Chapter 9 Muscles and Muscle Tissue Flashcards
An entire skeletal muscle is surrounded by __________.
A) perimysium
B) sarcolemma
C) epimysium
D) tendon sheath
E) endomysium
C) epimysium
A motor neuron along with all the muscle fibers it supplies is called a(n) __________.
A) synaptic cleft
B) motor unit
C) motor end plate
D) neuromuscular junction
E) axon terminal
- motor unit
Which of the following does NOT occur during skeletal muscle contraction?
A) Myosin heads bind to actin.
B) The I bands shorten, and H zones disappear.
C) Calcium binds to myosin heads.
D) Calcium concentration in the sarcoplasm increases.
E) ATP is hydrolyzed.
C) Calcium binds to myosin heads.
What is the ion released from the terminal cisternae that combines with troponin and removes the blocking action of tropomyosin, resulting in the formation of cross bridges?
- Na+
- Cl-
- K+
- H+
- Ca2+
- Ca2+
Each skeletal muscle fiber is controlled by a neuron at a single __________.
- neuromuscular junction
- sarcomere
- transverse tubule
- synaptic knob
- varicosity
- neuromuscular junction
Which of the following best describes the composition of the structure known as a triad in a skeletal muscle fiber?
- terminal cisterna, transverse tubule, and terminal cisterna
- ATP, CP, and glycogen
- actin, troponin, and tropomyosin
- sarcolemma, sarcoplasm, and sarcoplasmic reticulum
- A band, I band, and H band
- terminal cisterna, transverse tubule, and terminal cisterna
In the sliding filament model of muscle contraction, the myofilaments slide over each other, resulting in the overlapping of actin and __________.
- tropomyosin
- myosin
- troponin
- actin
- thin filaments
- myosin
Myoglobin __________.
- is a byproduct of glycolysis
- is a sugar-storage molecule
- activates myosin kinase in smooth muscle contraction
- is released into the sarcoplasm by the sarcoplasmic reticulum
- is an oxygen-storage molecule
- is an oxygen-storage molecule
The functional unit of contraction in a skeletal muscle fiber is the __________.
A) myofilament
B) sarcoplasmic reticulum
C) myofibril
D) sarcomere
E) sarcolemma
D) sarcomere
The space between the axon terminus of the neuron and the sarcolemma of the muscle fiber is the __________.
- synaptic knob
- M line
- synaptic cleft
- motor unit
- motor end plate
- synaptic cleft
Continued mild or partial contraction of a muscle that keeps it healthy and ready to respond is known as muscle __________.
- twitch
- stimulation
- tone
- tetanus
- summation
- tone
The type of muscle contraction in which the muscle fibers produce increased tension although the muscle neither shortens nor lengthens is called __________.
- isometric
- tetany
- treppe
- isotonic
- concentric
- isometric
Which of the following statements about smooth muscle is true?
- Contractions are rapid and forceful.
- Fibers are small and spindle-shaped.
- It has branching fibers.
- Nuclei are peripherally located in the fibers.
- Smooth muscle is striated and involuntary.
- Fibers are small and spindle-shaped.
Which of the following statements is INCORRECT?
- Smooth muscles form valves regulating the passage of substances through internal openings of the digestive and urinary tracts.
- The contractions of skeletal muscles pull on tendons and move elements of the skeleton.
- Skeletal muscle contractions help maintain body temperature.
- Skeletal muscles are responsible for the pumping action of the heart.
- Skeletal muscles support the weight of some internal organs.
- Skeletal muscles are responsible for the pumping action of the heart.
Which of the following substances increases in quantity during repetitive muscle contraction during oxygen deficit?
- oxygen
- creatine phosphate
- lactic acid
- adenosine triphosphate (ATP)
- glucose
- lactic acid
The sequence of electrical changes that occurs along the sarcolemma when a muscle fiber is stimulated is known as the __________.
A) receptor potential
B) action potential
C) generator potential
D) motor end plate potential
E) resting membrane potential
B) action potential
Which of the following allows recoil of the muscle fiber when contraction ends?
- troponin
- actin
- myosin
- tropomyosin
- elastic filaments
- elastic filaments
Which one of the following binds calcium ions in a smooth muscle, causing contraction?
- myosin
- troponin
- tropomyosin
- actin
- calmodulin
- calmodulin
All of the following terms refer to the ability to receive and respond to a stimulus EXCEPT __________.
- irritability
- excitability
- contractility
- responsiveness
- contractility
During the phase of excitation-contraction coupling of skeletal muscle, what occurs immediately after the action potential spreads down the T tubule?
- The cross bridge forms.
- The power stroke takes place.
- Acetylcholine is released from the axon terminus.
- The sarcoplasmic reticulum releases calcium.
4. The sarcoplasmic reticulum releases calcium.
Which of the following muscles is voluntary?
- the muscle of the stomach
- the muscle in the wall of the heart
- the muscle in the wall of the urinary bladder
- the muscle that extends the arm at the elbow
- the muscle that extends the arm at the elbow
Which of the following is NOT a characteristic of skeletal muscle contraction?
- It can perform both anaerobic and aerobic metabolism.
- It contracts rapidly.
- It can exert tremendous power.
- It can contract for long periods of time without tiring.
- It can contract for long periods of time without tiring.
Which type of skeletal muscle contains abundant quantities of glycogen?
- fast glycolytic fibers
- slow oxidative fibers
- slow glycolytic fibers
- fast oxidative fibers
- fast glycolytic fibers
Myofilament cross bridges form when which two structures bond?
- myosin tails and myosin heads
- troponin and tropomyosin
- globular actin and troponin
- myosin heads and globular actin
- myosin heads and globular actin
Which of the following is thought to be an autoimmune disease of acetylcholine receptors?
- muscular dystrophy
- myotonic dystrophy
- fibromyalgia
- myasthenia gravis
- myasthenia gravis
The refractory period in which the muscle will NOT contract if stimulated occurs during __________ of the muscle cell.
- hyperpolarization
- repolarization
- depolarization
- polarization
- repolarization
What is the cause of rigor mortis?
A) high levels of sodium in the cell after death
B) calcium influx into the sarcoplasm after death
C) breakdown of protein in the cell after death
D) diffusion of potassium out of the cell after death
B) calcium influx into the sarcoplasm after death
Where does 95% of the energy needed for contraction come from during moderate exercise?
