Week 5 Muscular System Flashcards
The I band within a skeletal muscle fiber is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
B) Label B
The A band within a myofibril is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
A) Label A
The H zone, located within the A band, lacks thin filaments and is represented by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
D) Label D
The myofilament composed of actin is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
C) Label C
The epimysium is represented by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
A) Label A
The perimysium wraps a fascicle of muscle cells and is represented by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
C) Label C
The muscle fiber (cell) is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
B) Label B
The endomysium that wraps individual muscle fibers is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
D) Label D
Striated involuntary muscle tissue is classified as \_\_\_\_\_\_\_\_ muscle. A) skeletal B) cardiac C) smooth D) either smooth or skeletal
B) cardiac
Which term does not describe smooth muscle cells? A) Visceral B) Nonstriated C) Skeletal D) Involuntary
C) Skeletal
What organelle wraps and surrounds the myofibril and stores calcium? A) Cross bridge B) Sarcomere C) Sarcolemma D) Sarcoplasmic reticulum
D) Sarcoplasmic reticulum
Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as \_\_\_\_\_\_\_\_. A) elasticity B) irritability C) contractility D) extensibility
C) contractility
One neuron and all the skeletal muscles it stimulates is known as a \_\_\_\_\_\_\_\_. A) sarcoplasmic reticulum B) motor unit C) synaptic cleft D) neuromuscular junction
B) motor unit
The heads of the myosin myofilaments are called ________ when they link the thick and thin
filaments together during skeletal muscle contraction.
A) neuromuscular junctions
B) synapses
C) cross bridges
D) motor units
C) cross bridges
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
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 form cross bridges and pull thin filaments, causing them to slide.
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
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
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
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
Lead poisoning can cause a condition known as wrist drop in which the wrist is pronated or \_\_\_\_\_\_\_\_. A) the palms face posteriorly B) the palms face medially C) the palms face anteriorly D) the elbow flex
A) the palms face posteriorly
The arrangement of fascicles in orbicularis oris is \_\_\_\_\_\_\_\_. A) circular B) convergent C) pennate D) fusiform
A) circular
Which facial muscle is considered the "smiling" muscle since it raises the corners of the mouth? A) Orbicularis oris B) Frontalis C) Orbicularis oculi D) Zygomaticus
D) Zygomaticus
The prime mover of arm abduction is the \_\_\_\_\_\_\_\_ muscle. A) trapezius B) deltoid C) triceps brachii D) biceps brachii
B) deltoid
Jason injured his hamstring muscle group during football practice. He will be unable to perform \_\_\_\_\_\_\_\_. A) thigh extension and knee flexion B) dorsiflexion C) thigh abduction and adduction D) leg rotation and plantar flexion
A) thigh extension and knee flexion
An inherited disease that causes muscles to degenerate and atrophy is known as \_\_\_\_\_\_\_\_. A) torticollis B) muscular dystrophy C) cystic fibrosis D) myasthenia gravis
B) muscular dystrophy
Striated involuntary muscle tissue found in the heart is \_\_\_\_\_\_\_\_. A) smooth muscle B) skeletal muscle C) dense regular D) cardiac muscle E) dense irregular
D) cardiac muscle
What is covered by the endomysium? A) Fascicles of muscle cells B) An entire muscle C) An individual muscle cell D) Myofibrils E) Smooth muscle only
C) An individual muscle cell
The type of muscle tissue pictured in Figure 6.3 is \_\_\_\_\_\_\_\_. A) skeletal muscle B) voluntary C) striated D) found only in the heart E) smooth muscle
E) smooth muscle
The plasma membrane of a skeletal muscle cell is called the \_\_\_\_\_\_\_\_. A) sarcolemma B) sarcomere C) myofilament D) sarcoplasm E) sarcoplasmic reticulum
A) sarcolemma
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
Which type of filament is anchored to the Z disc within a myofibril? A) Thin filaments B) H zone C) Thick filaments D) Myosin filaments E) Cross bridges
A) Thin filaments
Which of the following is not a function of the muscular system? A) Production of movement B) Maintenance of posture C) Stabilization of joints D) Generation of heat E) Blood cell formation
E) Blood cell formation
A sarcomere is ________.
