Question 1

During the contraction phase of a muscle twitch,

Accepted Answer

A)  acetylcholine stimulates the pre-synaptic terminal. 
B)  Na+ diffuse into the muscle fiber. 
C)  actin-myosin cross-bridges form. 
D)  Ca2+ are transported back to the sarcoplasmic reticulum. 
E)  the action potential travels down the T tubule. 
A)  acetylcholine stimulates the pre-synaptic terminal. 
B)  Na+ diffuse into the muscle fiber. 
C)  actin-myosin cross-bridges form. 
D)  Ca2+ are transported back to the sarcoplasmic reticulum. 
E)  the action potential travels down the T tubule.

Question 2

Inflammation of the fibrous connective tissue resulting in stiffness and soreness is

Accepted Answer

A)  cramps. 
B)  fibrositis. 
C)  fibrosis. 
D)  muscular dystrophy. 
E)  paralysis. 
A)  cramps. 
B)  fibrositis. 
C)  fibrosis. 
D)  muscular dystrophy. 
E)  paralysis.

Question 3

An antibody test on smooth muscle reveals fewer dense bodies and intermediate filaments in a patient with a colon disorder. What is the purpose of these structures?

Accepted Answer

A)  They allow for rapidly developing action potentials in smooth muscle cells. 
B)  They are shallow invaginations of plasma membrane. 
C)  They maintain relatively constant tension in smooth muscle for a period of time. 
D)  They are part of the intracellular cytoskeleton. 
E)  They act as enzymes that remove phosphate from myosin. 
A)  They allow for rapidly developing action potentials in smooth muscle cells. 
B)  They are shallow invaginations of plasma membrane. 
C)  They maintain relatively constant tension in smooth muscle for a period of time. 
D)  They are part of the intracellular cytoskeleton. 
E)  They act as enzymes that remove phosphate from myosin.

Question 4

Michael Jordan was arguably the best player in professional basketball history. Scientifically, one would expect him to have highly developed ________ fibers.

Accepted Answer

A)  red 
B)  white 
C)  intermediate 
D)  fast twitch 
E)  slow oxidative 
A)  red 
B)  white 
C)  intermediate 
D)  fast twitch 
E)  slow oxidative

Question 5

A toxin released by the anaerobic bacterium Clostridium botulinum causes the food-borne illness known as botulism, which inhibits the release of ACh at the neuromuscular junction. What effect does this have on a person infected with the bacterium?

Accepted Answer

A)  It causes flaccid paralysis, and if it affects the respiratory muscles, can result in death. 
B)  It disrupts the balance between ACh and acetylcholinesterase, leading to spastic contractions. 
C)  The brain compensates by producing more ACh, limiting the illness to only a few hours. 
D)  The jaws are most affected, and it results in "lockjaw." 
E)  Problems only result when the individual has low immunity. 
A)  It causes flaccid paralysis, and if it affects the respiratory muscles, can result in death. 
B)  It disrupts the balance between ACh and acetylcholinesterase, leading to spastic contractions. 
C)  The brain compensates by producing more ACh, limiting the illness to only a few hours. 
D)  The jaws are most affected, and it results in "lockjaw." 
E)  Problems only result when the individual has low immunity.

Question 6

-The figure illustrates a detailed drawing of the neuromuscular junction. What does "D" represent?

Accepted Answer

A)  Synaptic vesicles 
B)  Synaptic cleft 
C)  Sarcolemma 
D)  Presynaptic terminal 
E)  Postsynaptic membrane 
A)  Synaptic vesicles 
B)  Synaptic cleft 
C)  Sarcolemma 
D)  Presynaptic terminal 
E)  Postsynaptic membrane

Question 7

Anabolic steroids can do all of the following except

Accepted Answer

A)  increase muscle size and strength. 
B)  cause testicular atrophy. 
C)  cause cardiovascular disease. 
D)  increase the number of muscle fibers. 
E)  increase total muscle mass. 
A)  increase muscle size and strength. 
B)  cause testicular atrophy. 
C)  cause cardiovascular disease. 
D)  increase the number of muscle fibers. 
E)  increase total muscle mass.

Question 8

Whole muscles can respond in a graded fashion to stimuli by varying

Accepted Answer

A)  the force of contraction of individual muscle fibers. 
B)  the number of motor units recruited. 
C)  the amplitude of the action potential. 
D)  the frequency of stimulus. 
E)  thresholds. 
A)  the force of contraction of individual muscle fibers. 
B)  the number of motor units recruited. 
C)  the amplitude of the action potential. 
D)  the frequency of stimulus. 
E)  thresholds.