- creatine phosphate
- aerobic respiration
- anaerobic glycolysis
- lactic acid
- aerobic respiration
The alternating contraction and relaxation of opposing layers of smooth muscle is referred to as __________.
- isometric contraction
- automatic contraction
- isotonic contraction
- peristalsis
- peristalsis
Which of the following characteristics is unique to smooth muscle?
- the absence of striations
- presence of gap junctions
- the ability of ATP to energize the sliding process
- presence of sarcoplasmic reticulum
- the absence of striations
A Bands are made of
A. myosin filaments only
B. actin filaments and Z discs
C. actin filaments only
D. myosin filaments and actin filaments
E. myosin filaments and Z discs
D. myosin filaments and actin filaments
What is the connective tissue surrounding an entire muscle cell called?
A. endomysium
B. perimysium
C. tendon
D. sarcolemma
E. epimysium
B. perimysium
The ___ ions released from the sarcoplasmic reticulum binds to sites on ________ causing a shift in that complex to expose myosin binding sites on the actin filaments.
A. Ca+2 ; troponin
B. Na+ ; tropomyosin
C. K+ ; troponin
D. Ca+2 ; tropomyosin
E. Ca+2 ; connectin
A. Ca+2 ; troponin
The H zone gets larger when a muscle is _______________.
A. contracted
B. resting
C. stretched
C. stretched
This enzyme allows for the conversion of two molecules of ADP to produce one molecule of ATP and one molecule of AMP for short term energy needs.
A. ATP synthase
B. creatine phosphatase
C. myokinase
D. ATPase
E. phosphagenase
C. myokinase
These structures are where smooth muscle intermediate filaments interact with sarcoplasm:
A. dense plaques
B. intermediate filament
C. T- tubules
D. dense bodies
E. myosin filament
D. dense bodies
Because of structure differences, smooth muscle is _______ to fatigue because it requires ______ ATP than skeletal muscle for contraction.
A. quicker; more
B. quicker; less
C. slower; more
D. slower; less
D. slower; less
Cardiac muscle cells are different from skeletal muscle cells in that they are ______, and contain ______ nuclei.
A. smooth; many
B. branched; 2
C. striated; 1
D. smooth; 2
E. branched; 1
B. branched; 2
Which mechanism provides ATP for short-term (5-10 sec) muscle contraction?
A. phosphagen system
B. aerobic respiration
C. anaerobic respiration
D. any of these
A. phosphagen system
1) 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
2) The A band within a skeletal muscle fiber is indicated by ________.
A) Label A
B) Label B
C) Label C
D) Label D
A) Label A
3) 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
4) The myofilament composed of actin is indicated by ________.
A) Label A
B) Label B
C) Label C
D) Label D
C) Label C
5) The epimysium is represented by ________.
A) Label A
B) Label B
C) Label C
D) Label D
A) Label A
6) 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
7) The muscle fiber (cell) is indicated by ________.
A) Label A
B) Label B
C) Label C
D) Label D
D) Label D
8) The endomysium that wraps individual muscle fibers is indicated by ________.
A) Label A
B) Label B
C) Label C
D) Label D
B) Label B
9) Striated involuntary muscle tissue is classified as ________ muscle.
A) skeletal
B) cardiac
C) smooth
D) either smooth or skeletal
B) cardiac
10) The epimysium covering on the outside of the muscle can blend into cordlike ________ or sheetlike ________.
A) tendons; aponeuroses
B) ligaments; tendons
C) fascia; ligaments
D) aponeuroses; ligaments
A) tendons; aponeuroses
The ________ is an organelle that wraps and surrounds the myofibril and stores calcium.
A) cross bridge
B) sarcomere
C) sarcolemma
D) sarcoplasmic reticulum
D) sarcoplasmic reticulum
12) Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________.
A) elasticity
B) irritability
C) contractility
D) extensibility
C) contractility
13) 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
15) The gap between the motor neuron and the muscle fiber it supplies at the neuromuscular junction is called the ________.
A) synaptic cleft
B) motor unit
C) cross bridge
D) H zone
A) synaptic cleft
16) When a skeletal muscle is fully contracted, the ________ are closer to the thick filaments.
A) Z discs
B) M lines
C) cross bridges
D) A bands
A) Z discs
17) Anaerobic glycolysis requires ________ to make ATP.
A) creatine phosphate
B) oxygen
C) glucose
D) both oxygen and glucose
B) oxygen
18) A smooth, sustained contraction is called ________.
A) fused, or complete, tetanus
B) a twitch
C) unfused, or incomplete, tetanus
D) summing of contractions
A) fused, or complete, tetanus
19) Contractions in which muscles shorten and produce movement are known as ________.
A) isotonic contractions
B) twitches
C) isometric contractions
D) resistance exercises
C) isometric contractions
20) 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
21) Muscles that perform opposite actions to one another are termed ________.
A) synergists
B) prime movers
C) antagonists
D) fixators
C) antagonists
22) The arrangement of fascicles in orbicularis oris is ________.
A) circular
B) convergent
C) pennate
D) fusiform
A) circular
23) The muscle that closes each eye is the ________.
A) orbicularis oris
B) frontalis
C) orbicularis oculi
D) zygomaticus
C) orbicularis oculi
24) The prime mover of arm abduction is the ________ muscle.
A) trapezius
B) deltoid
C) latissimus dorsi
D) quadratus lumborum
B) deltoid
25) The hamstring group is the prime mover of thigh ________ and knee ________.
A) extension; flexion
B) dorsiflexion; plantar flexion
C) abduction; adduction
D) rotation; circumduction
A) extension; flexion
26) 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
1) 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
2) Endomysium covers ________.
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
4) The plasma membrane of a skeletal muscle cell is called the ________.
A) sarcolemma
B) sarcomere
C) myofilament
D) sarcoplasm
E) sarcoplasmic reticulum
A) sarcolemma
5) Smooth muscle cells are ________.
A) multinucleate
B) involuntary
C) branched
D) striated
E) cylindrical
B) involuntary
6) Which type of muscle tissue contracts most quickly upon stimulation?
A) skeletal
B) visceral
C) cardiac
D) smooth
E) tendons
A) skeletal
7) 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) hematopoiesis
E) hematopoiesis
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
9) Which one of the following is composed of myosin protein?
A) thick filaments
B) thin filaments
C) all myofilaments
D) Z discs
E) light bands
A) thick filaments
10) Cross bridges are created when myosin heads bind to ________.
A) thick filaments
B) sarcomeres
C) thin filaments
D) sarcoplasmic reticula
E) myosin filaments
C) thin filaments
11) A motor neuron and all of the skeletal muscle fibers it stimulates are termed a ________.
A) myofilament
B) synaptic cleft
C) motor unit
D) neuromuscular junction
E) neurotransmitter
C) motor unit
12) Why are calcium ions necessary for skeletal muscle contraction?
A) calcium increases the action potential transmitted along the sarcolemma
B) calcium releases the inhibition on Z discs
C) calcium triggers the binding of myosin to actin
D) calcium causes ATP binding to actin
E) calcium binds to regulatory proteins on the myosin filaments, changing both their shape and their position on the thick filaments
C) calcium triggers the binding of myosin to actin
13) The mechanical force of contraction is generated by ________.
A) shortening of the thick filaments
B) shortening of the thin filaments
C) a sliding of thin filaments past thick filaments
D) the “accordian-like” folding of thin and thick filaments
E) the temporary disappearance of thin filaments
C) a sliding of thin filaments past thick filaments
14) Acetylcholine is ________.
A) an ion pump on the postsynaptic membrane
B) a source of energy for muscle contraction
C) a component of thick myofilaments
D) an oxygen-binding protein
E) a neurotransmitter that stimulates skeletal muscle
E) a neurotransmitter that stimulates skeletal muscle
15) 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
16) Neurotransmitters are released upon stimulation from a nerve impulse by 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
17) An elaborate and specialized network of membranes in skeletal muscle cells that function in calcium storage is the ________.
A) sarcolemma
B) mitochondria
C) intermediate filament network
D) myofibrillar network
E) sarcoplasmic reticulum
E) sarcoplasmic reticulum
18) During skeletal muscle contraction, myosin heads attach to binding sites associated with ________.
A) myosin filaments
B) actin filaments
C) Z discs
D) thick filaments
E) the H zone
B) actin filaments
Which of the following can actually shorten during a muscle contraction?
A) myosin filament
B) A band
C) actin filament
D) sarcomere
E) myofilament
D) sarcomere
20) In order to excite a muscle cell, acetycholine must ________.
A) enter the muscle cell by endocytosis
B) travel into the axon terminal of the nerve cell by endocytosis
C) enter the muscle cell through protein channels
D) bind to receptors in the sarcolemma of the muscle cell
E) break down acetylcholinesterase in the synaptic cleft
D) bind to receptors in the sarcolemma of the muscle cell
21) 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) causes temporary permeability to sodium
C) diffusion of potassium ions out of the cell
D) operation of the sodium-potassium pump
E) acetylcholinesterase (AchE) breaks down acetylcholine (ACh)
B) acetylcholine (ACh) causes temporary permeability to sodium
22) 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
23) 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
24) 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) insufficient intracellular quantities of ATP due to excessive consumption
D) a total lack of ATP
E) inadequate numbers of mitochondria
C) insufficient intracellular quantities of ATP due to excessive consumption
25) Which of the following is an example of an isometric contraction?
A) shaking the head as to say “no”
B) pushing against an immovable wall
C) bending the elbow
D) rotating the arm
E) nodding the head as to say “yes”
B) pushing against an immovable wall
26) Anaerobic glycolysis occurs without ________.
A) ATP
B) oxygen
C) lactic acid
D) carbon dioxide
E) glucose
B) oxygen
27) The least movable point of muscle attachment to a bone is termed its ________.
A) bone marking
B) function
C) insertion
D) action
E) origin
E) origin
28) The movement opposite to abduction is ________.
A) flexion
B) rotation
C) circumduction
D) adduction
E) supination
D) adduction
29) Which of the following muscles closes the jaw?
A) buccinator
B) zygomaticus
C) frontalis
D) sternocleidomastoid
E) both masseter and temporalis
E) both masseter and temporalis
30) 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
31) Which of these muscles is a synergist to masseter?
A) sternocleidomastoid
B) temporalis
C) trapezius
D) buccinator
E) orbicularis oris
B) temporalis
32) Which muscle helps compress the abdominal contents during defecation or childbirth?
A) internal intercostals
B) deltoids
C) trapezius
D) iliopsoas
E) rectus abdominis
E) rectus abdominis
33) A muscle located on the ventral (anterior) side of the body is the ________.
A) pectoralis major
B) occipitalis
C) gastrocnemius
D) gluteus medius
E) latissimus dorsi
A) pectoralis major
34) 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
35) 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
36) A muscle group that works with and assists the action of a prime mover is a(n) ________.
A) antagonist only
B) fixator only
C) synergist only
D) antagonist and synergist
E) antagonist and fixator
C) synergist only
37) Which muscle is an antagonist to gastrocnemius?
A) sartorius
B) tibialis anterior
C) fibularis brevis
D) fibularis longus
E) soleus
B) tibialis anterior
38) 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
39) 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
40) Which one of the following muscles is involved in abduction of the arm at the shoulder joint?
A) deltoid
B) biceps brachii
C) triceps brachii
D) latissimus dorsi
E) pectoralis major
A) deltoid
41) What is the origin of the deltoid muscle?
A) proximal radius
B) proximal humerus
C) distal humerus
D) olecranon process of ulna
E) scapular spine and clavicle
E) scapular spine and clavicle
42) 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
43) Which of the following muscles are antagonists?
A) biceps brachii and triceps brachii
B) bicpes femoris and biceps brachii
C) vastus medialis and vastus lateralis
D) masseter and temporalis
E) gastrocnemius and soleus
A) biceps brachii and triceps brachii
44) What condition results if muscles are not used, such as when immobilized in a cast for healing a broken bone?
A) hypertrophy
B) lordosis
C) atrophy
D) spina bifida
E) scoliosis
C) atrophy
45) 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
1) Cardiac and skeletal muscle both possess striations. True/False Questions
TRUE
2) All types of muscle have endomysium covering individual muscle cells. True/False Questions
TRUE
3) Bundles of muscle fibers are known as aponeuroses. True/False Questions
FALSE
4) The striations seen in skeletal muscle are actually alternating dark A and light I bands. True/False Questions
TRUE
5) The sarcoplasmic reticulum wraps like a sleeve around the myofibril and stores and releases calcium.True/False Questions
TRUE
6) A neuromuscular junction consists of one neuron and all the skeletal muscles it stimulates. True/False Questions
FALSE
7) The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine. True/False Questions
TRUE
8) Thick filaments are made of a protein called actin. True/False Questions
FALSE
9) Aerobic respiration requires the use of oxygen to generate ATP. True/False Questions
TRUE
10) The fastest mechanism for producing ATP is aerobic respiration. True/False Questions
FALSE
11) Isometric contractions produce movement when filaments slide past one another and the muscle shortens. True/False
FALSE
12) Aerobic, or endurance, exercise involves jogging or biking. True/False
TRUE
13) A muscle twitch results when the muscle is stimulated so rapidly that no evidence of relaxation is seen. True/False
FALSE
14) The effect of the neurotransmitter on the muscle cell membrane is to temporarily modify its permeability of ions such as Na+ and K+. True/False
TRUE
15) When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A bands move closer together but do not diminish in length. True/False
TRUE
16) Abduction and adduction are antagonistic actions. True/False
TRUE
17) The deltoid is a prime mover of arm adduction. True/False
FALSE
18) The deepest muscle of the abdominal wall is the transversus abdominis. True/False
TRUE
19) The deltoid muscle is a common site for intramuscular injections. True/False
TRUE
20) Plantar flexion at the ankle joint is accomplished by the tibialis anterior muscle. True/False
FALSE
21) The hamstring group inserts into the distal tibia. True/False
FALSE
22) Muscle development in babies occurs in a cephalic/caudal direction. True/False
TRUE
23) Supination and pronation refer to up and down movements of the foot at the ankle. True/False
FALSE
1) Voluntary muscle tissue
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
B) skeletal muscle tissue
2) Muscle tissue found only in the heart
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
C) cardiac muscle tissue
3) Muscle tissue that forms valves to regulate the passage of substances through internal body openings
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
A) smooth muscle tissue
4) Muscle tissue that is multinucleate
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
B) skeletal muscle tissue
5) Muscle tissue composed of branching cells and intercalated discs
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
C) cardiac muscle tissue
6) Muscle tissue that activates arrector pili muscles to stand hairs on end
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
A) smooth muscle tissue
7) Performs very slow, sometimes rhythmic, contractions
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
A) smooth muscle tissue
8) Muscle tissue that maintains posture, body position, and stabilizes joints
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
B) skeletal muscle tissue
9) The sarcoplasmic reticulum stores this chemical
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
A) calcium ions
10) Specific neurotransmitter that stimulates skeletal muscle cells
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
B) acetylcholine
11) Chemical that enters a muscle cell upon excitation
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
D) sodium ions
12) Gap between the axon terminals and the plasma membrane of a neighboring muscle cell
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
C) synaptic cleft
13) Electrical current that travels the length of the muscle
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
F) action potential
14) Enzyme that breaks down acetylcholine (ACh)
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
E) acetylcholinesterase
Muscle Tissue Type: ____________
- Long, cylindrical, ________ cells with obvious striations
- _______ and controls voluntary muscles movement
Skeletal; multinucleate; Initiates
Muscle Tissue Type: _______
- Branching, ______, single nucleate cells connected at intercalated discs
- Found in the _____ of the heart
- Under involuntary control
Cardiac; striated; walls
Muscle Tissue Type: ______
- Sheets of spindle-shaped cells with single nuclei that have no ______
- Found in the walls of ______, some ducts and hollow organs
- Under involuntary control
Smooth; striations; blood vessels
Which of the following muscular functions serves a metabolic function?
A) Movement
B) Posture maintenance
C) Joint stabilization
D) Heat generation
D) Heat generation
Which of the following pairs is not correct?
A) Skeletal muscle : striated
B) Cardiac muscle : voluntary
C) Cardiac muscle : striated
D) Smooth muscle : involuntary
B) Cardiac muscle : voluntary
Of the following muscle types, which is the only one subject to conscious control?
A) Smooth
B) Skeletal
C) Cardiac
D) All of these muscle types are subject to conscious control.
B) Skeletal
Which of the following is not a functional characteristic of muscle tissue?
A) Excitability/irritability
B) Contractility
C) Extensibility
D) Elasticity
E) All are functional characteristics of muscle tissue
E) All are functional characteristics of muscle tissue
Elasticity is the ability to shorten in length when stimulated. True/False
FALSE, Contractility
Extensibility is the bility to be stretched or extended beyond their resting length without rupturing. True/False
True
Myofibril are thin muscle structures. True/False
TRUE
Each muscle is a discrete organ composed of hundreds to thousands of muscle fibers, blood vessels, nerve fibers, and connective tissue. True/False
TRUE
Which of the following is not true of Skeletal Muscle Tissue?
A) Has a rich blood supply due to its high metabolic demands
B) Contains obvious bands/striations under the microscope
C) Under Both voluntary and involuntary control.
D) Under voluntarily control
E) Contracts rapidly but tires easily
C) Under Both voluntary and involuntary control.
Each muscle is divided into smaller sections called muscle fiber. True/False
FALSE, they are call fasicles
What is it called?
Endomysium
(between individual muscle fibers)
What is it?
Fascicle
(Wrapped by perimysium)
The epimysium may be ________ fused to the periosteum or the perichondrium of cartilage.
A) directly
B) indirectly
A) directly
The epimysium may attach ________ via tendons that extend beyond the muscle, or as broad, sheet-like aponeuroses.
A) directly
B) indirectly
B) indirectly
Indirect attachments are more common than the direct attachment. True/False
TRUE
Most skeletal muscles span joints and are attached to bone in at least _______ places.
two
One end is relatively immobile, while the other end moves the bone. The Origin is the movable end of the skeletal muscle. True/False
FALSE, the movable end is the insertion
Which of the following is not a prefix used to refer to muscle?