A) the nonfunctional unit of skeletal muscle
B) the contractile unit between two Z discs
C) the area between two intercalated discs
D) the wavy lines on the cell, as seen in a microscope
E) a compartment in a myofilament
B) the contractile unit between two Z discs
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
What is released by axon terminals into the synaptic cleft to stimulate a muscle to contract? A) Potassium ions B) Actin C) Sodium ions D) Neurotransmitter E) Myosin heads
D) Neurotransmitter
Which organelle stores calcium in muscle fibers? A) Myofibril B) Sarcoplasmic reticulum C) Sarcolemma D) Myofilament E) Sarcoplasm
B) Sarcoplasmic reticulum
Why are calcium ions necessary for skeletal muscle contraction?
A) Calcium ions increase the speed of the action potential transmitted along the sarcolemma.
B) Calcium ions release the inhibition on Z discs.
C) Calcium ions trigger the binding of myosin heads to actin filaments.
D) Calcium ions cause ATP binding to actin.
E) Calcium ions bind to regulatory proteins on the myosin filaments, changing both their shape
and their position on the thick filaments.
C) Calcium ions trigger the binding of myosin heads to actin filaments.
What is required to form a cross bridge between a myosin head and an actin filament? A) Potassium ions B) Sodium ions C) Calcium ions and ATP D) Sodium ions and ATP E) Acetylcholine
C) Calcium ions and ATP
Pufferfish contain a venom known as tetrodotoxin (TTX), which makes sodium channels
stay closed. You’d expect a muscle cell treated with TTX to ________.
A) produce contractions that are stronger than normal.
B) produce action potentials in rapid sequence.
C) be unable to produce an action potential.
D) operate the sodium-potassium pump more slowly.
E) continue forming cross bridges.
C) be unable to produce an action potential.
The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the \_\_\_\_\_\_\_\_. A) motor unit B) sarcomere C) neuromuscular junction D) synaptic cleft E) cross bridge
D) synaptic cleft
Neurotransmitters are released upon stimulation from a nerve impulse from the \_\_\_\_\_\_\_\_. A) myofibrils B) sarcoplasmic reticulum C) thick filaments D) axon terminals of the motor neuron E) sarcolemma of the muscle cell
D) axon terminals of the motor neuron
What must rush into a muscle cell to promote its depolarization? A) Potassium ions B) Calcium ions C) Acetylcholine D) Sodium ions E) Acetylcholinesterase
D) Sodium ions
During skeletal muscle contraction, myosin heads bind actin filaments to form \_\_\_\_\_\_\_\_. A) Z discs B) cross bridges C) A bands D) I bands E) H zones
B) cross bridges
What enzyme breaks down acetylcholine into acetic acid and choline to prevent continued contraction of the muscle fiber? A) Potassium ions B) Cross bridges C) Calcium ions D) Sarcoplasmic reticulum E) Acetylcholinesterase
E) Acetylcholinesterase
Skeletal muscle, as a whole, can generate different amounts of force, and different degrees of
shortening, in response to stimuli. What is this concept called?
A) Graded response
B) Twitch
C) Fused, or complete, tetanus
D) Unfused, or incomplete, tetanus
E) Action potential
A) Graded response
Which of these events must occur first to trigger the skeletal muscle to generate an action potential and contract?
A) Sodium ions rush into the cell.
B) Acetylcholine (ACh) binds to receptors on the sarcolemma and allows passage of sodium ions
into the cell.
C) Potassium ions diffuse out of the muscle cell.
D) The sodium-potassium pump restores sodium and potassium back to their initial positions.
E) Acetylcholinesterase (AchE) breaks down acetylcholine (ACh).
B) Acetylcholine (ACh) binds to receptors on the sarcolemma and allows passage of sodium ions
into the cell.
A skeletal muscle twitch differs from a tetanic contraction in that ________.
