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Committee Exam 4 > TEST 11 > Flashcards

TEST 11 Flashcards

1
Q

Which of the following is not a component of a skeletal muscle cell?
a) Sarcomere
b) Myofibril
c) Sarcoplasmic reticulum
d) Sarcolemma

A

Sarcomere

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2
Q

The basic functional unit of skeletal muscle is called:
a) Myofibril
b) Myofilament
c) Sarcomere
d) Myotendon junction

A

Sarcomere

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3
Q

The contraction of skeletal muscles is initiated by the release of which ion?
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Magnesium (Mg2+)

A

Calcium (Ca2+)

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4
Q

During muscle contraction, which protein binds with calcium ions to initiate the cross-bridge formation?
a) Actin
b) Myosin
c) Troponin
d) Tropomyosin

A

Troponin

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5
Q

The neurotransmitter responsible for transmitting the signal from the nerve to the skeletal muscle cell is:
a) Acetylcholine
b) Serotonin
c) Dopamine
d) Epinephrine

A

Acetylcholine

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6
Q

The region where the motor neuron meets the skeletal muscle fiber is known as:
a) Synaptic cleft
b) Axon terminal
c) Neuromuscular junction
d) Motor end plate

A

Neuromuscular junction

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7
Q

Which of the following events occurs at the neuromuscular junction?
a) Release of acetylcholine
b) Activation of voltage-gated calcium channels
c) Binding of acetylcholine to postsynaptic receptors
d) All of the above

A

All of the above

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8
Q

Myasthenia gravis is an autoimmune disorder that affects the:
a) Skeletal muscles
b) Cardiac muscles
c) Smooth muscles
d) Both a) and b)

A

Skeletal muscles

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9
Q

Muscular dystrophy is a genetic disorder that primarily affects the:
a) Nervous system
b) Skeletal muscles
c) Cardiovascular system
d) Respiratory system

A

Skeletal muscles

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10
Q

Rigor mortis is caused by the depletion of:
a) Adenosine triphosphate (ATP)
b) Calcium ions (Ca2+)
c) Acetylcholine (ACh)
d) Sodium ions (Na+)

A

Adenosine triphosphate (ATP)

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11
Q

The structural and functional unit of a skeletal muscle is the ______________.

A

Muscle fiber

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12
Q

The ______________ is the plasma membrane of a muscle cell.

A

Sarcolemma

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13
Q

The contractile proteins found within a sarcomere are ______________ and ______________.

A

Actin and myosin

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14
Q

During muscle contraction, calcium binds to ______________, which moves ______________, exposing myosin-binding sites on actin.

A

Troponin, tropomyosin

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15
Q

The neurotransmitter ______________ is released from the motor neuron to initiate a muscle contraction.

A

Acetylcholine

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16
Q

Skeletal muscle cells are multinucleated. True or False?

A

True

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17
Q

Tropomyosin covers the myosin-binding sites on actin in a relaxed muscle. True or False?

A

True

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18
Q

Rigor mortis is a temporary state of muscle stiffness that occurs after death. True or False?

A

True

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19
Q

Myasthenia gravis is an autoimmune disorder characterized by the excessive release of acetylcholine. True or False?

A

False

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20
Q

Muscular dystrophy is caused by a mutation in the dystrophin gene, leading to muscle weakness and degeneration. True or False?

A

True

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21
Q

Which protein forms the thin filaments in a sarcomere?
a) Myosin
b) Tropomyosin
c) Troponin
d) Actin

A

Actin

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22
Q

Which of the following is responsible for storing and releasing calcium ions during muscle contraction?
a) Sarcoplasmic reticulum
b) Sarcolemma
c) T-tubules
d) Myofibrils

A

Sarcoplasmic reticulum

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23
Q

The functional connection between a motor neuron and a skeletal muscle fiber is called a:
a) Synapse
b) Gap junction
c) Desmosome
d) Sarcomere

A

Synapse

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24
Q

The process of muscle relaxation occurs when calcium ions are actively pumped back into the:
a) Motor neuron
b) Sarcolemma
c) T-tubules
d) Sarcoplasmic reticulum

A

Sarcoplasmic reticulum

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25
Q

Which of the following is a characteristic feature of myasthenia gravis?
a) Muscle wasting and weakness
b) Elevated levels of calcium ions
c) Hyperactivity of motor neurons
d) Enhanced muscle contractions

A

Muscle wasting and weakness

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26
Q

Which type of muscular dystrophy primarily affects boys and leads to progressive muscle weakness and loss of coordination?
a) Duchenne muscular dystrophy
b) Becker muscular dystrophy
c) Myotonic dystrophy
d) Facioscapulohumeral dystrophy

A

Duchenne muscular dystrophy

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27
Q

Rigor mortis occurs due to the inability of muscle cells to produce:
a) Oxygen
b) ATP
c) Acetylcholine
d) Calcium ions

A

ATP

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28
Q

Which of the following structures is responsible for transmitting action potentials deep into the muscle fiber?
a) Sarcolemma
b) T-tubules
c) Sarcoplasmic reticulum
d) Myofibrils

A

T-tubules

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29
Q

In myasthenia gravis, autoantibodies attack and destroy:
a) Motor neurons
b) Neurotransmitters
c) Acetylcholine receptors
d) Muscle fibers

A

Acetylcholine receptors

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30
Q

Which of the following is a characteristic feature of Duchenne muscular dystrophy?
a) Late onset in adulthood
b) Muscle weakness limited to the upper body
c) Abnormalities in dystrophin protein
d) Slowed muscle relaxation

A

Abnormalities in dystrophin protein

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31
Q

The ______________ is the contractile unit of a muscle fiber.

A

Sarcomere

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32
Q

The neurotransmitter ______________ is responsible for muscle relaxation.

A

Acetylcholine

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33
Q

The enzyme ______________ breaks down acetylcholine in the synaptic cleft.

A

Acetylcholinesterase

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34
Q

The phenomenon of muscle contraction without a change in muscle length is known as ______________.

A

Isometric contraction

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35
Q

The protein ______________ forms the backbone of the thin filaments.

A

Actin

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36
Q

The sliding filament theory explains the mechanism of muscle contraction. True or False?

A

True

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37
Q

Motor units consist of a single motor neuron and multiple muscle fibers. True or False?

A

True

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38
Q

Excitation-contraction coupling refers to the sequence of events that link muscle excitation (action potential) to muscle contraction. True or False?

A

True

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39
Q

Muscle dystrophy is characterized by the progressive degeneration and weakening of cardiac muscles. True or False?

A

False

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40
Q

Rigor mortis typically begins within a few minutes after death and lasts for several hours before the muscles start to relax. True or False?

A

True

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41
Q

Smooth muscle is primarily composed of:
a) Sarcomeres
b) Actin and myosin filaments
c) Troponin and tropomyosin
d) Z discs and I bands

A

Actin and myosin filaments

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42
Q

Which of the following is not a type of smooth muscle?
a) Multiunit smooth muscle
b) Single-unit smooth muscle
c) Skeletal smooth muscle
d) Visceral smooth muscle

A

Skeletal smooth muscle

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43
Q

Smooth muscles are found in which of the following organs?
a) Heart and lungs
b) Intestines and blood vessels
c) Biceps and quadriceps
d) Liver and pancreas

A

Intestines and blood vessels

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44
Q

Smooth muscle contraction is regulated by which ion?
a) Sodium (Na+)
b) Calcium (Ca2+)
c) Potassium (K+)
d) Chloride (Cl-)

A

Calcium (Ca2+)

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45
Q

The autonomic nervous system innervates smooth muscles through the release of:
a) Acetylcholine
b) Norepinephrine
c) Dopamine
d) Serotonin

A

Acetylcholine

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46
Q

Smooth muscles exhibit which of the following properties?
a) Voluntary control
b) Striated appearance
c) Spontaneous contraction
d) Rapid fatigue

A

Spontaneous contraction

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47
Q

Smooth muscle contraction is characterized by the formation of:
a) Sarcomeres
b) Cross-bridges
c) Motor end plates
d) Neuromuscular junctions

A

Cross-bridges

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48
Q

Which of the following substances is responsible for smooth muscle relaxation?
a) Acetylcholine
b) Calcium ions
c) Nitric oxide
d) Sodium ions

A

Nitric oxide

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49
Q

Smooth muscle plays a crucial role in the regulation of which bodily functions?
a) Digestion and blood pressure
b) Vision and hearing
c) Skeletal movement and balance
d) Breathing and heartbeat

A

Digestion and blood pressure

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50
Q

Compared to skeletal muscle, smooth muscle cells have:
a) More sarcomeres
b) Fewer actin and myosin filaments
c) Striated appearance
d) Greater ability to generate force

A

Greater ability to generate force

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51
Q

Smooth muscle cells are elongated and tapered, with a single ________________.

A

Nucleus

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52
Q

______________ smooth muscle is found in the walls of large arteries and airways.

A

Multiunit

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53
Q

The process of smooth muscle relaxation involves the dephosphorylation of ________________.

A

Myosin

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54
Q

Smooth muscle is innervated by the autonomic division of the ________________ nervous system.

A

Peripheral

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55
Q

Smooth muscles play a role in the movement of substances through various organs, such as the ________________ and ________________.

A

Stomach, intestines

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56
Q

Smooth muscle lacks striations and sarcomeres. True or False?

A

True

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57
Q

Smooth muscle cells are not under conscious control. True or False?

A

True

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58
Q

Smooth muscle contracts more slowly but can sustain contractions longer than skeletal muscle. True or False?

A

True

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59
Q

Smooth muscle contractions are dependent on the presence of calcium ions. True or False?

A

True

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60
Q

Smooth muscle is capable of generating a greater degree of force than skeletal muscle. True or False?

A

False

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61
Q

Smooth muscle cells possess a single nucleus. True or False?

A

True

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62
Q

Smooth muscles are present in the walls of blood vessels, contributing to blood pressure regulation. True or False?

A

True

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63
Q

Smooth muscle contraction can occur spontaneously, without nerve stimulation. True or False?

A

True

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64
Q

Smooth muscle cells can divide and regenerate more readily than skeletal muscle cells. True or False?

A

True

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65
Q

Smooth muscle is found in the urinary bladder, allowing it to stretch and accommodate urine. True or False?

A

True

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66
Q

Smooth muscle is not involved in voluntary movements. True or False?

A

True

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67
Q

Smooth muscle relaxation is mediated by the release of nitric oxide. True or False?

A

True

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68
Q

Smooth muscle contractions are slower but can be sustained for longer periods compared to skeletal muscle contractions. True or False?

A

True

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69
Q

Smooth muscles are less resistant to fatigue than skeletal muscles. True or False?

A

False

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70
Q

Smooth muscle is innervated by both the sympathetic and parasympathetic divisions of the autonomic nervous system. True or False?

A

True

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71
Q

Smooth muscles are involuntary, while skeletal muscles are voluntary. True or False?

A

True

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72
Q

Smooth muscles lack striations, while skeletal muscles are striated. True or False?

A

True

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73
Q

Smooth muscles contract and relax more slowly than skeletal muscles. True or False?

A

True

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74
Q

Smooth muscles exhibit spontaneous contractions, while skeletal muscles require nerve stimulation to contract. True or False?

A

True

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75
Q

Smooth muscles can generate force for longer periods than skeletal muscles. True or False?

A

True

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76
Q

Smooth muscles have a single nucleus per cell, while skeletal muscles have multiple nuclei. True or False?

A

True

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77
Q

Smooth muscles are found in various organs and blood vessels, while skeletal muscles are attached to bones. True or False?

A

True

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78
Q

Smooth muscles play a role in regulating processes such as digestion and blood pressure, while skeletal muscles enable voluntary movements. True or False?

A

True

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79
Q

Smooth muscles are more resistant to fatigue than skeletal muscles. True or False?

A

True

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80
Q

Smooth muscles are innervated by the autonomic nervous system, while skeletal muscles are innervated by the somatic nervous system. True or False?

A

True

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81
Q

Which of the following is not a layer of the heart wall?
a) Epicardium
b) Myocardium
c) Endocardium
d) Pericardium

A

Pericardium

82
Q

Cardiac muscle cells are connected by specialized cell-to-cell junctions called:
a) Intercalated discs
b) Sarcomeres
c) Z lines
d) T-tubules

A

Intercalated discs

83
Q

The contraction of cardiac muscle is regulated by which of the following ions?
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)

A

Calcium (Ca2+)

84
Q

The action potential in cardiac muscle is characterized by which of the following phases?
a) Depolarization, plateau, repolarization
b) Depolarization, repolarization, hyperpolarization
c) Resting, depolarization, repolarization
d) Excitation, contraction, relaxation

A

Depolarization, plateau, repolarization

85
Q

The prolonged action potential in cardiac muscle cells is primarily due to the influx of which ion?
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)

A

Calcium (Ca2+)

86
Q

Excitation-contraction coupling in cardiac muscle involves the release of calcium ions from which structure?
a) Sarcoplasmic reticulum
b) Sarcolemma
c) T-tubules
d) Myofibrils

A

Sarcoplasmic reticulum

87
Q

An increase in extracellular calcium levels leads to which of the following effects on cardiac muscle contraction?
a) Increased contraction strength
b) Decreased contraction strength
c) No effect on contraction strength
d) Prolonged relaxation

A

Increased contraction strength

88
Q

Potassium ions play a crucial role in cardiac muscle repolarization by:
a) Enhancing calcium influx
b) Facilitating sodium efflux
c) Reducing potassium efflux
d) Increasing chloride influx

A

Facilitating sodium efflux

89
Q

Hyperkalemia, or high levels of potassium in the blood, can lead to:
a) Increased heart rate
b) Decreased heart rate
c) Irregular heart rhythms
d) Weakening of heart contractions

A

Irregular heart rhythms

90
Q

How does an increase in temperature affect the contractility of cardiac muscle?
a) Increases contractility
b) Decreases contractility
c) Has no effect on contractility
d) Leads to muscle fatigue

A

Increases contractility

91
Q

The microscopic functional unit of cardiac muscle is called the ________________.

A

Sarcomere

92
Q

The depolarization phase of the cardiac action potential is primarily due to the influx of ________________ ions.

A

Sodium (Na+)

93
Q

The plateau phase of the cardiac action potential is caused by the influx of ________________ ions and efflux of ________________ ions.

A

Calcium (Ca2+), Potassium (K+)

94
Q

In excitation-contraction coupling, the binding of calcium ions to ________________ allows for cross-bridge formation.

A

Troponin

95
Q

Increased extracellular ________________ levels can lead to increased cardiac muscle contraction.

A

Calcium (Ca2+)

96
Q

The myocardium is the thickest layer of the heart wall. True or False?

A

True

97
Q

Intercalated discs in cardiac muscle allow for rapid electrical and mechanical coupling between cells. True or False?

A

True

98
Q

The prolonged action potential in cardiac muscle is primarily due to the slow influx of sodium ions. True or False?

A

True

99
Q

The refractory period in cardiac muscle is longer than in skeletal muscle, allowing for complete relaxation and filling of the heart chambers. True or False?

A

True

100
Q

Cardiac muscle contraction is primarily regulated by the autonomic nervous system. True or False?

A

True

101
Q

In excitation-contraction coupling, calcium ions bind to troponin, causing a conformational change that exposes myosin-binding sites on actin. True or False?

A

True

102
Q

An increase in extracellular potassium levels can lead to cardiac arrhythmias. True or False?

A

True

103
Q

Hypercalcemia, or high levels of calcium in the blood, can lead to increased heart rate and stronger contractions. True or False?

A

True

104
Q

Cardiac muscle contraction is independent of extracellular calcium levels. True or False?

A

False

105
Q

An increase in temperature enhances the contractility of cardiac muscle. True or False?

A

True

106
Q

Hypokalemia, or low levels of potassium in the blood, can lead to weakened heart contractions. True or False?

A

True

107
Q

The action potential in cardiac muscle cells is longer than in skeletal muscle cells. True or False?

A

True

108
Q

Cardiac muscle cells are interconnected by gap junctions, allowing for the spread of electrical signals and coordinated contraction. True or False?

A

True

109
Q

The influx of calcium ions triggers the release of more calcium ions from the sarcoplasmic reticulum in cardiac muscle. True or False?

A

True

110
Q

The resting membrane potential of cardiac muscle cells is around -90 mV. True or False?

A

True

111
Q

Which of the following is responsible for initiating the electrical signal in the heart?
a) Sinoatrial (SA) node
b) Atrioventricular (AV) node
c) Bundle of His
d) Purkinje fibers

A

Sinoatrial (SA) node

112
Q

Cardiac muscle cells are characterized by their ability to generate spontaneous action potentials due to the presence of:
a) Gap junctions
b) Pacemaker cells
c) T-tubules
d) Sarcomeres

A

Pacemaker cells

113
Q

The term “preload” refers to:
a) The force exerted by blood against the walls of blood vessels
b) The volume of blood in the ventricles at the end of diastole
c) The pressure in the aorta during systole
d) The amount of calcium available for muscle contraction