A) Mys
B) Myo
C) Sarco
D) Lemma
D) Lemma
The elastic components of muscle consist of which elements?
A) Tendon, epimysium, muscle fiber
B) Bone, perimysium, blood vessel
C) Fascicle, bone, blood vessel
D) Tendon, epimysium, perimysium, endomysium
D) Tendon, epimysium, perimysium, endomysium
Sarcoplasm contains a unique oxygen-binding protein called _______ .
myoglobin
Myoglobin is a protein found in the muscle tissue of vertebrates in general and in almost all mammals. True/False
TRUE
Hemoglobin is the primary oxygen-carrying pigment of muscle tissues. True/False
FALSE, myoglobin is the primary oxygen-carrying pigment of muscle tissues.
Myofibrils are densely packed, rod-like contractile elements within a muscle fiber. True/Flase
TRUE
The myofibrils within a fiber are aligned into a repeating series of striations or stripes called Sarcolemma. True/False
FALSE, they are called sarcomeres
What is the functional, contractile unit of a muscle?
A) myosin
B) sarcomere
C) bactin
D) myofibril
B) sarcomere
Actin and myosin are the primary proteins responsible for muscle contraction. True/False
TRUE
Proteins (connections) that anchor the thin actin filaments.
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
D) Z-disc
Extends to the right and left of a Z disk and includes the non-overlapping parts of the thin filaments
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
A) I(light) band
Extends the length of the thick myosin filament
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
E) A(dark) band
In the center of the A band, includes the portion of the thick filament NOT overlapping with the thin filament
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
B) H zone
Middle of H zone that contains delicate fibers holding the thick filaments in place
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
C) M line
In the relaxed state, thin (actin) and thick myosin) filaments overlap _____.
A) completely
B) slightly
B) slightly
By the end of contraction, actin and myosin filaments overlap ______.
A) completely
B) slightly
A) completely
§Thick filaments are composed of the protein _____, held together by the protein____.
Myosin; Titin
Which of the following components accounts for the bulk of muscle fiber volume?
A) Glycosomes
B) Mitochondria
C) Myofibrils
D) Sarcoplasm
C) Myofibrils
The functional unit of a skeletal muscle is:
A) sarcomere
B) A band
C) myofibril
D) sarcolemma
A) sarcomere
A sheetlike extension of the epimysium is called a(n) ______
A) aponeurosis
B) fascicle
C) sarcoplasmic reticulum
D) tendon
A) aponeurosis
Thick filaments are found in the _______ of the sarcomere.
A) Z disc
B) I band
C) A band
D) All of the above contain thick filaments.
C) A band
The thin filaments are not comprised of which of the following components?
A) Actin
B) Titin
C) Troponin
D) Tropomyosin
B) Titin
In a resting muscle cell, the myosin-binding sites are blocked by ______.
A) actin
B) troponin
C) titin
D) tropomyosin
D) tropomyosin
Which of the following statements is incorrect?
A) The plasma membrane of a muscle cell is called sarcolemma
B) The T tubules are invaginations of the sarcolemma
C) The cytoplasm of a muscle is called sarcoplasm
D) There is cell to cell continuity between a nerve and a muscle fiber at the neuromuscular junction
D) There is cell to cell continuity between a nerve and a muscle fiber at the neuromuscular junction
What causes action and myosin filaments to bind to each other?
A) the entry of calcium ions into the the nerve terminal
B) the release of acetylcholine into the synaptic cleft
C) the entry of Na ions into the sarcoplasm
D) the binding of Ca ions to actin filaments to expose the active sites
D) the binding of Ca ions to actin filaments to expose the active sites
The first source used to generate ATP when muscles are extremely active is
A) Body fat
B) Aerobic respiration
C) Anaerobic glycolysis
D) Creatine phosphate
D) Creatine phosphate
Muscle tone is ________.
A) the ability of a muscle to relax following contraction
B) the feeling of well-being following exercise
C) a state of sustained partial contraction
D) the condition of athletes after intensive training
C) a state of sustained partial contraction
Creatine phosphate functions in the muscle cell by ________.
A) forming a temporary chemical bond with myosin
B) forming a chemical bondwith actin
C) inducing a change in shape of the myofilaments
D) storing energy that will be transferred to ADP to resynthesize ATP
D) storing energy that will be transferred to ADP to resynthesize ATP
What is the functional role of the T tubules?
A) stabilize actin
B) enhance cellular communication during muscle contraction
C) hold cross bridges in place in a resting muscle
D) synthesize ATP to provide energy for muscle contraction
B) enhance cellular communication during muscle contraction
What produces the striations of a skeletal muscle cell?
A) a difference in the thickness of the sarcolemma
B) the arrangement of myofilaments
C) the sarcoplasmic reticulum
D) the T tubules
B) the arrangement of myofilaments
What is resting membrane potential ?
A) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is more positively charged compared to the outside
B) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is less positively charged compared to the outside
C) The action potential that travels across the sarcolemma when a muscle is resting.
D) None of the above
B) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is less positively charged compared to the outside
An untrained person, trying to run a marathon, becomes fatigued because of an oxygen debt, and a build up of lactic acid in the body.
True
False
True
- ______ surrounds bundles of fibers
- ______ surrounds each individual fiber
- ______ surrounds the entire muscle
- Perimysium
- endomysium
- epimysium
Which of the following muscle types is/are both voluntary and striated?
A) skeletal muscle only
B) cardiac muscle and skeletal muscle
C) cardiac muscle only
D) smooth muscle only
A) skeletal muscle only
Muscle cells initiate nerve impulses.
True
False
False
Neurons are responsible for initiating nerve impulses.
The final “go” signal for skeletal muscle contraction is __________.
A) an increase in extracellular calcium ion levels
B) a decrease in extracellular calcium ion levels
C) a decrease in intracellular calcium ion levels
D) an increase in intracellular calcium ion levels
D) an increase in intracellular calcium ion levels
The __________ are inward invaginations of the sarcolemma that run deep into the cell and ensure that every myofibril in the muscle fiber contracts at virtually the same time.
A) Z discs
B) T tubules
C) A bands
D) thin filaments
B) T tubules
The thin myofilaments of skeletal muscle are composed chiefly of __________.