A) the tetanic contraction is considered abnormal, while the twitch is a normal muscle response
B) the tetanic contraction is caused by a single stimulus, while the twitch is caused by very rapid
multiple stimuli
C) the muscle twitch is prolonged and continuous while a tetanic contraction is brief and “jerky”
D) the muscle twitch occurs only in small muscles while a tetanic contraction occurs in large
muscle groups
E) the muscle twitch is a brief and “jerky” movement, while the tetanic contraction is prolonged
and continuous
E) the muscle twitch is a brief and “jerky” movement, while the tetanic contraction is prolonged
and continuous
Creatine phosphate (CP) functions within the muscle cells by ________.
A) forming a temporary chemical compound with myosin
B) forming a chemical compound with actin
C) inducing a conformational change in the myofilaments
D) storing energy that will be transferred to ADP to resynthesize ATP as needed
E) storing energy that will be transferred to ATP to resynthesize ADP as needed
D) storing energy that will be transferred to ADP to resynthesize ATP as needed
The condition of skeletal muscle fatigue can be best explained by ________.
A) the all-or-none law
B) the inability to generate sufficient quantities of ATP due to feedback regulation of synthesis
C) the inability of the muscle to contract even if it is being stimulated
D) a total lack of ATP in the body
E) inadequate numbers of mitochondria in muscle cells
C) the inability of the muscle to contract even if it is being stimulated
The state of continuous partial muscle contractions is known as \_\_\_\_\_\_\_\_. A) muscle fatigue B) muscle tone C) oxygen deficit D) fused (complete) tetanus E) twitch
B) muscle tone
Which method of regenerating ATP during muscle contraction can produce lactic acid? A) Aerobic respiration B) Oxidative phosphorylation C) Direct phosphorylation D) Creatine phosphate E) Anaerobic glycolysis
E) Anaerobic glycolysis
Which movement is antagonistic to extension? A) Flexion B) Rotation C) Circumduction D) Adduction E) Supination
A) Flexion
Which of the following muscles acts as a synergist to the masseter and closes the jaw? A) Buccinator B) Zygomaticus C) Frontalis D) Sternocleidomastoid E) Temporalis
E) Temporalis
Sandra is playing the piano for her recital. Which muscle is not involved in the movement of her hands and/or fingers? A) Flexor carpi radialis B) Flexor carpi ulnaris C) Extensor digitorum D) Extensor digitorum longus E) Extensor carpi radialis
D) Extensor digitorum longus
Which of these muscles is the prime mover of elbow extension? A) Brachialis B) Latissimus dorsi C) Deltoid D) Triceps brachii E) Biceps brachii
D) Triceps brachii
Which of these muscles is located on the ventral (anterior) side of the body? A) Pectoralis major B) Occipitalis C) Gastrocnemius D) Gluteus medius E) Latissimus dorsi
A) Pectoralis major
A nursing infant develops a powerful sucking muscle that adults also use for whistling or blowing a trumpet called the \_\_\_\_\_\_\_\_. A) platysma B) masseter C) zygomaticus D) buccinator E) temporalis
D) buccinator
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 muscle forms the curved calf of the posterior leg? A) Fibularis longus B) Gastrocnemius C) Rectus femoris D) Tibialis anterior E) Soleus
B) Gastrocnemius
Which muscle group adducts the thighs? A) Gluteus muscles B) Adductor group C) Hamstring group D) Quadriceps group E) Fibularis muscles
B) Adductor group
Which muscle group includes the biceps femoris, semimembranosus, and semitendinosus? A) Abdominal muscles B) Quadriceps group C) Adductor group D) Fibularis muscles E) Hamstring group
E) Hamstring group
Paralysis of which of the following would make an individual unable to flex the hip? A) Biceps femoris B) Gastrocnemius C) Tibialis anterior D) Soleus E) Iliopsoas
E) Iliopsoas
Which of the following consists of two large, flat muscles that cover the lower back? A) Deltoid B) Biceps brachii C) Triceps brachii D) Latissimus dorsi E) Pectoralis major
D) Latissimus dorsi
Like the biceps brachii muscle, which muscle is a prime mover in elbow flexion? A) Triceps brachii B) Deltoid C) Brachioradialis D) Fibularis longus E) Brachialis
E) Brachialis
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
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
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
Prior to surgery, a patient will be given a muscle relaxant. Evaluate the following drug descriptions and select the one that will promote muscle relaxation.
