CHAPTER 6 MUSCULAR SYSTEM

Type of movement that turns the sole of the foot medially

inversion

Type of movement that points the toes

plantar flexion

What is the unstoppable electrical current that travels down the length of the entire surface of a sarcolemma? A. Neuromuscular junction B. Action potential C. Neurotransmitter D. Acetylcholine

B. Action potential

The method that regenerates the most ATP during muscle activity is ______________ A. direct phosphorylation B. aerobic pathway C. anaerobic pathway D. lactic acid pathway

B. aerobic pathway

Striated involuntary muscle tissue is classified as ________ muscle. A. skeletal B. cardiac C. smooth D. either smooth or skeletal

B. cardiac

the structural and functional unit of a skeletal muscle is known as _________ A. sarcolemma B. sarcomere C. myofilament D. sarcoplasm E. sarcoplasmic reticulum

B. sarcomere

What is covered by the endomysium? A. fascicles of muscle cells B. an entire muscle C. an individual muscle cells D. myofibrils E. smooth muscle only

C. an individual muscle cells

Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ___________ A. elasticity B. irritability C. contractility D. extensibilty

C. contractility

Leaning against an immovable wall while waiting for a bus is a type of_________ A. isotonic contraction B. twitch C. isometric contraction D. resistance exercise

C. isometric contraction

Which of the following muscles are antagonists? A. biceps brachii and triceps brachii B. biceps femoris and biceps brachii C. Vastus medialis and vastus lateralis D. Masseter and temporalis E. Gastrocnemius and soleus

A. biceps brachii and triceps brachii

The arrangement of fascicles in orbicularis oris is ________ A. circular B. convergent C. pennate D. fusiform

A. circular

A smooth, sustained contraction, with no evidence of relaxation, is called ________ A. fused, or complete, tetanus B. a twitch C. unfused, or incomplete, tetanus D. summing of contractions

A. fused, or complete, tetanus

According to the sliding filament theory, how does muscle contraction occur? A. myosin heads form cross bridges and pull thin filaments, causing them to slide B. both thick and thin filaments shorten as the muscle contracts C. a bands bunch up and shorten as myosin heads attach to thin filaments D. myosin heads attach and detach from thin filaments, causing thin filaments to shorten

A. myosin heads from cross bridges and pull thin filaments, causing them to slide

Which of the following is composed mostly of the protein myosin? A. thick filaments B. thin filaments C. all myofilaments D. Z discs E. light bands

A. thick filaments

Which method of regenerating ATP during muscle contraction can produce lactic acid?

anaerobic glycolysis

What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue? A. sarcoplasm and sarcolemma B. Thick filaments and myosin heads C. A bands and I bands D. H zones and M lines E. Z discs and H zones

C. A bands and I bands

While doing "jumping jacks" during an exercise class, your arms and legs move laterally away from the midline of your body. This motion is called:______ A. extension B. flexion C. abduction D. adduction E. circumduction

C. abduction

Arrange the steps involved in the development of an action potential in the neuromuscular junction from start to end A. calcium channels open, and calcium ions enter the axon terminal causing synaptic vesicles to release ACh B. depolarization opens more sodium channels that allow sodium ions to enter the cell C. acetylcholinesterase (AChE) breaks down acetylcholine into acetic acid and choline D. Nerve impulse reaches the axon terminal of the motor neuron E. ACh diffuses across the synaptic cleft and attaches to receptors on the sarcolemma of the muscle cell

D, A, E, B, C

What organelle wraps and surrounds the myofibril and stores calcium? A. cross bridge B. sarcomere C. sarcolemma D. Sarcoplasmic reticulum

D. Sarcoplasmic reticulum

What is the main function of the quadriceps group? A. arm flexion B. hand supination C. thigh abduction D. knee extension E. foot inversion

D. knee extension

Which one of the following is not a criterion generally used in naming muscles? A. relative size of the muscle B. number of origins of the muscle C. Shape of the muscle D. Method of attachment of the muscle to bone E. Action of the muscle

D. method of attachment of the muscle to bone

The point of muscle attachment to an immovable or less movable bone is known as the ___________ A. innervation B. action C. insertion D. origin

D. origin

Which neurotransmitter is used by the nervous system to activate skeletal muscle cell? A. Potassium ions B. Cross bridges C. Calcium ions D. Sarcoplasmic reticulum E. Acetylcholine

E. Acetylcholine

Which muscle of the lateral thigh is the favored site for intramuscular injections?

Vastus lateralis

Type of movement that decreases the angle of the joint

flexion