Question 9

Which fibers are primarily responsible for producing lactate?

Accepted Answer

A)  Slow fibers 
B)  Type IIA fast fibers 
C)  Type IIB fast fibers 
D)  Type I slow-twitch fibers 
E)  Red fibers 
A)  Slow fibers 
B)  Type IIA fast fibers 
C)  Type IIB fast fibers 
D)  Type I slow-twitch fibers 
E)  Red fibers

Question 10

Consider a chemical that blocks the action of acetylcholinesterase. What effect does this have on muscles?

Accepted Answer

A)  It would cause paralysis. 
B)  It would cause action potentials to be inhibited, thereby rendering the muscle useless. 
C)  The body would increase its production of acetylcholine to compensate. 
D)  The axons of the motor neurons would atrophy, and the muscle would weaken. 
E)  The muscle would have no way to relax, and spastic contractions would result. 
A)  It would cause paralysis. 
B)  It would cause action potentials to be inhibited, thereby rendering the muscle useless. 
C)  The body would increase its production of acetylcholine to compensate. 
D)  The axons of the motor neurons would atrophy, and the muscle would weaken. 
E)  The muscle would have no way to relax, and spastic contractions would result.

Question 11

Whales are air-breathing aquatic mammals, and some species can remain underwater for long periods of time. Which type of skeletal muscle fibers are most likely dominant in these deep diving whales?

Accepted Answer

A)  Slow fibers 
B)  Fast (type IIa) fibers 
C)  Fast (IIb) fibers 
D)  White fibers 
A)  Slow fibers 
B)  Fast (type IIa) fibers 
C)  Fast (IIb) fibers 
D)  White fibers

Question 12

Which of the following statements does not accurately describe factors that determine the amount of force generated during a muscle contraction?

Accepted Answer

A)  The number of cross-bridges that can form is higher in a short muscle fiber compared to longer fibers. 
B)  Muscle fibers that have larger diameters have more myofibrils and therefore can form more cross-bridges. 
C)  Increasing stimulation of a muscle fiber results in increased formation of cross-bridges. 
D)  Muscle fibers that are stretched to the optimal length will provide higher numbers of cross-bridges. 
A)  The number of cross-bridges that can form is higher in a short muscle fiber compared to longer fibers. 
B)  Muscle fibers that have larger diameters have more myofibrils and therefore can form more cross-bridges. 
C)  Increasing stimulation of a muscle fiber results in increased formation of cross-bridges. 
D)  Muscle fibers that are stretched to the optimal length will provide higher numbers of cross-bridges.

Question 13

Which of the following is not an important function of calcium ions in skeletal muscle activity?

Accepted Answer

A)  Depolarization of the sarcolemma 
B)  Release of acetylcholine from the presynaptic terminal 
C)  Exposure of the active sites on G actin 
D)  All of these are important functions of calcium ions in skeletal muscle contraction. 
A)  Depolarization of the sarcolemma 
B)  Release of acetylcholine from the presynaptic terminal 
C)  Exposure of the active sites on G actin 
D)  All of these are important functions of calcium ions in skeletal muscle contraction.

Question 14

The H zone

Accepted Answer

A)  contains only myosin myofilaments. 
B)  contains only actin myofilaments. 
C)  contains both myosin and actin myofilaments. 
A)  contains only myosin myofilaments. 
B)  contains only actin myofilaments. 
C)  contains both myosin and actin myofilaments.

Question 15

Which of the following causes an unequal ion concentration across the resting plasma membrane?

Accepted Answer

A)  The functioning of the sodium-chloride pump 
B)  Negatively charged proteins not readily diffusing across the plasma membrane 
C)  The attraction of chloride ions to other intracellular anions 
D)  The repulsion of potassium ions by the intracellular anions 
E)  The attraction of sodium ions to chloride ions 
A)  The functioning of the sodium-chloride pump 
B)  Negatively charged proteins not readily diffusing across the plasma membrane 
C)  The attraction of chloride ions to other intracellular anions 
D)  The repulsion of potassium ions by the intracellular anions 
E)  The attraction of sodium ions to chloride ions

Question 16

Which type of muscle tissue causes vasoconstriction?

Accepted Answer

A)  Skeletal muscle 
B)  Smooth muscle 
C)  Cardiac muscle 
A)  Skeletal muscle 
B)  Smooth muscle 
C)  Cardiac muscle

Question 17

Randy is participating in a strong man competition and is required to pull a yacht as far as he can. Which type of chemical process will his skeletal muscles rely on during this competition?

