chapter 6 muscles

The point of muscle attachment to an immovable or less movable bone is known as the ________. Select one: a. origin b. innervation c. insertion d. action

a. origin

What is the main function of the quadriceps group? Select one: a. foot inversion b. knee extension c. arm flexion d. thigh abduction e. hand supination

b. knee extension

Which of these events must occur first to trigger the skeletal muscle to generate an action potential and contract? Select one: a. sodium ions rush into the cell b. acetylcholinesterase (AchE) breaks down acetylcholine (ACh) c. acetylcholine (ACh) causes temporary permeability to sodium d. operation of the sodium-potassium pump e. diffusion of potassium ions out of the cell

c. acetylcholine (ACh) causes temporary permeability to sodium

In order to excite a muscle cell, acetycholine must ________. Select one: a. travel into the axon terminal of the nerve cell by endocytosis b. enter the muscle cell through protein channels c. bind to receptors in the sarcolemma of the muscle cell d. break down acetylcholinesterase in the synaptic cleft e. enter the muscle cell by endocytosis

c. bind to receptors in the sarcolemma of the muscle cell

Which of the following is an example of an isometric contraction? Select one: a. pushing against an immovable wall b. rotating the arm c. bending the elbow d. nodding the head as to say "yes" e. shaking the head as to say "no

a. pushing against an immovable wall

Which of the following can actually shorten during a muscle contraction? Select one: a. sarcomere b. actin filament c. myosin filament d. A band e. myofilament

a. sarcomere

The epimysium covering on the outside of the muscle can blend into cordlike ________ or sheetlike ________. Select one: a. fascia; ligaments b. tendons; aponeuroses c. ligaments; tendons d. aponeuroses; ligaments

b. tendons; aponeuroses

What is the origin of the deltoid muscle? Select one: a. proximal radius b. olecranon process of ulna c. scapular spine and clavicle d. distal humerus e. proximal humerus

c. scapular spine and clavicle

Which type of muscle tissue contracts most quickly upon stimulation? Select one: a. tendons b. cardiac c. skeletal d. visceral e. smooth

c. skeletal

The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the ________. Select one: a. cross bridge b. sarcomere c. synaptic cleft d. neuromuscular junction e. motor unit

c. synaptic cleft

A muscle group that works with and assists the action of a prime mover is a(n) ________. Select one: a. antagonist only b. antagonist and synergist c. synergist only d. antagonist and fixator e. fixator only

c. synergist only

Cross bridges are created when myosin heads bind to ________. Select one: a. myosin filaments b. sarcomeres c. thin filaments d. thick filaments e. sarcoplasmic reticula

c. thin filaments

The muscle fiber (cell) is indicated by ________. Select one: a. Label B b. Label A c. Label D d. Label C

d

Contractions in which muscles shorten and produce movement are known as ________. Select one: a. twitches b. resistance exercises c. isometric contractions d. isotonic contractions

d isotonic

Acetylcholine is ________. Select one: a. an oxygen-binding protein b. an ion pump on the postsynaptic membrane c. a source of energy for muscle contraction d. a neurotransmitter that stimulates skeletal muscle e. a component of thick myofilaments

d. a neurotransmitter that stimulates skeletal muscle

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 ________. Select one: a. extension b. flexion c. circumduction d. abduction e. adduction

d. abduction

Muscles that perform opposite actions to one another are termed ________. Select one: a. synergists b. prime movers c. fixators d. antagonists

d. antagonists

What condition results if muscles are not used, such as when immobilized in a cast for healing a broken bone? Select one: a. lordosis b. scoliosis c. spina bifida d. atrophy e. hypertrophy

d. atrophy

Neurotransmitters are released upon stimulation from a nerve impulse by the ________. Select one: a. sarcolemma of the muscle cell b. sarcoplasmic reticulum c. thick filaments d. axon terminals of the motor neuron e. myofibrils

d. axon terminals of the motor neuron

The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscle contraction. Select one: a. motor units b. synapses c. neuromuscular junctions d. cross bridges

d. cross bridges

During skeletal muscle contraction, myosin heads attach to binding sites associated with ________. Select one: a. thick filaments b. the H zone c. myosin filaments d. Z discs e. actin filaments

e. actin filaments

Striated involuntary muscle tissue found in the heart is ________. Select one: a. dense regular b. dense irregular c. skeletal muscle d. smooth muscle e. cardiac muscle

e. cardiac muscle

Paralysis of which of the following would make an individual unable to flex the hip ________. Select one: a. soleus b. gastrocnemius c. biceps femoris d. tibialis anterior e. iliopsoas

e. iliopsoas

The least movable point of muscle attachment to a bone is termed its ________. Select one: a. bone marking b. action c. function d. insertion e. origin

e. origin

Anaerobic glycolysis occurs without ________. Select one: a. ATP b. carbon dioxide c. lactic acid d. glucose e. oxygen

e. oxygen

The plasma membrane of a skeletal muscle cell is called the ________. Select one: a. myofilament b. sarcoplasm c. sarcomere d. sarcoplasmic reticulum e. sarcolemma

e. sarcolemma

Which one of the following is composed of myosin protein? Select one: a. thin filaments b. light bands c. all myofilaments d. Z discs e. thick filaments

e. thick filaments

he mechanical force of contraction is generated by ________. Select one: a. a sliding of thin filaments past thick filaments b. the temporary disappearance of thin filaments c. the "accordian-like" folding of thin and thick filaments d. shortening of the thin filaments e. shortening of the thick filaments

