tropomyosin.
   4. D.Acetylcholine directly binds to myosin and causes actin filaments to shorten.
   See the answer and solution
2. Question 2Q-3EE73C

   Which change occurs in a sarcomere during contraction of a skeletal muscle fibre?

   1. A.The actin filaments shorten, while the myosin filaments remain unchanged.
   2. B.The A band decreases in length, while the I band remains unchanged.
   3. C.The I band and H zone decrease in width, while the A band remains unchanged.
   4. D.The A band, I band and H zone all decrease in width.
   See the answer and solution
3. Question 3Q-A7E1F5

   Which pair correctly matches a joint with its type?

   1. A.Joint between atlas and axis — hinge joint; shoulder joint — pivot joint
   2. B.Joint between atlas and axis — pivot joint; shoulder joint — ball-and-socket joint
   3. C.Elbow joint — ball-and-socket joint; wrist joint — pivot joint
   4. D.Sutures of the skull — freely movable joint; knee joint — fibrous joint
   See the answer and solution
4. Question 4Q-E87925

   A muscle fibre is deprived of ATP immediately after contraction. Which event is most likely to occur?

   1. A.Myosin heads detach rapidly from actin and the muscle relaxes.
   2. B.Calcium ions are actively pumped back into the sarcoplasmic reticulum.
   3. C.Myosin heads remain attached to actin, producing a state of stiffness.
   4. D.Tropomyosin permanently exposes all active sites on actin.
   See the answer and solution
5. Question 5Q-E8AF50

   Which structure primarily enables locomotion of a human sperm?

   1. A.Cilium
   2. B.Flagellum
   3. C.Pseudopodium
   4. D.Sucker
   See the answer and solution