A

The volume of blood in the ventricles at the end of diastole

114
Q

The “afterload” of the heart refers to:
a) The force exerted by blood against the walls of blood vessels
b) The volume of blood in the ventricles at the end of diastole
c) The pressure in the aorta during systole
d) The amount of calcium available for muscle contraction

A

The pressure in the aorta during systole

115
Q

The Frank-Starling mechanism refers to:
a) The ability of the heart to contract spontaneously
b) The coordination between the SA node and the AV node
c) The relationship between stroke volume and end-diastolic volume
d) The transmission of electrical signals through gap junctions

A

The relationship between stroke volume and end-diastolic volume

116
Q

Cardiac muscle is characterized by the presence of ________________, which are invaginations of the sarcolemma that allow for rapid propagation of the action potential.

A

T-tubules

117
Q

The ________________ is the region of the heart that contains a dense network of specialized conducting cells responsible for the rapid transmission of electrical signals.

A

Atrioventricular (AV) node

118
Q

During the plateau phase of the cardiac action potential, ________________ channels open, causing an influx of calcium ions.

A

L-type (slow) calcium

119
Q

The process by which calcium ions are actively pumped out of the cytosol back into the sarcoplasmic reticulum is called ________________.

A

Calcium reuptake

120
Q

The ________________ reflex is a protective mechanism that increases heart rate and contractility in response to decreased blood volume or pressure.

A

Bainbridge reflex

121
Q

The myocardium is composed of cardiac muscle cells. True or false?

A

True

122
Q

The repolarization phase of the cardiac action potential is primarily due to the efflux of potassium ions. True or false?

A

True

123
Q

The atria contract simultaneously, followed by the contraction of the ventricles. True or false?

A

False

124
Q

Cardiac muscle cells are capable of undergoing mitosis and regenerating damaged tissue. True or false?

A

False

125
Q

The release of acetylcholine by the parasympathetic nervous system decreases heart rate. True or false?

A

True

126
Q

An increase in extracellular potassium levels can lead to cardiac arrest. True or false?

A

True

127
Q

An increase in extracellular calcium levels decreases the force of cardiac muscle contraction. True or false?

A

False

128
Q

Which of the following is the resting membrane potential of a typical neuron?
a) -70 mV
b) +30 mV
c) -90 mV
d) +60 mV

A

-70 mV

129
Q

Action potentials are typically generated by which type of cells?
a) Neurons
b) Muscle cells
c) Epithelial cells
d) Connective tissue cells

A

Neurons

130
Q

The depolarization phase of an action potential is primarily caused by the influx of which ion?
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)

A

Sodium (Na+)

131
Q

Which of the following is responsible for propagating an action potential along an axon?
a) Myelin sheath
b) Nodes of Ranvier
c) Axon terminals
d) Dendrites

A

Nodes of Ranvier

132
Q

Which of the following best defines homeostasis?
a) The maintenance of a constant internal environment
b) The regulation of temperature in the body
c) The balance between water intake and output
d) The response to external stimuli

A

The maintenance of a constant internal environment

133
Q

Which organ is primarily responsible for the regulation of blood glucose levels?
a) Lungs
b) Liver
c) Kidneys
d) Pancreas

A

Pancreas

134
Q

The process of digestion primarily occurs in which organ system?
a) Respiratory system
b) Cardiovascular system
c) Digestive system
d) Muscular system

A

Digestive system

135
Q

Which of the following is not a mechanism for regulating bodily fluids?
a) Osmosis
b) Filtration
c) Diffusion
d) Peristalsis

A

Peristalsis

136
Q

Which of the following is a characteristic of a negative feedback control system?
a) It amplifies the initial stimulus
b) It maintains homeostasis by opposing the initial change
c) It requires the activation of multiple effectors
d) It is rarely found in biological systems

A

It maintains homeostasis by opposing the initial change

137
Q

The concentration of which ion is higher inside the cell compared to the outside during the resting membrane potential?
a) Sodium (Na+)
b) Potassium (K+)
c) Calcium (Ca2+)
d) Chloride (Cl-)

A

Potassium (K+)

138
Q

Action potentials are generated when the membrane potential reaches the ________________ threshold.

A

Excitation or firing

139
Q

The movement of ions across the cell membrane is regulated by ________________ channels.

A

Ion or protein

140
Q

Homeostasis is maintained through ________________ feedback mechanisms.