a. a sliding of thin filaments past thick filaments

Why are calcium ions necessary for skeletal muscle contraction? Select one: a. calcium triggers the binding of myosin to actin b. calcium increases the action potential transmitted along the sarcolemma c. calcium binds to regulatory proteins on the myosin filaments, changing both their shape and their position on the thick filaments d. calcium releases the inhibition on Z discs e. calcium causes ATP binding to actin

a. calcium triggers the binding of myosin to actin

The prime mover of arm abduction is the ________ muscle. Select one: a. deltoid b. quadratus lumborum c. latissimus dorsi d. trapezius

a. deltoid

Which muscle group includes the biceps femoris, semimembranosus, and semitendinosus? Select one: a. hamstring group b. abdominal muscles c. quadriceps group d. adductor group e. fibularis muscles

a. hamstring group

Striated involuntary muscle tissue is classified as ________ muscle. Select one: a. either smooth or skeletal b. cardiac c. smooth d. skeletal

b cardiac

Endomysium covers ________. Select one: a. smooth muscle only b. an individual muscle cell c. myofibrils d. an entire muscle e. fascicles of muscle cells

b. an individual muscle cell

Which of the following muscles closes the jaw? Select one: a. sternocleidomastoid b. both masseter and temporalis c. frontalis d. buccinator e. zygomaticus

b. both masseter and temporalis

Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________. Select one: a. elasticity b. contractility c. extensibility d. irritability

b. contractility

Which one of the following muscles is involved in abduction of the arm at the shoulder joint? Select one: a. triceps brachii b. deltoid c. latissimus dorsi d. biceps brachii e. pectoralis majo

b. deltoid

The hamstring group is the prime mover of thigh ________ and knee ________. Select one: a. dorsiflexion; plantar flexion b. extension; flexion c. abduction; adduction d. rotation; circumduction

b. extension; flexion

A smooth, sustained contraction is called ________. Select one: a. summing of contractions b. fused, or complete, tetanus c. a twitch d. unfused, or incomplete, tetanus

b. fused, or complete, tetanus

Which of the following is NOT a function of the muscular system? Select one: a. production of movement b. hematopoiesis c. maintenance of posture d. stabilization of joints e. generation of heat

b. hematopoiesis

Smooth muscle cells are ________. Select one: a. cylindrical b. involuntary c. branched d. striated e. multinucleate

b. involuntary

The muscle that closes each eye is the ________. Select one: a. frontalis b. orbicularis oculi c. orbicularis oris d. zygomaticus

b. orbicularis oculi

Which muscle is an antagonist to gastrocnemius? Select one: a. fibularis longus b. tibialis anterior c. soleus d. fibularis brevis e. sartorius Clear my choice

b. tibialis anterior

The movement opposite to abduction is ________. Select one: a. circumduction b. flexion c. adduction d. supination e. rotation

c adduction

A nursing infant develops a powerful sucking muscle that adults also use for whistling or blowing a trumpet called the ________. Select one: a. platysma b. temporalis c. buccinator d. zygomaticus e. masseter

c. buccinator

A motor neuron and all of the skeletal muscle fibers it stimulates are termed a ________. Select one: a. myofilament b. neuromuscular junction c. motor unit d. synaptic cleft e. neurotransmitter

c. motor unit

An inherited disease that causes muscles to degenerate and atrophy is known as ________. Select one: a. cystic fibrosis b. torticollis c. muscular dystrophy d. myasthenia gravis

c. muscular dystrophy

A muscle located on the ventral (anterior) side of the body is the ________. Select one: a. latissimus dorsi b. gluteus medius c. pectoralis major d. occipitalis e. gastrocnemius

c. pectoralis major

Which muscle helps compress the abdominal contents during defecation or childbirth? Select one: a. internal intercostals b. deltoids c. rectus abdominis d. trapezius e. iliopsoas

c. rectus abdominis

Sandra is playing the piano for her recital. Which muscle is NOT involved in the movement of her hands and/or fingers ________. Select one: a. flexor carpi ulnaris b. extensor carpi radialis c. extensor digitorum d. extensor digitorum longus e. flexor carpi radialis

d. extensor digitorum longus

The condition of skeletal muscle fatigue can be best explained by ________. Select one: a. a total lack of ATP b. the all-or-none law c. the inability to generate sufficient quantities of ATP due to feedback regulation of synthesis d. insufficient intracellular quantities of ATP due to excessive consumption e. inadequate numbers of mitochondria

d. insufficient intracellular quantities of ATP due to excessive consumption

An elaborate and specialized network of membranes in skeletal muscle cells that function in calcium storage is the ________. Select one: a. sarcolemma b. intermediate filament network c. mitochondria d. sarcoplasmic reticulum e. myofibrillar network

d. sarcoplasmic reticulum

The ________ is an organelle that wraps and surrounds the myofibril and stores calcium. Select one: a. sarcolemma b. cross bridge c. sarcomere d. sarcoplasmic reticulum

d. sarcoplasmic reticulum

Which of these muscles is a synergist to masseter? Select one: a. orbicularis oris b. trapezius c. buccinator d. temporalis e. sternocleidomastoid

d. temporalis

A skeletal muscle twitch differs from a tetanic contraction in that ________. Select one: a. the muscle twitch occurs only in small muscles while a tetanic contraction occurs in large muscle groups b. the tetanic contraction is caused by a single stimulus, while the twitch is caused by very rapid multiple stimuli c. the tetanic contraction is considered abnormal, while the twitch is a normal muscle response d. the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous e. the muscle twitch is prolonged and continuous while a tetanic contraction is brief and "jerky"

d. the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous