Deck 10: Muscle Tissue

Question 1

During isotonic contraction, the heavier the load, the faster the velocity of muscle shortening.

Answer 1

False

Question 2

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 joints
D) promoting movement of body structures
E) storing energy

Answer 2

E

Question 3

When connective tissue extends as a broad flat layer, the tendon is referred to as

A) perimysium.
B) deep fascia.
C) fascicle.
D) aponeurosis.
E) endomysium.

Answer 3

D

Question 4

In an isometric contraction the muscle develops tension but does not

A) lengthen.
B) widen.
C) shorten.
D) conduct electrical current.
E) produce force.

Question 5

Which of the following statements is TRUE regarding Slow Oxidative fibers found in skeletal muscle?

A) They are large in diameter.
B) They are adapted for intense bursts of anaerobically fueled movement.
C) They contain vast stores of glycogen.
D) They contract slowly, but are resistant to fatigue.
E) They are the last fibers to be recruited in situations where maximal force is required.

Question 6

This part of the skeletal muscle cell releases calcium when stimulated by the T tubules.

A) myofibrils
B) sarcoplasm
C) terminal cisterns of sarcoplasmic reticulum
D) sarcomeres
E) sarcolemma

Question 7

Which one of these statements is FALSE?

A) The force of a muscle contraction increases as more motor units are activated.
B) Concentric isotonic contractions occur when the load equals or exceeds the tension produced in the muscle.
C) Recruitment is the process in which the number of motor units stimulated during a contraction is increased.
D) When a second stimulus occurs before the muscle has relaxed, wave summation occurs and the second contraction generates more force than the first contraction.
E) A motor unit is a motor neuron and all of the myofibers it innervates.

Question 8

After the fusion of myoblasts, the muscle fiber loses its ability to do what?

A) grow
B) lengthen
C) contract
D) go through mitosis
E) all of these choices

Question 9

What is occurring during this period of a muscle twitch contraction?

A) The muscle action potential sweeps along the sarcolemma and calcium ions are released from the sarcoplasmic reticulum.
B) Crossbridge attachments form, and repetitive power strokes occur.
C) The level of Ca²⁺ in the sarcoplasm decreases, because it is being actively transported back into the sarcoplasmic reticulum and bound to calsequestrin.
D) The muscle fiber relaxes as myosin heads detach from the actin filaments.
E) Acetylcholinesterase is preventing the ligand gated channels at the motor end plate from binding to ACh.

Question 10

Calcium ions bind to the ___ molecule in skeletal muscle cells.

A) actin
B) troponin
C) tropomyosin
D) myosin
E) titin

Question 11

Acetylcholine is broken down relatively quickly, and is done so by an enzyme called acetylcholinesterase.

Question 12

This is a band of connective tissue that surrounds whole muscles.

A) tendon
B) ligament
C) endomysium
D) epimysium
E) perimysium

Question 13

What is occurring during this period of a muscle twitch contraction?

A) The muscle action potential sweeps along the sarcolemma and calcium ions are released from the sarcoplasmic reticulum.
B) Ach binds to the ligand gated channels at the motor end plates.
C) The level of Ca²⁺ in the sarcoplasm decreases, because it is being actively transported back into the sarcoplasmic reticulum.
D) Calcium ions bind to Troponin.
E) Power strokes generate contractile force.

Question 14

These are the contractile organelles of the muscle fiber.

A) myofibrils
B) myoglobin
C) mitochondria
D) Z disc
E) M line

Question 15

Which of the following represents the sequence that muscle action potentials must go through to excite a muscle cell?

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

Question 16

Axon terminal clusters at the ends of motor neurons that are considered part of the neuromuscular junction are referred to as:

A) myelin bulbs
B) neuromuscular bulbs
C) synaptic end bulbs
D) axon collateral bulb
E) tubule bulb

Question 17

Which of the following statements is TRUE regarding Fast Glycolytic fibers found in skeletal muscle?

A) They are small in diameter.
B) They are adapted for intense bursts of anaerobically fueled movement.
C) They have abundant mitochondria.
D) They contract slowly, but are resistant to fatigue.
E) They contain vast quantities of myoglobin.

Question 18

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

Question 19

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) thermogenicity

Question 20

For every nerve that penetrates a skeletal muscle, there are in general how many arteries and veins?

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

Question 21

Which of the following is used to reinforce the sarcolemma?

A) troponin
B) tropomyosin
C) myosin
D) actin
E) dystrophin

Question 22

Which of the following contains thick filaments?

A) Zone of overlap
B) A band
C) H zone
D) both a band and h zone
E) all of these choices

Question 23

This phase is described as a muscle action potential propagating along the sarcolemma and into the T tubules.

A) contraction
B) relaxation
C) excitation
D) release channel
E) ATP hydrolysis

Question 24

What energizes the myosin head?

A) the actin filaments
B) calcium ions
C) potassium ions
D) hydrolysis of ATP
E) phosphorylation of ADP

Question 25

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

Question 26

The sarcoplasmic reticulum is used for storing

A) oxygen
B) ATP
C) myoglobin
D) Na⁺
E) Ca²⁺

Question 27

What is needed for the contraction cycle to continue?