A) Drug A increases an influx of calcium ions into the axon terminal.
B) Drug B inhibits the breakdown of acetylcholine by preventing acetylcholinesterase from
acting.
C) Drug C decreases the binding of acetylcholine to its receptor.
D) Drug D increases the release of calcium from the sarcoplasmic reticulum.
E) Drug E promotes an increase in acetylcholine from synaptic vesicles.
C) Drug C decreases the binding of acetylcholine to its receptor.
Botulinum toxin is produced by bacteria; it can cause flaccid paralysis in human muscle cells. Evaluate the following mechanisms to determine its mode of action.
A) Botulinum toxin prevents the release of acetylcholinesterase.
B) Botulinum toxin promotes the release of acetylcholine from axon terminals.
C) Botulinum toxin prevents the release of acetylcholine from axon terminals.
D) Botulinum toxin prevents the exit of potassium ions from muscle cells.
E) Botulinum toxin promotes the entry of sodium ions into muscle cells.
C) Botulinum toxin prevents the release of acetylcholine from axon terminals.
An elderly man fell down his stairs and was diagnosed with an injury to his tibialis anterior muscle. Evaluate the following actions to determine how his mobility will be impaired in the coming weeks. A) Moving the foot down while walking B) Bending his knee C) Extending his knee D) Moving the foot up while walking E) Flexing the thigh
D) Moving the foot up while walking
Cardiac and skeletal muscle both possess striations.
TRUE/FALSE
TRUE
Cardiac muscle fibers are joined by special gap junctions called intercalated discs; these discs
allow heart activity to be closely coordinated.
TRUE/FALSE
TRUE
Smooth muscle cells produce movement of the body and generate heat.
TRUE/FALSE
FALSE
The striations seen in skeletal muscle are actually alternating dark A and light I bands.
TRUE/FALSE
TRUE
The sarcoplasmic reticulum wraps like a sleeve around the myofibril and stores and releases calcium.
TRUE/FALSE
TRUE
A neuromuscular junction consists of one neuron and all the skeletal muscles it stimulates.
TRUE/FALSE
FALSE
The neurotransmitter used by the nervous system to activate skeletal muscle cells is
acetylcholine.
TRUE/FALSE
TRUE
Strychnine is a neurotoxin found in rat poison. Since it prevents muscle contractions, strychnine functions by inhibiting acetylcholinesterase.
TRUE/FALSE
FALSE
The formation of cross bridges requires both calcium ions and ATP.
TRUE/FALSE
TRUE
The fastest mechanism for producing ATP is aerobic respiration.
TRUE/FALSE
FALSE
All muscles have at least two attachments: the origin and the insertion.
TRUE/FALSE
TRUE
Fixators are specialized synergists that stabilize the origin of prime movers so tension can be
used to move the insertion bone.
TRUE/FALSE
TRUE
A muscle that crosses on the lateral side of a joint produces abduction
TRUE/FALSE
TRUE
Abduction and adduction are antagonistic actions.
TRUE/FALSE
TRUE
The deltoid is a prime mover of arm adduction.
TRUE/FALSE
FALSE
The deltoid is a prime mover of arm adduction.
TRUE/FALSE
FALSE
The deepest muscle of the abdominal wall is the transversus abdominis.
TRUE/FALSE
TRUE
The deltoid muscle is a common site for intramuscular injections.
TRUE/FALSE
TRUE
Plantar flexion at the ankle joint is accomplished by the tibialis anterior muscle.
TRUE/FALSE
FALSE
Muscle development in babies occurs in a superior/inferior direction.
TRUE/FALSE
TRUE
Supination and pronation refer to up and down movements of the foot at the ankle.
TRUE/FALSE
FALSE