A) myosin
B) actin
C) tropomyosin
D) troponin
B) actin
Acetylcholinesterase __________.
A) helps acetylcholine bind to its receptor
B) is another name for acetylcholine
C) activates acetylcholine
D) breaks down acetylcholine
D) breaks down acetylcholine
Myofibrils are composed of repeating contractile elements called __________.
A) actin
B) sarcomeres
C) myofilaments
D) myosin
B) sarcomeres
Which of the following statements is FALSE?
A) During contraction, thin filaments slide past thick filaments so that actin and myosin filaments do not overlap.
B) During contraction, the distance between Z discs of a sarcomere decreases.
C) During contraction, thin filaments slide past thick filaments so that actin and myosin filaments overlap.
D) During contraction, actin-myosin cross bridges form.
A) During contraction, thin filaments slide past thick filaments so that actin and myosin filaments do not overlap.
When an action potential arrives at the neuromuscular junction, the most immediate result is __________.
A) a rise in intracellular Ca2+ levels in the muscle fiber
B) the formation of actin-myosin cross bridges
C) the release of acetylcholine from the motor neuron
D) the depolarization of the sarcolemma
C) the release of acetylcholine from the motor neuron
If a muscle is applied to a load that exceeds the muscle’s maximum tension, __________.
A) the load will be moved by the contraction
B) the contraction is isotonic
C) the muscle length will not change during contraction
D) the muscle length will shorten during contraction
C) the muscle length will not change during contraction
Properly controlled skeletal muscle contractions produced by changing the frequency of stimulation and the strength of stimulation are referred to as __________.
A) muscle twitches
B) multiple motor unit summation
C) graded muscle responses
D) wave summation
C) graded muscle responses
The most efficient means of producing ATP for muscle contraction is __________.
A) anaerobic glycolysis
B) aerobic respiration
C) anaerobic respiration
D) lactic acid formation
B) aerobic respiration
What would occur if a contracting muscle became totally depleted of ATP?
A) The muscle would remain in a contracted state because of an inability to break actin-myosin cross bridges.
B) The muscle would exhibit isometric contraction.
C) The muscle would exhibit isotonic contraction.
D) The muscle would relax and lengthen because of an inability to sustain actin-myosin cross bridges.
A) The muscle would remain in a contracted state because of an inability to break actin-myosin cross bridges.
Match the muscle fiber to the appropriate characteristic: fast oxidative muscle fiber
A) fatigue resistant
B) moderately fatigue resistant
C) fatigues quickly
B) moderately fatigue resistant
Match the muscle fiber to the appropriate characteristic: fast glycolytic fiber
A) fatigue resistant
B) moderately fatigue resistant
C) fatigues quickly
C) fatigues quickly
Match the muscle fiber to the appropriate characteristic: slow oxidative muscle fiber
A) fatigue resistant
B) moderately fatigue resistant
C) fatigues quickly
A) fatigue resistant
Which of the following is FALSE regarding smooth muscle?
A) Contraction of smooth muscle is regulated by the autonomic nervous system.
B) Once damaged, smooth muscle is unable to regenerate.
C) Smooth muscle tends to be organized in sheets.
D) Smooth muscle is not striated.
B) Once damaged, smooth muscle is unable to regenerate.
Choose the true statement.
A) Unlike skeletal muscle, contraction in smooth muscle does not involve a sliding filament mechanism.
B) The final signal for contraction in smooth muscle is a rise in extracellular calcium, while the final signal for contraction in skeletal muscle is a rise in intracellular calcium.
C) Smooth muscle depends on the calcium-calmodulin system to regulate contraction, while skeletal muscle relies on the calcium-troponin system to regulate contraction.
D) Unlike skeletal muscle, smooth muscle does not depend on ATP to fuel contractions.
C) Smooth muscle depends on the calcium-calmodulin system to regulate contraction, while skeletal muscle relies on the calcium-troponin system to regulate contraction.
Duchenne muscular dystrophy is more common in females than in males.
True
False
False
Which structure in the figure corresponds to a single skeletal muscle cell?
A
B
C
D
C
Labels the following: I band
Label the following: Sarcolemma
Which of the following statements is incorrect?
A) The plasma membrane of a muscle cell is called sarcolemma
B) The T tubules are invaginations of the sarcolemma
C) The cytoplasm of a muscle is called sarcoplasm
D) There is cell to cell continuity between a nerve and a muscle fiber at the neuromuscular junction
D) There is cell to cell continuity between a nerve and a muscle fiber at the neuromuscular junction
What causes action and myosin filaments to bind to each other?
A) the entry of calcium ions into the the nerve terminal
B) the release of acetylcholine into the synaptic cleft
C) the entry of Na ions into the sarcoplasm
D) the binding of Ca ions to actin filaments to expose the active sites
D) the binding of Ca ions to actin filaments to expose the active sites
Which structure is filled with the neurotransmitter?
Synaptic Cleft
The first source used to generate ATP when muscles are extremely active is
A) Body fat
B) Aerobic respiration
C) Anaerobic glycolysis
D) Creatine phosphate
D) Creatine phosphate
Muscle tone is ________.
A) the ability of a muscle to relax following contraction
B) the feeling of well-being following exercise
C) a state of sustained partial contraction
D) the condition of athletes after intensive training
C) a state of sustained partial contraction
Creatine phosphate functions in the muscle cell by ________.
A) forming a temporary chemical bond with myosin
B) forming a chemical bondwith actin
C) inducing a change in shape of the myofilaments
D) storing energy that will be transferred to ADP to resynthesize ATP
D) storing energy that will be transferred to ADP to resynthesize ATP
What is the functional role of the T tubules?
A) stabilize actin
B) enhance cellular communication during muscle contraction
C) hold cross bridges in place in a resting muscle
D) synthesize ATP to provide energy for muscle contraction
B) enhance cellular communication during muscle contraction
What produces the striations of a skeletal muscle cell?
A) a difference in the thickness of the sarcolemma
B) the arrangement of myofilaments
C) the sarcoplasmic reticulum
D) the T tubules
B) the arrangement of myofilaments
What is resting membrane potential ?
A) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is more positively charged compared to the outside
B) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is less positively charged compared to the outside
C) The action potential that travels across the sarcolemma when a muscle is resting.
