Week 7 A&P Flashcards
How much of the total body weight of an average adult is muscle tissue?
a) 20-30%
b) 30-40%
c) 40-50%
d) 50-60%
e) 60-70%
c) 40-50%
Which of the following is NOT a major function of muscle tissue?
a) moving blood throughout the body
b) generating heat through contractions
c) stabilizing the movement of joints
d) promoting the movement of body structures
e) production of vitamins
e) production of vitamins
This is the property of muscle that gives it the ability to stretch without damage:
a) electrical excitability
b) contractility
c) extensibility
d) elasticity
e) thermogenesis
c) extensibility
This is the property of muscle that gives it the ability to stretch without damage:
a) electrical excitability
b) contractility
c) extensibility
d) elasticity
e) thermogenesis
c) extensibility
This is the outermost layer of connective tissue surrounding a skeletal muscle:
a) tendon
b) ligament
c) endomysium
d) epimysium
e) perimysium
d) epimysium
How many arteries and veins usually accompany a singe nerve penetrating a skeletal muscle?
a) one artery and one or two veins
b) two arteries and two veins
c) three arteries and two veins
d) one artery and three veins
e) one artery and a varied amount of veins
a) one artery and one or two veins
After the fusion of myoblasts, the muscle fiber loses its ability to do what?
a) grow
b) lengthen
c) contract
d) go through cell division
e) all of the answer choices
d) go through cell division
The mitochondria in skeletal muscle fiber are arranged:
a) randomly throughout the sarcoplasm
b) in circles around the T-tubules
c) around the nuclei
d) in rows near the contractile muscle proteins
e) close to the sarcolemma
d) in rows near the contractile muscle proteins
The contractile organelles of a skeletal muscle fiber are thread-like structures called:
a) myofibrils
b) myoglobin
c) mitochondria
d) Z discs
e) M lines
a) myofibrils
Release of calcium from these structures triggers skeletal muscle contraction
a) myofibrils
b) mitochondria
c) terminal cisterns of sarcoplasmic reticulum
d) T-tubules
e) none of the answer choices
c) terminal cisterns of sarcoplasmic reticulum
The sarcoplasmic reticulum reticulum in skeletal muscle fibers is used for storing
a) oxygen
b) ATP
c) PO43-.
d) Na+.
e) Ca2+.
e) Ca2+.
Myofibrils contain:
a) contractile proteins
b) regulatory proteins
c) structural proteins
d) all of these answers are correct
e) none of these answers are correct
d) all of these answers are correct
Which of the following functions as a motor protein in all three types of muscle tissue?
a) actin
b) myosin
c) troponin
d) titin
e) tropomyosin
b) myosin
What regulatory proteins can be found in the thin filaments of skeletal muscle fibres?
a) troponin and titin
b) tropomyosin and troponin
c) myosin and titin
d) titin and toposyosin
e) tropomyosin and myosin
b) tropomyosin and troponin
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
e) dystrophin
What energises the myosin head?
a) the actin filaments
b) calcium ions
c) potassium ions
d) ATP hydrolysis reaction
e) ADP synthesis
d) ATP hydrolysis reaction
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
To stimulate skeletal muscle contraction, acetylcholine must cross the __________ of the neuromuscular junction and bind to receptors on the motor endplate.
a) node of the Ranvier
b) synaptic cleft
c) sarcolemma
d) synaptic end bulb
e) transverse tubule
b) synaptic cleft
Which of teh following are commonly used to produce ATP during the 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
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
a) 15 seconds
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 autorythmic muscle fibres?
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 muscle cell’s cytosol?
a) ATP
b) calcium ions
c) phosphate ions
d) myoglobin
e) none of these choices
b) calcium ions
Hyperplasia is:
a) an increase in the size of muscle fibers
b) a decrease in the size of muscle fibers
c) an increase in the number of muscle fibers
d) a decrease in the number of muscle fibers
e) none of these choices
c) an increase is the number of muscle fibers
Which of the following disorders is characterised 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 of the following best describes the condition known as muscular hypertrophy?
a) decrease in diameter of muscle fibers
b) torn sarcolemmas and damaged myofibrils
c) increase in diameter of muscle fibres
d) actin and myosin remain attached by cross bridges and the muscle is rigid
e) damaged neuromuscular junctions
c) increase in diameter of muscle fibres
Which of the following is NOT seen in exercise-induced muscle damage?
a) torn sarcolemmas
b) damaged myofibrils
c) sore muscles
d) progressive degeneration of muscles
e) disrupted Z-discs
d) progressive degeneration of muscles
Which event does not occur during the onset of rigor mortis?
a) enzymes from lysosomes digest crossbridges
b) cellular membranes become leaky
c) myosin heads bind to actin
d) calcium ions leak out of the sarcoplasmic reticulum
e) ATP synthesis ceases
a) enzymes from lysosomes digest crossbridges
Which is the correct sequence of events in the onset of rigour mortis?
a) cellular membranes become leaky -> myosin heads bind to actin -> calcium ions leak into the sarcoplasm -> muscles are in a state of rigidity
b) cellular membranes become leaky -> calcium ions leak into the sarcoplasm -> myosin heads bind to actin -> muscles are in a state of rigidity
c) myosin heads bind to actin -> cellular membranes become leaky -> calcium ions leak into the sarcoplasm -> muscles are in a state of rigidity
d) calcium ions leak into the sarcoplasm -> cellular membranes become leaky -> myosin heads bind to actin -> muscles are in a state of rigidity
e) calcium ions leak into the sarcoplasm -> myosin heads bind into actin -> muscles are in a state of rigidity -> cellular membranes become leaky
b) cellular membranes become leaky -> calcium ions leak into the sarcoplasm -> myosin heads bind to actin -> muscles are in a state of rigidity
an EMG can be used to determine each of the following except:
a) the source of muscle weakness
b) paralysis due to muscle malfunction
c) paralysis due to nerve supplying the muscle
d) diagnose certain muscle disorders like muscular dystrophy
e) find the precise location of a muscle tumor
d) diagnose certain muscle disorders like muscular dystrophy
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
e) cramp
Which of the following types of abnormal contractions of skeletal muscle is a rhythmic, involuntary, purposeless quivering or shaking movement?
a) tetanus
b) fasciculation
c) tremor
d) fibrillation
e) cramp
c) tremor
Which of the following types of abnormal contractions of skeletal muscle is caused by a twitch of an entire motor unit an dis visible under the skin?
a) tic
b) fasciculation
c) tremor
d) fibrillation
e) cramp
b) fasciculation
Which of the following types of abnormal contractions of skeletal muscle is caused by a single muscular finer, is spontaneous, and is not visible under the skin?
a) tic
b) fasciculation
c) tremor
d) fibrillation
e) cramp
d) fibrillation
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
