Chapter 6: The Muscular System

Which of these muscles is located in the abdominal region? a. Latissimus dorsi b. Biceps brachii c. External oblique d. Rectus femoris

c. External oblique

Which of the following refers to one neuron and all the skeletal muscle cells it stimulates? a. Neuromuscular junction b. Synaptic cleft c. Motor unit d. Muscle fiber

c. Motor unit

In a skeletal muscle fiber, the sarcomere is a repetitive unit that consists of the entire region between the __________. a. I bands b. H zones c. Z discs d. A bands

c. Z discs

The bending or movement of a limb toward the midline of the body is known as __________. a. extension b. flexion c. adduction d. abduction

c. adduction

Consider the two types of muscle contractions described in this chapter; in __________ contractions, the muscle may shorten and movement may occur. a. anaerobic b. isometric c. isotonic d. fatigued

c. isotonic

The muscle that is mainly responsible for a particular movement is known as the __________. a. fixator b. pronator c. prime mover d. synergist

c. prime mover

The plasma membrane of a muscle cell is most usually termed a __________. a. sarcoplasmic reticulum b. sarcomere c. sarcolemma d. sarcoplasm

c. sarcolemma

An important medical injection site in the hip is the __________. a. vastus lateralis b. gluteus maximus c. gluteus minimus d. gluteus medius

d. gluteus medius

A fascicle is wrapped by a layer of connective tissue called __________. a. tendons b. endomysium c. epimysium d. perimysium

d. perimysium

Which of the following statements is NOT true regarding energy generation for muscle contraction? a. Anaerobic glycolysis is not an energy source for muscle contraction. b. At rest and during light exercise, ATP is regenerated almost entirely by metabolic pathways that use oxygen. c. Aerobic respiration refers to metabolic pathways that use oxygen. d. One of the pathways for ATP regeneration is direct phosphorylation of ADP by creatine phosphate.

a. Anaerobic glycolysis is not an energy source for muscle contraction.

Which of the following can best be used to distinguish cardiac muscle from smooth muscle? a. Cardiac muscle is striated. b. Cardiac muscle, unlike smooth muscle, has peripheral nuclei. c. Cardiac muscle has a single nucleus; smooth muscle has peripheral nuclei. d. Cardiac muscle, unlike smooth muscle, is involuntary.

a. Cardiac muscle is striated.

Although ATP provides the energy for muscle contraction, __________ must also be present for muscle fibers to slide properly during contraction. a. calcium b. copper c. chlorine d. zinc

a. calcium

The anatomical term for a muscle cell, in skeletal and smooth muscle tissues, is __________. a. muscle fiber b. myofilament c. sarcomere d. sarcolemma

a. muscle fiber

The three types of muscle tissue are skeletal, cardiac, and __________. a. smooth b. irregular c. banded d. aerobic

a. smooth

The muscle that facilitates flexion of the forearm is the __________. a. biceps femoris b. biceps brachii c. buccinator d. triceps brachii

b. biceps brachii

The essential function of any muscle is to __________. a. relax b. contract c. lengthen d. push

b. contract

Muscles that are concerned with bracing actions are called __________. a. flexors b. fixators c. pronators d. extensors

b. fixators

Exercise throughout life helps muscles to retain both strength and __________. a. atrophy b. mass c. mineral deposition d. color

b. mass

Referring to the muscle attachment to bones, the __________ is the immovable attachment site. a. midline b. origin c. insertion d. extension

b. origin

Considering the relationship between the biceps and the triceps, the biceps is the __________ whereas the triceps is the __________ as the elbow is flexed. a. fixator; antagonist b. prime mover; antagonist c. antagonist; prime mover d. prime mover; fixator

b. prime mover; antagonist

The endomysium is a delicate connective tissue sheath that surrounds a/an __________. a. fascicle b. skeletal muscle fiber c. entire skeletal muscle d. bundle of smooth muscle fibers

b. skeletal muscle fiber

The muscle whose action is dorsiflexion and inversion of the foot is the __________. a. sartorius b. tibialis anterior c. biceps femoris d. rectus femoris

b. tibialis anterior

Which of the following statements is NOT true? a. Tetanic contractions of muscles are smooth and prolonged muscle contractions, which can be slight or vigorous depending on what work has to be done. b. Tetanic contraction is normal and desirable, and is quite different from the pathologic condition of tetanus. c. Tetanic contraction of muscles refers to a disease that causes total, sustained contraction of muscles. d. When a muscle is stimulated so rapidly that no evidence of relaxation is seen and the contractions are completely smooth and sustained, the muscle is said to be in tetanus or in tetanic contraction.

c. Tetanic contraction of muscles refers to a disease that causes total, sustained contraction of muscles.

The neurotransmitter __________ is vital to proper muscle functioning. a. endorphin b. serotonin c. acetylcholine d. dopamine

c. acetylcholine

Which of the following is NOT a function of skeletal muscle? a. Generates heat b. Maintains posture c. Produces movement d. Participates in the transport of oxygen in the blood to the tissues

d. Participates in the transport of oxygen in the blood to the tissues