A) ATP and Acetylcholine (ACh)
B) calcium ions and ATP
C) ACh and potassium
D) water and ATP
E) calcium ACh

Question 28

A single, brief contraction of all muscle fibers in a motor unit in response to a single action potential is called:

A) recovery oxygen uptake
B) motor unit movement
C) muscle fatigue
D) refractory period
E) twitch contraction

Question 29

The sarcoplasmic reticulum releases calcium ions into the cytosol

A) at the beginning of a contraction.
B) throughout the entire contraction.
C) during the midpoint only of the contraction.
D) after the contraction ends.
E) all of these choices.

Question 30

Creatine phosphate stores and ATP together create enough energy for a muscle to contract for

A) 15 seconds
B) 15 minutes
C) 1.5 minutes
D) Less than 5 seconds
E) One minute

Question 31

Titin is found in a sarcomere

A) in the A band only.
B) in the H zone only.
C) from the zone of overlap to the Z disc.
D) from the M line to the Z disc.
E) in the I band only.

Question 32

This is also referred to as the period of lost excitability.

A) refractory period
B) contraction period
C) latent period
D) relaxation period
E) wave summation

Question 33

This consists of a somatic motor neuron plus all the skeletal muscle fibers it stimulates.

A) sarcomere
B) motor unit
C) neuromuscular junction
D) somatic motor neuron
E) muscle fiber

Question 34

How many molecules of acetylcholine need to bind to open the ion channel of the ACh receptor?

A) 34
B) 5
C) 10
D) an unknown amount
E) 2

Question 35

Which of the following contains thin filaments?

A) I band
B) A band
C) H zone
D) both I band and A band
E) all of these choices

Question 36

In the sliding filament mechanism, the thin filament is being pulled towards the

A) Z disc.
B) H zone.
C) M line.
D) A band.
E) I band.

Question 37

What regulatory proteins can be found associated with an actin molecule?

A) troponin and titin
B) tropomyosin and troponin
C) myosin and titin
D) titin and tropomyosin
E) titin and calsequestrin

Question 38

Myofibrils contain

A) contractile proteins.
B) regulatory proteins.
C) structural proteins.
D) all of these choices.
E) none of these choices.

Question 39

How do muscles produce ATP?

A) creatine phosphate
B) anaerobic cellular respiration
C) aerobic cellular respiration
D) all of these choices
E) none of these choices

Question 40

The signal to excite a muscle cell must cross the neuromuscular junction by the diffusion of acetylcholine across the

A) motor neuron axon.
B) synaptic cleft.
C) sarcolemma.
D) synaptic vesicles.
E) myofibril.

Question 41

This is the least powerful type of muscle fiber:

A) slow oxidative fiber
B) fast oxidative fibers
C) fast glycolytic fibers
D) slow glycolytic fibers
E) all muscle fibers are equally capable of producing force

Question 42

A motor unit

A) is usually composed of different muscle fiber types.
B) is comprised of a single motor neuron and all the muscle fibers it innervates.
C) can determine whether to contract one of its associated fibers or all of them depending on the load.
D) consists of a fascicle, a myofiber, and its myofibrils.
E) is comprised of a motor neuron and the fascicle it innervates.

Question 43

Which of the following statements best describes Slow Oxidative muscle fibers?

A) They are large in diameter.
B) They are resistant to fatigue.
C) They have few mitochondria.
D) The rate of ATP hydrolysis on the myosin head is very fast.
E) They have very little myoglobin.

Question 44

Which of the following statements is FALSE regarding whole muscle contraction?

A) Wave summation occurs as a result of increased frequency of stimulation.
B) The amount of force produced must exceed the load in order to produce muscle shortening.
C) Isometric contractions happen when tension is developed but muscle shortening does not occur.
D) The duration of a contraction depends in part on the type of skeletal muscle fibers making up the motor unit.
E) Increasing the frequency of stimulation results in motor unit recruitment.

Question 45

Hypertrophy 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) a loss in size and strength of muscle fibers.

Question 46

Which of the following statements is TRUE regarding skeletal muscle contraction?

A) During the excitation phase, Ca²⁺ enters the motor neuron through chemically gated channels and causes exocytosis of acetylcholine into the synaptic cleft.
B) An action potential is generated and propagated along the sarcolemma due to K⁺ influx through voltage gated channels.
C) The myosin head binds to the actin receptor region once it has hydrolyzed ATP and the regulatory proteins (Troponin and tropomyosin) have been "pulled out of the way."
D) The powerstroke occurs immediately after the myosin head has hydrolyzed the ATP molecule.
E) ATP is necessary for coupling to occur, however, Ca²⁺ is only used during maximal force contractions.

Question 47

Atrophy 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) a loss in size and strength of muscle fibers

Question 48

Acetylcholine binds to and opens chemically gated channels located within the ___.

A) synaptic cleft
B) synaptic end bulb
C) T tubules
D) motor end plate
E) myofibril

Question 49

On the diagram, where is the deep fascia?