Accepted Answer

A)  Anaerobic respiration 
B)  Aerobic respiration 
C)  Both anaerobic respiration and aerobic respiration are correct. 
A)  Anaerobic respiration 
B)  Aerobic respiration 
C)  Both anaerobic respiration and aerobic respiration are correct.

Question 18

Muscles exhibit the property of excitability. This means that the muscle

Accepted Answer

A)  shortens its length. 
B)  recoils to its original resting length. 
C)  stretches beyond its normal length. 
D)  responds to stimulation by the nervous system. 
E)  excites itself. 
A)  shortens its length. 
B)  recoils to its original resting length. 
C)  stretches beyond its normal length. 
D)  responds to stimulation by the nervous system. 
E)  excites itself.

Question 19

The electrical properties of cells are the result of

Accepted Answer

A)  ion concentration differences across the plasma membrane. 
B)  receptor sites that are present on the plasma membrane. 
C)  phosphorylation reactions within the cytoplasm. 
D)  phospholipids in the plasma membrane. 
E)  None of these choices are correct. 
A)  ion concentration differences across the plasma membrane. 
B)  receptor sites that are present on the plasma membrane. 
C)  phosphorylation reactions within the cytoplasm. 
D)  phospholipids in the plasma membrane. 
E)  None of these choices are correct.

Question 20

In which of the following situations does a resting membrane potential exist?

Accepted Answer

A)  A relaxed muscle fiber 
B)  A conducting neuron 
C)  A stimulated sensory receptor in the skin 
D)  A contracting cardiac muscle cell 
E)  The eye seeing an image 
A)  A relaxed muscle fiber 
B)  A conducting neuron 
C)  A stimulated sensory receptor in the skin 
D)  A contracting cardiac muscle cell 
E)  The eye seeing an image

Exam 9: Muscular System: Histology and Physiology

During the contraction phase of a muscle twitch,

Inflammation of the fibrous connective tissue resulting in stiffness and soreness is

An antibody test on smooth muscle reveals fewer dense bodies and intermediate filaments in a patient with a colon disorder. What is the purpose of these structures?

Michael Jordan was arguably the best player in professional basketball history. Scientifically, one would expect him to have highly developed ________ fibers.

A toxin released by the anaerobic bacterium Clostridium botulinum causes the food-borne illness known as botulism, which inhibits the release of ACh at the neuromuscular junction. What effect does this have on a person infected with the bacterium?

-The figure illustrates a detailed drawing of the neuromuscular junction. What does "D" represent?

Anabolic steroids can do all of the following except

Whole muscles can respond in a graded fashion to stimuli by varying

Which fibers are primarily responsible for producing lactate?

Consider a chemical that blocks the action of acetylcholinesterase. What effect does this have on muscles?

Whales are air-breathing aquatic mammals, and some species can remain underwater for long periods of time. Which type of skeletal muscle fibers are most likely dominant in these deep diving whales?

Which of the following statements does not accurately describe factors that determine the amount of force generated during a muscle contraction?

Which of the following is not an important function of calcium ions in skeletal muscle activity?

The H zone

Which of the following causes an unequal ion concentration across the resting plasma membrane?

Which type of muscle tissue causes vasoconstriction?

Randy is participating in a strong man competition and is required to pull a yacht as far as he can. Which type of chemical process will his skeletal muscles rely on during this competition?

Muscles exhibit the property of excitability. This means that the muscle

The electrical properties of cells are the result of

In which of the following situations does a resting membrane potential exist?

The Human Organism

The Chemical Basis of Life

Cell Biology

Tissues

Integumentary System

Skeletal System: Bones and Bone Tissue

Skeletal System: Gross Anatomy

Joint and Movement

Muscular System: Gross Anatomy

Functional Organization of Nervous Tissue

Spinal Cord and Spinal Nerves

Brain and Cranial Nerves

Integration of Nervous System Functions

The Special Senses

Autonomic Nervous System

Functional Organization of the Endocrine System

Endocrine Glands

Cardiovascular System: Blood

Cardiovascular System: the Heart

Cardiovascular System: Blood Vessels and Circulation

Lymphatic System and Immunity

Respiratory System

Digestive System

Nutrition, Metabolism, and Temperature Regulation

Urinary System

Water, Electrolyte, and Acid-Base Balance

Reproductive System

Development, Growth, Aging, and Genetics

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