D) None of the above
B) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is less positively charged compared to the outside
An untrained person, trying to run a marathon, becomes fatigued because of an oxygen debt, and a build up of lactic acid in the body.
True
False
True
Isotonic contraction _______ muscle length.
A) decreases
B) increases
A) decreases
Muscles shorten during contraction
Isometric contraction __________ muscle tension.
A) decreases
B) increases
B) increases
During Isometric contraction muscle _______ during contraction.
A) shortens
B) does not shorten
B) does not shorten
The muscle may “bulge” and individual fibers may shorten but the muscle does not shorten
The first few milliseconds after stimulation before contraction begins.
A) relaxation period
B) Latent period
C) period of contraction
B) Latent period
Cross bridges actively form and the muscle shortens.
A) relaxation period
B) Latent period
C) period of contraction
C) period of contraction
Ca2+ reenters the SR, and muscle tension returns to zero.
A) relaxation period
B) Latent period
C) period of contraction
A) relaxation period
Calcium is released from the terminal cisterns in response to ______.
A) ATP
B) calcium pumps
C) an action potential
D) troponin
C) an action potential
Where is calcium (Ca2) stored?
A) terminal cisterns
B) T-tubules
C) mitochondria
D) sarcoplasmic reticulum
D) sarcoplasmic reticulum
What is the significance of the muscle fiber triad relationship?
A) The terminal cisterns subdivide the sarcolemma.
B) The T tubules bring calcium to the sarcoplasmic reticulum.
C) The sarcoplasmic reticulum transfers calcium to the T tubules.
D) The T tubules conduct electrical impulses that stimulate calcium release from the sarcoplasmic reticulum.
D) The T tubules conduct electrical impulses that stimulate calcium release from the sarcoplasmic reticulum.
In order to receive a signal to contract, each skeletal muscle must be served by a(n) ________.
A) artery
B) nerve
C) vein
D) ligament
B) nerve
At the neuromuscular junction, the muscle contraction initiation event is ______.
A) a release of calcium ions from the sarcoplasmic reticulum
B) conduction of an electrical impulse down the T tubules
C) binding of acetylcholine to membrane receptors on the sarcolemma
D) sliding of actin and myosin filaments past each other
C) binding of acetylcholine to membrane receptors on the sarcolemma
What would be the first response of a muscle fiber treated with an acetylcholinesterase inhibitor?
A) The muscle fiber would continue to contract in the absence of additional nervous system stimulation.
B) The muscle fiber would be nonresponsive to acetylcholine.
C) Acetylcholine would be retained in the axon terminal.
D) The muscle fiber would continuously contract for a prolonged period of time.
A) The muscle fiber would continue to contract in the absence of additional nervous system stimulation.
Corpses usually exhibit rigor mortis because ______.
A) ATP hydrolysis is stimulating myosin head attachment to actin
B) a lack of ATP hydrolysis prevents myosin head detachment from actin
C) calcium stores become deficient
D) sodium stores become deficient
B) a lack of ATP hydrolysis prevents myosin head detachment from actin
T tubules are an extension of the _________.
A) sarcomere
B) sarcoplasmic reticulum
C) sarcolemma
D) endomysium
C) sarcolemma
Calcium is released from the terminal cisterns in response to ______.
A) ATP
B) calcium pumps
C) an action potential
D) troponin
C) an action potential
In a muscle fiber, the key intracellular event that stimulates muscle contraction is known as ______.
A) polarization
B) depolarization
C) repolarization
D) potential
B) depolarization
During depolarization, the sarcolemma is most permeable to ______.
A) sodium ions
B) potassium ions
C) calcium ions
D) chloride ions
A) sodium ions
Activities that require a brief surge of power rely entirely on direct phosphorylation and ATP stores.
A) Tennis, 100 meter swiming, football
B) Weight lifting, sprinting
C) Marathon runners, jogging
B) Weight lifting, sprinting
Activities that require on-off surges of power for longer periods rely entirely on anaerobic glycolysis
A) Tennis, 100 meter swiming, football
B) Weight lifting, sprinting
C) Marathon runners, jogging
A) Tennis, 100 meter swiming, football
Activities that require prolonged endurance rely primarily on aerobic respiration
A) Tennis, 100 meter swiming, football
B) Weight lifting, sprinting
C) Marathon runners, jogging
C) Marathon runners, jogging
How much energy released in muscle activity is useful as work?
A) 60%
B) 40%
B) 40%
60% is given off as heat
Does not cause skeletal muscle hypertrophy.
A) resistance exercise
B) aerobic exercise
A) resistance exercise
Small precise movements are controlled by ______ motor units.
A) small
B) large
C) many
D) few
A) small
Isometric contractions come into play when an individual is ________.
A) jumping
B) walking uphill
C) moving a heavy object
D) maintaining an upright posture
D) maintaining an upright posture
A major cellular feature in smooth muscle that contributes to its rhythmicity and ability to participate in peristalsis is the presence of ______.
A) troponin complex
B) gap junctions
C) varicosities
D) caveolae
B) gap junctions
The principal neurotransmitter of skeletal muscle is acetylcholine. The major neurotransmitter(s) of smooth muscle is (are) _______.
A) acetylcholine
B) epinephrine
C) norepinephrine
D) all of the above
D) all of the above
What substance must bind to myosin heads in order for the heads to detach from the thin filaments?
A) Calcium
B) ATP
C) Troponin
D) Sodium
B) ATP
In a resting muscle cell, the myosin-binding sites are blocked by ______.
A) actin
B) troponin
C) titin
D) tropomyosin
D) tropomyosin
T-Tubules are an extension of the ____
A) sarcoplasmic reticulum
B) sarcomere
C) sarcolemma
D) tendon
C) sarcolemma
Which of the following best describes the events of “excitation” in “excitation-contraction coupling”?
A) propagation of the action potential along the sarcolemma
B) cross bridge formation
A) propagation of the action potential along the sarcolemma
Which of the following best describes the events of “contraction” in “excitation-contraction coupling”?
