Chapter 10 A&P study guide

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 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

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.

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

During this period of a twitch contraction, the muscle action potential moves along the sarcolemma of the muscle cell and triggers 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

In an isometric contraction the muscle develops tension but does not A) lengthen. B) widen. C) does not expend energy. D) conduct electrical current. E) exhibit elasticity.

A) lengthen

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.

A structural protein that is associated with thin filaments and serves to anchor the thin filament to the Z-disc is called A) nebulin. B) titin. C) myomesin. D) dystrophin. E) tropomyosin

A) nebulin

How many arteries and veins usually accompany a single 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 viens

This is also 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

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 is a correct sequence of events in the onset of rigor 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 to 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.

Which is a NOT a side-effect of anabolic steroid use by female athletes? A) sterility B) baldness C) facial hair growth D) menstrual irregularities E) deepening of the voice

B) baldness

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

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

Which of the following types of abnormal contractions of skeletal muscle is caused by a twitch of an entire motor unit and is visible under the skin? A) tic B) fasciculation C) tremor D) fibrillation E) cramp

B) fasciculation

Biceps are predominantly composed of this type of muscle fiber. A) slow oxidative B) fast glycolytic C) fast oxidative-glycolytic D) slow glycolytic E) fast oxidative

B) fast glycolytic

This 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

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

B) muscular atrophy

On which of the following proteins is the enzyme ATPase located? A) actin B) myosin C) titin D) dystrophin E) troponin

B) myosin

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

Cross bridges are formed during muscle contraction when _____ on the thick filaments binds to ______ on the thin filaments. A) myosin; troponin B) myosin; actin C) actin; myosin D) actin; tropomyosin E) myosin; tropomyosin

B) myosin; actin

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 left

What regulatory proteins can be found in the thin filaments of skeletal muscle fibers? A) troponin and titin B) tropomyosin and troponin C) myosin and titin D) titin and tropomyosin E) tropomyosin and myosin

B) tropomyosin and troponin

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

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

D) All of these choices

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.

Which of the following regions of a sarcomere contain thin filaments? A) I band B) A band C) H zone D) Both I band and A band. E) All of these answer choices are correct

D) Both I band and A band

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.

The type of tendon formed when the connective tissue elements of a skeletal muscle extend as a broad flat layer. A) perimysium B) deep fascia C) fascicle D) aponeurosis E) endomysium

D) aponeurosis

Which of the following correctly lists the sequence of structures that action potentials must move through to excite skeletal muscle contraction? A) sarcolemma, axon of neuron, T tubules B) T tubules, sarcolemma, myofilament C) muscle fiber, axon of neuron, myofibrils D) axon of neuron, sarcolemma, T tubules E) myofibrils, myofilaments, mitochondria

D) axon of neuron, sarcolemma, T tubles

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

This is the outermost layer of connective tissue surrounding a skeletal muscle. A) tendon B) ligament C) endomysium D) epimysium E) perimysium

D) epimysium

Which of the following types of abnormal contractions of skeletal muscle is caused by a single muscle fiber, is spontaneous, and is not visible under the skin? A) tic B) fasciculation C) tremor D) fibrillation E) cramp

D) fibrillation

Which of the regions of a sarcomere contain titin? A) the A band only B) the H zone only C) the zone of overlap only D) from M line to Z disc E) the I band only

D) from M line to Z disc

A period of sustained skeletal muscle contraction in which individual twitches cannot be detected is called A) unfused tetanus. B) muscle atrophy. C) flaccidity. D) fused tetanus. E) wave summation

D) fused tetanus

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

After several visits to the gym and serious "iron pumping" (strength training) you notice that your biceps have enlarged. Which one of the following has happened to your muscles? A) atrophy B) dystrophy C) hyperplasia D) hypertrophy E) heterotrophy

D) hypertrophy

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.

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 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

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) progessive degeneration of muscles

Which of the following is NOT a common side effect of creatine supplementation? A) decrease in the body's own synthesis of creatine B) kidney dysfunction C) dehydration D) all of these choices E) rigor mortis

E) rigor mortis

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

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

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%

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) Cause spasm

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.

C) M line

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 in the number of muscle fibers

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

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

C) fast oxidative-glycolytic

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 fibers D) actin and myosin remain attached by crossbridges and the muscle is rigid E) damaged neuromuscular junctions

C) increase in diameter of muscle fibers

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

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

In neuromuscular junctions, synaptic vesicles containing acetylcholine are found suspended in the cytosol of A) myelin bulbs. B) neuromuscular bulbs. C) synaptic end bulbs. D) axon collateral bulbs. E) tubule bulbs.

C) synaptic end bulbs

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

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 regions of the sarcomere contain thick filaments? A) zone of overlap B) A band C) H zone D) both A band and H zone E) All of these answer choices are correct.

E) All of these answer choices are correct.

The different types of muscle tissue differ from each other by A) microscopic anatomy. B) location. C) type of Control. D) both microscopic anatomy and location. E) All of these choices are correct.

E) All of these choices are correct.

The sarcoplasmic reticulum in skeletal muscle fibers is used for storing A) oxygen. B) ATP. C) PO43-. D) Na+. E) Ca2+.

E) Ca2+

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 movement of body structures E) Production of Vitamins.

E) Production of Vitamins

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 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

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.

E) find the precise location of a muscle tumor

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