A

Negative

141
Q

In the lungs, ________________ is responsible for the exchange of oxygen and carbon dioxide.

A

Diffusion

142
Q

The liver plays a key role in detoxifying ________________ and storing ________________.

A

Substances or chemicals; glycogen

143
Q

Membrane potential refers to the electrical charge difference across a cell membrane. True or false?

A

True

144
Q

Action potentials are all-or-none responses. True or false?

A

True

145
Q

Physiology is the study of the functions and processes of living organisms. True or false?

A

True

146
Q

The digestive system is responsible for the absorption of nutrients into the bloodstream. True or false?

A

True

147
Q

Positive feedback mechanisms are more common in maintaining homeostasis than negative feedback mechanisms. True or false?

A

False

148
Q

The liver produces bile, which aids in the digestion and absorption of fats. True or false?

A

True

149
Q

Osmosis is the movement of water molecules from an area of high solute concentration to an area of low solute concentration. True or false?

A

False

150
Q

The hypothalamus plays a key role in regulating body temperature. True or false?

A

True

151
Q

The stomach produces hydrochloric acid, which aids in the digestion of proteins. True or false?

A

True

152
Q

Control systems in the body can be classified as neural or hormonal. True or false?

A

True

153
Q

The process of filtration occurs in the kidneys to remove waste products from the blood. True or false?

A

True

154
Q

The movement of ions across the cell membrane is an active process that requires energy. True or false?

A

True

155
Q

Homeostasis is a dynamic process that constantly adjusts to external and internal changes. True or false?

A

True

156
Q

Diffusion is a passive process that does not require energy expenditure. True or false?

A

True

157
Q

The control center in a feedback system receives information from the receptor and initiates an appropriate response. True or false?

A

True

158
Q

Which of the following is responsible for transmitting electrical signals between neurons?
a) Synapse
b) Mitochondria
c) Nucleus
d) Golgi apparatus

A

Synapse

159
Q

Homeostasis involves maintaining a stable internal environment regardless of external conditions. True or false?

A

True

160
Q

The movement of substances against their concentration gradient requires ________________.

A

Energy or ATP

161
Q

Organic chemistry is the study of:
a) Carbon-based compounds
b) Inorganic compounds
c) Mineralogy
d) Physical properties of elements

A

Carbon-based compounds

162
Q

Who is known as the “father of organic chemistry”?
a) Linus Pauling
b) Friedrich Wöhler
c) Dmitri Mendeleev
d) Marie Curie

A

Friedrich Wöhler

163
Q

How many atomic orbitals are there in the second electron shell?
a) 1
b) 2
c) 3
d) 4

A

3

164
Q

Hybridization of atomic orbitals occurs when:
a) Electrons are gained or lost
b) Electrons are shared between atoms
c) Atomic orbitals overlap
d) Electron shells are rearranged

A

Atomic orbitals overlap

165
Q

Valency bond theory explains chemical bonding in terms of:
a) Electron configuration
b) Atomic mass
c) Hybrid orbitals
d) Atomic number

A

Electron configuration

166
Q

Ethane (C2H6) consists of:
a) Two carbon atoms bonded by a triple bond
b) Two carbon atoms bonded by a double bond
c) Two carbon atoms bonded by a single bond
d) Two carbon atoms bonded by a quadruple bond

A

Two carbon atoms bonded by a single bond

167
Q

Ethylene (C2H4) is an example of a(n):
a) Alkane
b) Alkene
c) Alkyne
d) Aromatic compound

A

Alkene

168
Q

Acetylene (C2H2) is an example of a(n):
a) Alkane
b) Alkene
c) Alkyne
d) Aromatic compound

A

Alkyne

169
Q

According to molecular orbital theory, the bonding molecular orbital is formed by:
a) Constructive interference of atomic orbitals
b) Destructive interference of atomic orbitals
c) Combination of s and p orbitals
d) Combination of different hybrid orbitals

A

Constructive interference of atomic orbitals

170
Q

Enantiomers are molecules that:
a) Have the same molecular formula but differ in connectivity
b) Have the same molecular formula and identical three-dimensional structures
c) Are mirror images of each other and cannot be superimposed
d) Have the same chemical properties but different physical properties

A

Are mirror images of each other and cannot be superimposed

171
Q

Stereochemistry is the study of the ________________ and ________________ of molecules.

