chapter 7, skeletal muscle

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

b

A muscle that inserts on the radial tuberosity is most likely involved in a. protraction. b. elbow flexion. c. elbow abduction. d. elbow extension. e. pronation.

b

A resting muscle generates most of its ATP by a. anaerobic respiration. b. aerobic respiration. c. heat loss. d. glycolysis. e. conversion of creatine phosphate.

b

During which phase is the stimulus frequency so high that the relaxation phase is eliminated? a. incomplete tetanus b. complete tetanus c. a twitch d. recovery e. recruitment

b

Glycolysis a. occurs in the nucleus. b. is an anaerobic process. c. is the breakdown of pyruvate to glucose. d. is only active during rest. e. acts as the only source of ATP in muscle tissue.

b

The muscle that adducts and medially rotates the shoulder is the a. trapezius. b. teres major. c. teres minor. d. deltoid. e. infraspinatus.

b

Which statement regarding skeletal muscle is true? a. Skeletal muscles do not contain connective tissue. b. Skeletal muscles contain blood vessels. c. Skeletal muscles do not contain nervous tissue. d. Skeletal muscles are directly, but not indirectly, attached to bones. e. Skeletal muscles do not maintain body temperature.

b

A muscle ________ contains a sarcolemma, sarcoplasm, myofilaments, and myofibrils. a. motor end plate b. myofibril c. fiber d. T-tubule e. intercalated disc

c

Acetylcholinesterase is found within the ________. a. sarcomere b. nucleus c. synaptic cleft d. myofibril e. sarcolemma

c

Each myofibril consists of approximately ________ sarcomeres. a. 500 b. 10 c. 10,000 d. 100,000 e. 2-3 million

c

Muscle fascicles are separated by a. epimysium. b. endomysium. c. perimysium. d. sarcolemma. e. periosteum.

c

Regarding a skeletal muscle fiber, wherever a T-tubule encircles a myofibril, the tubule is tightly bound to a. the sarcolemma. b. thick filaments. c. the sarcoplasmic reticulum. d. the nucleus. e. the endomysium.

c

Smooth muscle a. does not undergo tetanus. b. is not resistant to fatigue. c. uses primarily aerobic metabolism. d. contracts faster than skeletal muscle. e. does not use calcium.

c

The area between Z lines is the a. sarcoplasmic reticulum. b. myofilament. c. sarcomere. d. myofibril. e. sarcolemma.

c

The area of the sarcomere that is the light region between two successive A-bands is the a. Z line. b. H band. c. I band. d. M line. e. myofibril.

c

The muscle that compresses the cheeks, as when pursing the lips and blowing forcefully, is the ________. a. orbicularis oris b. zygomaticus minor c. buccinator d. masseter e. temporalis

c

A person whose genetic makeup makes him or her a better marathon runner than a sprinter probably has more ________ in his or her leg muscles. a. intermediate fibers b. red fibers c. dark fibers d. slow fibers e. fast fibers

d

A single stimulus-contraction-relaxation sequence in a muscle fiber is known as a(n) ________. a. summation b. latent period c. incomplete tetanus d. twitch e. complete tetanus

d

During moderate activity, which of the following is true regarding muscle metabolism? a. Mitochondrial activity provides about one-third of the ATP consumed. b. Most ATP is produced through glycolysis, with lactate and hydrogen ions as byproducts. c. The ATP produced is used to build energy reserves of ATP and glycogen. d. Glucose and fatty acids are catabolized. e. Mitochondria are not involved.

d

In infants, which muscle produces suction for suckling at the breast? a. orbicularis oris b. levator labii c. risorius d. buccinator e. masseter

d

Myofibrils are made primarily of a. tropomyosin. b. ATP and ADP. c. epimysium. d. actin and myosin. e. troponin.

d

Neurotransmitters that cause skeletal muscle contraction are normally stored in a. motor end plates. b. actin. c. motor units. d. motor neuron axon terminals. e. myofibrils.

d

Regarding lactic acid regulation, which cells in the body consume extra oxygen and produce ATP for the conversion of excess lactate absorbed from the blood back to glucose? a. cardiac muscle cells b. neurons c. erythrocytes d. liver cells e. skeletal muscle fibers

d

Skeletal muscle fibers differ from "typical cells" in that these muscle fibers a. lack mitochondria. b. are very small. c. lack a plasma membrane. d. have many nuclei. e. contain endoplasmic reticulum.

d

Smooth muscle cells a. are innervated by motor neurons. b. are multinucleate. c. contain intercalated discs. d. are spindle-shaped. e. are larger than cardiac muscle cells.

d

The muscle that adducts and rotates the scapula laterally is the a. serratus anterior. b. subclavius. c. pectoralis minor. d. rhomboid. e. levator scapulae.

d

A layer of collagen fibers that surrounds an entire muscle is called a. perimysium. b. sarcomere. c. sarcolemma. d. endomysium. e. epimysium.

e

A sheath of connective tissue surrounding a bundle of striated muscle fibers is called ________. a. perimysium b. epimysium c. sarcolemma d. sarcoplasmic reticulum e. endomysium

a

Exhaustion of energy reserves or decline in pH due to production and dissociation of lactic acid causes a. muscle fatigue. b. the striated appearance of skeletal muscle. c. muscle contraction. d. the conduction of neural information to the muscle fiber. e. muscle relaxation.

a

Fast fibers a. have high glycogen reserves. b. have a high concentration of myoglobin. c. are about half the diameter of slow fibers. d. have loosely packed myofibrils. e. have many mitochondria.

a

Muscle cells a. can only contract. b. actively lengthen. c. generate compression. d. possess a mechanism that regulates the tension amount by changing the number of contracting sarcomeres. e. vary tension production based on the amount of sodium ions bound to actin.

a

Nonstriated, involuntary muscle is a. smooth. b. intermediate skeletal. c. white skeletal. d. cardiac. e. red skeletal

a

The deltoid acts to a. abduct the arm. b. laterally rotate the shoulder. c. flex the wrist. d. medially rotate the shoulder. e. adduct the arm.

a

During activities requiring aerobic endurance, a. amino acids are not broken down. b. glycogen and glycolysis are the primary sources of reserve energy. c. muscle hypertrophy often occurs. d. fatigue occurs in a few minutes. e. most of the muscle's energy is produced in mitochondria

e

The striated appearance of skeletal muscle results from a. the sarcoplasmic reticulum. b. cisternae placement. c. the transverse tubule pattern. d. the perimysium arrangement. e. actin and myosin arrangement.

e