A) A
B) B
C) C
D) D
E) E

Question 50

A unique characteristic of cardiac muscle tissue is:

A) myosin
B) tropomysoin
C) sarcomeres
D) intercalated discs
E) striations

Question 51

Which of the following exhibits autorhythmicity?

A) cardiac muscle fibers
B) actin fibers
C) visceral smooth muscle fibers
D) intermediate fibers
E) both cardiac muscle fibers and visceral smooth muscle fibers

Question 52

Smooth muscle tone is due to the prolonged presence of this material in the cytosol?

A) ATP
B) calcium ions
C) phosphate ions
D) myoglobin
E) none of these choices

Question 53

Skeletal muscle cells

A) are nonstriated.
B) are involuntary.
C) have a single, central nucleus.
D) can be as much as a foot long.
E) have scant sarcoplasmic reticulum.

Question 54

Increasing the number of active motor units is called:

A) wave summation
B) fused tetanus
C) motor unit recruitment
D) muscle tone
E) unfused tetanus

Question 55

Which of the following is NOT a correct structure and tissue type pairing?

A) endomysium : loose areolar connective tissue
B) perimysium : dense irregular connective tissue
C) tendon : dense regular connective tissue
D) sarcolemma : loose areolar connective tissue
E) epimysium: dense irregular connective tissue

Question 56

Which of the following surrounds the individual muscle cell?

A) perimysium
B) endomysium
C) epimysium
D) fascicle
E) deep fascia

Question 57

Which of the following statements is FALSE regarding a sarcomere?

A) It is the basic functional unit of a myofibril.
B) It extends from one Z-disc to another Z-disc.
C) It contains the I-band, which is composed of actin and myosin myofilaments.
D) It contains an H-zone, whose length may shorten during a contraction.
E) It contains regulatory, structural, and contractile proteins.

Question 58

Which of the following statements is TRUE regarding the production of ATP in skeletal muscle fibers?

A) Short burst activities (such as sprints) rely mainly on anaerobic production of ATP.
B) Creatine phosphate can be broken down to provide enough ATP to fuel activities such as marathon running.
C) Glucose is broken down during glycolysis in order to produce ATP aerobically.
D) Skeletal muscle is unable to produce ATP anaerobically.
E) Vast amounts of myoglobin is stored in fast glycolytic fibers in order to produce ATP aerobically.

Question 59

Which of the following is composed of areolar connective tissue?

A) endomysium
B) epimysium
C) perimysium
D) T tubules
E) sarcolemma

Question 60

A sustained contraction during which individual muscle twitches cannot be detected is called:

A) myogram
B) muscle tone
C) wave summation
D) fused tetanus
E) twitch

Question 61

In the diagram, where is the T tubule?

A) K
B) J
C) L
D) M
E) D

Question 62

Which structure on this diagram allows free movement of muscles, carries nerves, blood vessels and lymphatic vessels and fills spaces between whole muscles.

A) A
B) B
C) E
D) G
E) H

Question 63

In the diagram, what is the basic functional unit of a myofibril?

A) B
B) C
C) F
D) Both B and C
E) All of these choices

Question 64

What letter indicates the fascicle on the diagram?

A) E
B) F
C) I
D) G
E) B

Question 65

In the diagram, where are the synaptic end bulbs located?

A) B
B) C
C) D
D) G
E) H

Question 66

In the diagram, where is the skeletal muscle fiber?

A) A
B) B
C) C
D) D
E) E

Question 67

In the diagram, where is the I band?

A) G
B) H
C) I
D) J
E) D

Question 68

In the diagram, where would you find stored Ca²⁺?

A) B
B) D
C) E
D) F
E) G

Question 69

In the diagram, where is the axon collateral?

A) B
B) C
C) D
D) E
E) None of these choices

Question 70

In the diagram, which structure is only a structural protein?

A) B
B) C
C) E
D) Both B and C
E) All of these choices

Question 71

In the diagram, what is made from dense regular connective tissue?

A) A
B) H
C) C
D) D
E) All of these choices

Question 72

In the diagram, what letter indicates a triad?

A) G
B) E
C) D
D) F
E) C

Question 73

In the diagram, which is a myofilament?

A) A
B) B
C) H
D) C
E) G

Question 74

In the diagram, which parts make up the neuromuscular junction?

A) A, B, E
B) C, A, B, E
C) B, E
D) A, B, C, D, E
E) C, E

Question 75

In the diagram, what is made from dense irregular connective tissue?

A) D
B) C
C) H
D) A
E) Both D and H

Question 76

In the diagram, where is the A band?

A) G
B) H
C) I
D) J
E) None of these choices

Question 77

In the diagram, which are regulatory proteins?

A) B
B) C
C) E
D) All of these choices
E) None of these choices

Question 78

In the diagram, where is the thin filament?

A) G
B) H
C) I
D) J
E) None of these choices

Question 79

In the diagram, which are motor proteins?

A) C
B) A
C) E
D) D
E) None of these choices

Question 80

In the diagram, where is the muscle fiber located?

A) E
B) F
C) G
D) B
E) I