A) propagation of the action potential along the sarcolemma
B) cross bridge formation
B) cross bridge formation
The hydrolysis of the ATP that is bound to myosin causes:
A) Irreversible binding of myosin to the actin filament
B) Phosphorylation of the actin filament
C) Release of myosin head from the actin filament
D) Reversible binding of myosin to the actin filament
C) Release of myosin head from the actin filament
What is the role of tropomyosin in muscle contraction?
A) To aid in myosin ‘cocking’ on the actin filament
B) To release troponin from tropomyosin, allowing myosin to bind to the actin filament
C) To prevent myosin from continuing to slide up the actin filament
D) To release calcium from the sarcoplasmic reticulum
C) To prevent myosin from continuing to slide up the actin filament
What is the role of acetylcholine in calcium release?
A) Stimulates cellular contraction by opening voltage-gated ion channels
B) Stimulates postsynaptic acetylcholine receptors to release intracellular calcium
C) Binds to sarcoplasmic reticulum, causing calcium release
D) Binds to the sarcolemma, causing calcium release
A) Stimulates cellular contraction by opening voltage-gated ion channels
Which of the following correctly identifies muscle components in order from largest to smallest?
A) Fasciculus, muscle bundle, myofibril
B) Fasciculus, muscle fiber, myofibril
C) Sarcolemma, sarcoplasm, fasciculus
D) Muscle fiber, fasciculus, myofibril
B) Fasciculus, muscle fiber, myofibril
The space between two Z lines constitutes the:
A) Sarcolemma
B) Sarcoplasm
C) Sarcomere
D) Sarcophagus
C) Sarcomere
What is an aponeurosis?
A) An area of smooth muscle in the abdomen
B) A segment of muscle that is not attached to bone
C) A large, flat tendon that anchors muscle
D) A group of neurons that innervate striated muscle cells
C) A large, flat tendon that anchors muscle
We would expect to find smooth muscle in all of the following EXCEPT:
A) Esophagus
B) Myocardial tissue
C) Pulmonary circulatory tissue
D) Small intestine
B) Myocardial tissue
Curare is a naturally-occurring compound that competitively binds to nicotinic acetylcholine receptors on muscle cells. Which of the following symptoms might be seen in a patient who has been exposed to curare?
A) Muscle spasticity
B) Diaphragmatic paralysis
C) Excessive salivation
D) Cardiac arrest
B) Diaphragmatic paralysis
Which of the following is accurate regarding Type I and Type II muscle fibers?
A) Type I fibers are white, whereas Type II fibers are red
B) Type I fibers employ anaerobic metabolism, whereas Type II fibers utilize aerobic metabolism
C) Type I fibers store much of their energy as triglycerides, whereas Type II fibers store energy as ATP or creatine phosphate
D) Type I fibers are easily fatigued and are therefore intended for short bursts of activity
C) Type I fibers store much of their energy as triglycerides, whereas Type II fibers store energy as ATP or creatine phosphate
Which of the following is NOT innervated by the autonomic nervous system?
A) Intestinal muscle cell
B) Myocardial cell
C) Branching muscle cell
D) Striated muscle cell
D) Striated muscle cell
Binding of ACh to a nicotinic receptor on the motor end plate will cause the muscle cell membrane potential to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
During muscle contraction, the overlap between actin and myosin will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
During muscle contraction, the size of the A band will:
A) Increase
B) Decrease
C) Stay the same
C) Stay the same
During muscle relaxation, the size of the H zone will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
During muscle contraction, the width of the I band will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
In response to calcium release from the SR, the number of available myosin binding sites on actin will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
Binding of ACh to a nicotinic receptor on the motor end plate will cause the calcium levels in the sarcoplasmic reticulum to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
During muscle relaxation, the distance between adjacent Z discs will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
During sarcomere contraction, the size of the I band will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
During sarcomere contraction,the size of the A band will:
A) Increase
B) Decrease
C) Stay the same
C) Stay the same
During sarcomere contraction, the size of the H zone will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
In response to an action potential travelling down a t-tubule, the amount of calcium in the neighboring terminal cisterna will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
An increase in sarcoplasm calcium levels will cause the number of myosin-binding sites on actin that are blocked by tropomyosin to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
During muscle cell relaxation, the amount of overlap between the thin and thick filaments will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
Binding of nicotine to the receptor on the motor end plate will cause the membrane potential to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
A drug that blocked acetylcholinesterase would cause ACh levels in the synaptic cleft of a neuromuscular junction to:
A) Increase
B) Decrease
C) Stay the same
A) Increase
The arrival of an action potential that the axon terminal of a somatic motor neuron would cause the amount of ACh in the axon terminal to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
An increase in the number of motor units activated in a skeletal muscle will cause the tension generated by that skeletal muscle to:
A) Increase
B) Decrease
C) Stay the same
A) Increase
During an isotonic eccentric muscle contraction, tension is generated and maintained as muscle length:
A) Increase
B) Decrease
C) Stay the same
A) Increase
As a result of endurance training, the capillary density of a skeletal muscle will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
As a result of resistance training, the number of myofibrils per muscle fiber will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
As Brock sprints 100 meters, the amount of glycogen in the muscle fibers of his hamstrings will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
Which of the following is a characteristic of muscle cells?
A) Excitability
B) Contractility
C) Elasticity
D) Extensibility
E) All of the above
E) All of the above
If the muscle fiber was stimulated again at time=50ms, the tension generated in response would exceed the tension generated in the initial twitch.
True
False
True
At time=_______ms, the muscle cell is in its latent period.
A) 2
B) 18
C) 35
D) 120
E) 150
A) 2
At time=60ms, calcium is actively being pumped into the sarcoplasmic reticulum
True
False
True
Which of the following stabilizes the thick filaments in a myofibril?
A) Z disc
B) Z line
C) A band
D) M line
E) H zone
D) M line
Which of the following binds calcium during excitation-contraction coupling?
A) Tropomyosin
B) Actin
C) Myosin
D) Troponin
E) All of the above
D) Troponin
Which of the following must myosin bind in order to let go of actin?
A) Calcium
B) Troponin
C) ATP
D) ADP
E) Inorganic phosphate
C) ATP
A muscle fiber and all of the axon terminals that synapse with it are collectively referred to as a motor unit.
True
False
False
A motor unit consists of one motor neuron and all the muscle fibers it innervates
