The Essentials of Human Anatomy and Physiology: Chapter 6 Practice Test (The Muscular System)

What is the specific neurotransmitter that is released by motor neurons and stimulates skeletal muscle? Endomysium Dopamine GABA Acetylcholine (Ach) Epinephrine

Acetylcholine (Ach)

Which of the following statements is NOT true regarding energy generation for muscle contraction? Aerobic respiration refers to metabolic pathways that use oxygen. At rest and during light exercise, ATP is regenerated almost entirely by metabolic pathways that use oxygen. One of the pathways for ATP regeneration is direct phosphorylation of ADP by creatine phosphate. The initial steps of glucose breakdown occur via a pathway called glycolysis, which does not use oxygen, and is an anaerobic part of the metabolic pathway. Anaerobic glycolysis is not an energy source for muscle contraction.

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? Cardiac muscle, unlike smooth muscle, is involuntary. Cardiac muscle, unlike smooth muscle, has peripheral nuclei. Cardiac muscle has a single nucleus; smooth muscle has peripheral nuclei. Cardiac muscle is striated.

Cardiac muscle is striated.

Which of these muscles is located in the abdominal region? External oblique Rectus femoris Biceps femoris Biceps brachii Latissimus dorsi

External oblique

Which of the following refers to one neuron and all the skeletal muscle cells it stimulates? Neuromuscular junction Irritability and contractility Muscle fiber Motor unit Synaptic cleft

Motor unit

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

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

Which of the following statements is NOT true? 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. Tetanic contractions of muscles are smooth and prolonged muscle contractions, which can be slight or vigorous depending on what work has to be done. Tetanic contraction of muscles refers to a disease that causes total, sustained contraction of muscles. Complete tetanus is a smooth continuous contraction without any evidence of relaxation, and results from a very rapid rate of stimulation. Tetanic contraction is normal and desirable, and is quite different from the pathologic condition of tetanus.

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

What is the BEST definition of the origin of a muscle? The proximal attachment of the muscle to a bone The attachment of the muscle to a bone The distal attachment of the muscle to a bone The attachment of the muscle to a bone that is relatively fixed The attachment of the muscle to a bone that is relatively movable

The attachment of the muscle to a bone that is relatively fixed

Which of the following statements is NOT true regarding muscle attachments and body movements? When the foot is dorsiflexed, the foot is flat on the ground. In circumduction of the arm, the distal end of the limb describes a cone. Flexion is a movement that generally occurs in the sagittal plane and decreases the angle of the joint, bringing the two bones closer together. The point of attachment of a muscle to the immovable, or less movable, bone is called the origin. Abduction is movement away from the body, which occurs in the coronal plane.

When the foot is dorsiflexed, the foot is flat on the ground.

In a skeletal muscle fiber, the sarcomere is a repetitive unit that consists of the entire region between the _______. I bands Z lines M lines A bands H zones

Z lines The sarcomere is a contractile unit of muscle, which is the area between successive Z lines.

The bending or movement of a limb toward the midline of the body is known as _______. extension pronation abduction flexion adduction

adduction

The muscle that facilitates flexion of the forearm is the _______. triceps brachii rectus femoris biceps femoris biceps brachii buccinator

biceps brachii

Muscles that are concerned with bracing actions are called _______. antagonists extensors fixators pronators flexors

fixators

The anatomical term for a muscle cell, in skeletal and smooth muscle tissues, is _______. sarcomere sarcolemma muscle fiber myofilament myofibril

muscle fiber

The nuclei of skeletal muscle cells are pushed aside by long, ribbonlike organelles called _______, which nearly fill the cytoplasm. sarcolemma sarcoplasmic reticulum myofibrils myofilaments sarcomeres

myofibrils

The muscle that is mainly responsible for a particular movement is known as the _______. fixator prime mover pronator synergist antagonist

prime mover The prime mover is the muscle that is responsible for causing a particular movement.

The plasma membrane of a muscle cell is most usually termed a _______. intercalated disc sarcoplasm sarcoplasmic reticulum sarcomere sarcolemma

sarcolemma

A tissue with striations and many flattened nuclei under the plasma membrane in each cell would be called _______. cardiac muscle smooth muscle visceral muscle skeletal muscle

skeletal muscle

The endomysium is a delicate connective tissue sheath that surrounds a/an _______. bundle of cardiac muscle fibers bundle of smooth muscle fibers fascicle entire skeletal muscle skeletal muscle fiber

skeletal muscle fiber

The muscle whose action is dorsiflexion and inversion of the foot is the _______. tibialis anterior rectus femoris sartorius peroneus muscles biceps femoris

tibialis anterior