Quiz 5

Dorsiflexion involves ________ at the ankle joint and ________ of the foot. A. adduction; flexion of the heel B. flexion; elevation of the heel C. extension; elevation of the heel D. flexion; elevation of the sole E. extension; flexion of the sole

flexion; elevation of the sole

Glycolysis A. occurs in the nucleus. B. acts as the only source of ATP in muscle tissue. C. is the breakdown of pyruvate to glucose. D. is an anaerobic process. E. is only active during rest.

is an anaerobic process

Which of the following events most directly occurs due to an action potential generated by the motor neuron? A. AChE breaks down ACh in the synaptic cleft. B. ACh is released at the synaptic cleft. C. Na+Na+ rushes into the sarcolemma. D. ACh binds to ACh receptors. E. An action potential is generated on the muscle fiber.

ACh is released at the synaptic cleft

Smooth muscle cells A. are multinucleate. B. have to be innervated by motor neurons. C. are spindle-shaped. D. contain intercalated discs. E. are larger than cardiac muscle cells.

are spindle-shaped

Which of the following is characteristic of cardiac muscle? A. Cardiac muscle fibers are faster than skeletal muscles. B. Cardiac muscle cells achieve tetany with every contraction. C. Neurons that innervate cardiac muscle tissue are under voluntary control. D. Cardiac muscle cells are striated. E. Cardiac muscle fibers are multinucleated.

cardiac muscle cells are striated

As you unsuccessfully attempt to lift the 300-pound weights off the ground, you are demonstrating ________. A. hypotonic contraction B. isometric contraction C. hypertonic contraction D. isotonic contraction

isometric contraction

The generation of an action potential in the sarcolemma is short in duration. Which of the following explanations describes why the reaction of the sarcolemma is short in duration? A. ACh diffuses across the synaptic cleft toward the sarcolemma. B. The ACh receptors open ion channels in response to binding. C. Na+Na+ rushes into the cytoplasm of the muscle cell. D. AChE acts to break down the ACh in the synaptic cleft.

AChE acts to break down the ACh in the synaptic cleft

During the contraction cycle, which one of the following steps occurs? A. Calcium is released from the sarcoplasmic reticulum and binds to myosin. B. With removal of neural stimulation, calcium is quickly returned to the nucleus of the muscle cell. C. When ATP binds to myosin, it immediately causes a power stroke. D. During the power stroke, the myosin head shifts toward the M line of the sarcomere. E. Tropomyosin shifts to allow the binding site on myosin to be exposed to actin.

during the power stroke, the myosin head shifts toward the M line of the sarcomere

"Anaerobic endurance" A. is determined by the availability of carbohydrates, lipids, or amino acids for breakdown. B. does not promote muscle hypertrophy. C. is the length of time a muscle can continue to contract while supported by mitochondrial activities. D. is used during long, slow athletic activities. E. is exemplified by contractions of fast muscle fibers.

is exemplified by contractions of fast fibers

Fibrous cartilage discs that act as shock absorbers in joints are called ________. A. intervertebral discs B. synovial capsules C. bursae D. menisci E. tendons

menisci

Which of the following statements is true concerning motor units? A. Movement of the eyeball requires fewer muscle fibers with less tension being produced. B. A small number of muscle fibers with increased tension is needed in large, gross movements. C. A motor unit consists of all the muscle fibers it controls as well as the area of the spinal cord where it originates. D. Lesser tension is required in lifting a dumbbell than in lifting a cup of coffee. E. An increased number of motor neurons is needed in precise movements such as lifting a cup of coffee than in lifting a dumbbell.

movement of the eyeball requires fewer muscle fibers with less tension being produced

Why do individual muscle twitches have to be added together, as in summation or tetanus? A. Only added twitches produce any muscle contraction: A fiber undergoing a muscle twitch does not contract at all. B. Multiple twitches add up to an increase in muscle fiber tension, which increases the strength of the muscle. C. Not enough acetylcholine will be produced for contraction without multiple twitches. D. There has to be a critical mass of muscle twitches for calcium to be released into the muscle cell. E. Not enough ATP is generated by one muscle twitch.

multiple twitches add up to an increase in muscle fiber tension, which increases the strength of the muscle

Which statement regarding "heat loss" is true? A. Muscle activity does not generate heat. B. When skeletal muscles are contracting at peak levels, body temperature drops. C. Shivering in a cold environment results in higher levels of heat loss. D. Heat loss is reduced when blood flow to the skin increases. E. Muscle contractions play an important role in the maintenance of normal body temperature.

muscle contractions play an important role in the maintenance of normal body temperature

Which statement regarding skeletal muscle is true? A. Skeletal muscles are directly, but not indirectly, attached to bones. B. Skeletal muscles do not contain connective tissue. C. Skeletal muscles do not contain nervous tissue. D. Skeletal muscles do not maintain body temperature. E. Skeletal muscles contain blood vessels.

skeletal muscles contain blood vessels

Why is the elbow joint considered to be extremely stable? A. Its relatively loose joint capsule permits an extensive range of motion. B. It has especially large and numerous bursae. C. Powerful muscles originating on the trunk, shoulder girdle, and humerus cover the joint capsule. D. A rotator cuff is associated with the joint. E. The bony surfaces of the humerus and ulna interlock.

the bony surfaces of the humerus and ulna interlock

Which of the following statements is true? A. The sarcolemma is the axon terminal membrane. B. Acetylcholinesterase (AChE) is stored in vesicles within the axon terminal of the motor neuron. C. The neurotransmitter is stored in the axon terminal of the motor neuron. D. The acetylcholine (ACh) receptors are located on the myofibril membrane.

the neurotransmitter is stored in the axon terminal of the motor neuron