Ch10 Flashcards
The different types of muscle tissue differ from each other by
Microscopic anatomy Location Type of control Both microscopic and location All of these
All of these
Which of the following is NOT a major function of muscle tissue?
Moving blood through the body Generating heat through contractions Stabilizing the movement of joints Promoting movement of body structures Production of vitamins
Production of vitamins
Which property of muscle gives it the ability to stretch without damage?
Electrical excitability Contractility Extensibility Elasticity Thermogenesis
Extensibility
In an isometric contraction the muscle develops but does not….
Lengthen Widen Does not expend energy Conduct electrical current Exhibit elasticity
Lengthen
This is the outermost layer of connective tissue surrounding the skeletal muscle
Tendon Ligament Endomysium Epimysium Perimysium
Epimnysium
What type of tendon is formed when connective tissue elements of skeletal muscle extend as a broad flat layer?
Perimysium Deep fascia Fascicle Aponeurosis Endomysium
Aponeurosis
After the fusion of myoblasts, the muscle fiber are thread-like structures called..
Myofibrils Myoglobin Mitochondria Z discs M lines
Myofibrils
Release of calcium from these structures triggers skeletal muscle contractions
Myofibrils Mitochondria Terminal cisterns of sarcoplasmic reticulum T-tubules None of these are correct
Terminal cisterns of sarcoplasmic reticulum
Which of the following regions of a sarcomere contain thin filaments?
I band A band H zone Both I band and A band All of these are correct
Both I band and A band
Which of the following regions of the sarcomere contain thick filaments?
A zone of overlap A band H zone Both A band and H zone All of these answer choices are correct
All of these answer choices are correct
Myofibrils contain
Contractile Regulatory proteins Structural proteins All of these None of these
All of these
Which of the following functions as a motor protein in all three types of muscle tissue?
Actin Myosin Troponin Titin Tropomyosin
Myosin
What regulatory proteins can be found in the thin filaments of skeletal muscle fibers?
Troponin and titin
Tropomyosin and troponin
Myosin and titin
Titin and tropomyosin
Tropomyosin and troponin
Which of the regions of a sarcomere contain titin?
The A band only The H zone only The zone of overlap only From M to Z disc The I band only
From M line to Z disc
19) Which of the following proteins is used to reinforce the sarcolemma and to help transmit the tension generated by the sarcomeres to the tendons?
a) troponin
b) tropomyosin
c) myosin
d) actin
e) dystrophin
dystrophin
20) During muscle contraction by the sliding filament mechanism, thin filaments are pulled towards the
a) Z disc.
b) H zone.
c) M line.
d) A band.
e) I band.
M line
21) Calcium ions are released from the sarcoplasmic reticulum into the cytosol
a) at the beginning of a contraction.
b) in response to acetylcholine binding to Ca2+ release channels.
c) by active transport using Ca2+ pumps in the SR membrane.
d) after the contraction ends.
e) All of these answers are correct.
a) at the beginning of a contraction
22) What energizes the myosin head?
a) the actin filaments
b) calcium ions
c) potassium ions
d) ATP hydrolysis reaction
e) ADP synthesis
d) ATP hydrolysis reaction
23) Skeletal muscle contraction will continue to occur as long as the following chemicals are available in the cytosol of the muscle fiber.
a) ATP and acetylcholine (ACh)
b) calcium ions and ATP
c) ACh and potassium ions
d) sodium ions and ATP
e) calcium and ACh
b) calcium ions and ATP
24) To stimulate skeletal muscle contraction, acetylcholine must cross the _____ of the neuromuscular junction and bind to receptors on the motor endplate.
a) node of Ranvier
b) synaptic cleft
c) sarcolemma
d) synaptic end bulb
e) transverse tubule
b) synaptic cleft
25) Which of the following are commonly used to produce ATP during skeletal muscle contraction?
a) creatine phosphate
b) anaerobic cellular respiration
c) aerobic cellular respiration
d) All of these choices are correct.
e) None of these choices are correct.
d) All of these choices are correct
26) In skeletal muscles, the combined amounts of creatine phosphate and ATP provide enough energy for the muscle to contract maximally for approximately
a) 15 seconds.
b) 15 minutes.
c) 1.5 minutes.
d) 5 seconds.
e) one minute.