A

Three-dimensional or spatial; arrangement or configuration

172
Q

Meso compounds are optically inactive due to the presence of a ________________ plane of symmetry.

A

Horizontal or vertical

173
Q

Clinical importance of stereochemistry is evident in drug development as enantiomers may exhibit different ________________ and ________________ in the body.

A

Pharmacological or therapeutic; effects or activities

174
Q

Alkanes are hydrocarbons that contain only single bonds. True or false?

A

True

175
Q

Alkenes are hydrocarbons that contain at least one double bond. True or false?

A

True

176
Q

Newborn jaundice is a condition caused by the buildup of bilirubin in the blood. True or false?

A

True

177
Q

Hybridization of atomic orbitals is a random process. True or false?

A

False

178
Q

Ethylene is an example of a cyclic hydrocarbon. True or false?

A

False

179
Q

Valence bond theory is also known as electron cloud theory. True or false?

A

False

180
Q

Meso compounds are optically active due to their mirror-image symmetry. True or false?

A

False

181
Q

Organic chemistry is the branch of chemistry that deals with the study of:
a) Carbon compounds only
b) All elements and their compounds
c) Inorganic compounds only
d) Noble gases

A

Carbon compounds only

182
Q

Who is credited with the discovery of benzene’s structure?
a) Friedrich Wöhler
b) Kekulé
c) Linus Pauling
d) Robert Boyle

A

Kekulé

183
Q

How many valence electrons does carbon have?
a) 2
b) 4
c) 6
d) 8

A

4

184
Q

The atomic orbitals in the second electron shell are denoted by the letters:
a) s and p
b) p and d
c) d and f
d) f and g

A

p and d

185
Q

Hybridization of atomic orbitals is necessary to explain the:
a) Formation of covalent bonds
b) Formation of ionic bonds
c) Formation of metallic bonds
d) Formation of hydrogen bonds

A

Formation of covalent bonds

186
Q

Ethane (C2H6) is an example of a(n):
a) Alkane
b) Alkene
c) Alkyne
d) Aromatic compound

A

Alkane

187
Q

The molecular formula of ethylene is:
a) C2H4
b) C2H2
c) C2H6
d) C3H8

A

C2H4

188
Q

Acetylene (C2H2) is an example of a(n):
a) Alkane
b) Alkene
c) Alkyne
d) Aromatic compound

A

Alkyne

189
Q

According to molecular orbital theory, the bonding molecular orbital is formed by the:
a) Addition of atomic orbitals
b) Subtraction of atomic orbitals
c) Overlap of atomic orbitals
d) Repulsion of atomic orbitals

A

Overlap of atomic orbitals

190
Q

Stereochemistry is the study of the ________________ and ________________ of molecules.

A

Three-dimensional or spatial; arrangement or configuration

191
Q

Enantiomers have ________________ physical properties but differ in their interaction with ________________ light.

A

Similar or identical; polarized

192
Q

Hybridization of atomic orbitals can result in the formation of sp3, sp2, and sp hybrid orbitals. True or false?

A

True

193
Q

Molecular orbital theory predicts the behavior of electrons in molecules based on the combination of atomic orbitals. True or false?

A

True

194
Q

Which of the following is an example of a chiral molecule?
a) Ethane
b) Benzene
c) Propane
d) Lactic acid

A

Lactic acid

195
Q

What is the hybridization of the carbon atom in ethyne (acetylene)?
a) sp
b) sp2
c) sp3
d) dsp2

A

sp

196
Q

Which of the following statements about enantiomers is true?
a) They have identical physical properties.
b) They rotate plane-polarized light in opposite directions.
c) They cannot exist in the same solution.
d) They have different molecular formulas.

A

They rotate plane-polarized light in opposite directions.

197
Q

A meso compound possesses ________________ symmetry elements, resulting in its optical inactivity.

A

Internal or plane or center

198
Q

In molecular orbital theory, the ________________ molecular orbital is formed by constructive interference of atomic orbitals, while the ________________ molecular orbital is formed by destructive interference of atomic orbitals.

A

Bonding or sigma or pi; antibonding or sigma* or pi*

199
Q

Valence bond theory focuses on the overlap of atomic orbitals to form chemical bonds. True or false?

A

True

200
Q

A molecule can exhibit chirality even if it contains a plane of symmetry. True or false?

A

False

Committee Exam 4 (35 decks)

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