15 seconds
28) Which of the following consists of a somatic motor neuron and all the skeletal muscle fibers it stimulates?
a) sarcomere
b) motor unit
c) neuromuscular junction
d) muscle unit
e) multi-unit smooth muscle
b) motor unit
29) A brief contraction of all muscle fibers in a motor unit in response to a single action potential moving down the somatic motor neuron is known as
a) isometric contraction.
b) isotonic contraction.
c) tetany.
d) refractory period.
e) twitch contraction.
e) twitch contraction
30) Which of the following is referred to as the period of lost excitability in skeletal muscle fibers?
a) refractory period
b) contraction period
c) latent period
d) relaxation period
e) wave summation
a) refractory period
31) Increasing the number of active motor units within a skeletal muscle is called
a) wave summation.
b) fused tetanus.
c) motor unit recruitment.
d) muscle tone.
e) flaccidity.
c) motor unit recruitment
This is the least powerful type of skeletal muscle fiber.
a) slow oxidative fiber
b) fast oxidative fiber
c) fast glycolytic fiber
d) slow glycolytic fiber
e) None of these choices.
a) slow oxidative fiber
Which of the following microscopic structures is only found in the cardiac muscle tissue?
a) myosin
b) tropomyosin
c) sarcomeres
d) intercalated discs
e) striations
d) intercalated discs
Which of the following types of muscle tissue contract when excited by their own autorhythmic muscle fibers?
a) cardiac muscle
b) slow twitch oxidative skeletal muscle
c) multi-unit smooth muscle
d) fast twitch glycolytic skeletal muscle
e) All of these choices are correct.
a) cardiac muscle
Smooth muscle tone is maintained by the prolonged presence of _____ in the muscle cell’s cytosol?
a) ATP
b) calcium ions
c) phosphate ions
d) myoglobin
e) None of these choices.
b) calcium ions
55) Which of the following disorders is characterized by the wasting away of muscles due to the progressive loss of myofibrils?
a) muscular hypertrophy
b) muscular atrophy
c) fibromyalgia
d) myasthenia gravis
e) tremors
b) muscular atrophy
Which is a NOT a side-effect of anabolic steroid use by male athletes?
a) sterility
b) baldness
c) diminished testosterone secretion
d) deepening of the voice
e) atrophy of testes
d) deepening of the voice
64) Which of the following types of abnormal contractions of skeletal muscle may be caused by holding a position for a prolonged period?
a) spasm
b) fasciculation
c) tremor
d) fibrillation
e) cramp
Cramp
Which of the following is a common effect of aging on skeletal muscle?
a) loss of muscle mass
b) decrease in maximal strength
c) a slowing of muscle reflexes
d) loss of flexibility
e) all of these are correct
e) all of these are correct
Which of the following statements does NOT accurately describe aerobic cellular respiration in skeletal muscles?
a) Pyruvic acid generated by glycolysis enters the mitochondria.
b) O2 is essential.
c) CO2 is produced as a waste product.
d) Lactic acid is continually produced.
e) Can be used to generate ATP from fats, proteins or carbohydrates.
d) Lactic acid is continually produced
After prolonged strenuous exercise has stopped, heavy breathing will often continue for several minutes in order to provide the oxygen needed to
a) convert the lactic acid produced during exercise back into glycogen.
b) resynthesize creatine phosphate.
c) replace oxygen displaced from muscle myoglobin.
d) All of these choices
e) None of these choices
All of these
Which of the following types of muscle tissue is capable of undergoing the stress-relaxation response when they are stretched?
a) cardiac muscle fibers
b) fast glycolytic fibers
c) fast oxidative-glycolytic fibers
d) slow oxidative fibers
e) single-unit smooth muscle fibers
e) single-unit smooth muscle fibers
69). Cross bridges are formed during muscle contraction when _____ on the thick filaments binds to _____ on the thin filaments.
a) myosin; troponin
b) myosin; troponin
c) myosin; actin
d) actin; myosin
e) actin; tropomyosin
c) myosin; actin
In a neuromuscular junction, the effect of acetylcholine (ACh) binding to receptors on the motor end plate lasts only briefly due to
a) rapid uptake of the ACh into the myofiber.
b) endocytosis of the ACh receptor into the myofiber.
c) rapid destruction of ACh in the synaptic cleft by acetylcholinesterase.
d) rapid destruction of ACh in the synaptic cleft by monoamine oxidase.
e) diffusion of the ACh out of the synaptic cleft.
c) rapid destruction of ACh in the synaptic cleft by acetylcholinesterase.
During which period of a twitch contraction does the muscle action potential move along the sarcolemma of the muscle cell and trigger calcium release into the sarcoplasm?
a) latent period
b) contraction period
c) relaxation period
d) absolute refractory period
e) relative refractory period
a) latent period
Which of following is a common characteristic of fast glycolytic (FG) skeletal muscle fibers?
a) large amount of myoglobin.
b) many mitochondria.
c) low concentration of creatine kinase in the sarcoplasm.
d) slow myosin ATPase.
e) high amount of glycogen in the sarcoplasm.
e) high amount of glycogen in the sarcoplasm.
Myasthenia Gravis is an autoimmune disorder that targets the ACh receptors at the NMJ and ultimately reduces the number of available receptors. Predict what happens if you treat the patient with a drug that inhibits the activity of acetylcholinesterase?
a) prevent contraction
b) weak contraction
c) normal contraction
d) cause spasm
e) none of these choices
c) normal contraction
74) Leg muscles are predominantly composed of which type of muscle fiber?
a) slow oxidative
b) fast glycolytic
c) fast oxidative-glycolytic
d) slow glycolytic
e) fast oxidative
fast oxidative-glycolytic
