Question 1

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 2

-What does "D" represent on the diagram?

Accepted Answer

A)  threshold 
B)  depolarization 
C)  depolarization phase of action potential 
D)  repolarization phase of action potential 
A)  threshold 
B)  depolarization 
C)  depolarization phase of action potential 
D)  repolarization phase of action potential

Question 3

After contraction has occurred, the calcium is

Accepted Answer

A)  destroyed by cholinesterase. 
B)  chemically bound to the cross bridges. 
C)  secreted by the Golgi apparatus to the outside of the cell. 
D)  released from troponin. 
E)  returned to the sarcolemma. 
A)  destroyed by cholinesterase. 
B)  chemically bound to the cross bridges. 
C)  secreted by the Golgi apparatus to the outside of the cell. 
D)  released from troponin. 
E)  returned to the sarcolemma.

Question 4

Which of the following statements concerning fast-twitch muscle fibers is true?

Accepted Answer

A)  They split ATP rapidly. 
B)  They have large deposits of myoglobin. 
C)  They are well adapted to aerobic metabolism. 
D)  They have a well-developed blood supply. 
E)  They have many mitochondria. 
A)  They split ATP rapidly. 
B)  They have large deposits of myoglobin. 
C)  They are well adapted to aerobic metabolism. 
D)  They have a well-developed blood supply. 
E)  They have many mitochondria.

Question 5

Incomplete tetanus

Accepted Answer

A)  is the time during which the tissue cannot respond again. 
B)  results in complete and incomplete tetanus. 
C)  is the condition in which the muscle fiber only partially relaxes between contractions. 
D)  is the condition in which stimuli occur so rapidly that there are no intervening relaxations. 
E)  is the constant tension produced by muscles for long periods of time. 
A)  is the time during which the tissue cannot respond again. 
B)  results in complete and incomplete tetanus. 
C)  is the condition in which the muscle fiber only partially relaxes between contractions. 
D)  is the condition in which stimuli occur so rapidly that there are no intervening relaxations. 
E)  is the constant tension produced by muscles for long periods of time.

Question 6

A child ingested an organophosphate poison used to kill insects. Soon the child's muscles began spastic contractions. Predict what occurred at the synaptic cleft.

Accepted Answer

A)  decreased release of acetylcholine from presynaptic neurons 
B)  increased accumulation of acetylcholine in the synapse 
C)  the poison binds to acetylcholine receptors and stimulates them 
D)  increased breakdown of acetylcholine in the synaptic cleft 
E)  Both increased accumulation of acetylcholine in the synapse and increased breakdown of acetylcholine in the synaptic cleft. 
A)  decreased release of acetylcholine from presynaptic neurons 
B)  increased accumulation of acetylcholine in the synapse 
C)  the poison binds to acetylcholine receptors and stimulates them 
D)  increased breakdown of acetylcholine in the synaptic cleft 
E)  Both increased accumulation of acetylcholine in the synapse and increased breakdown of acetylcholine in the synaptic cleft.

Question 7

A drug that interferes with the active transport of calcium ions from the sarcoplasm back into the sarcoplasmic reticulum would result in

Accepted Answer

A)  relaxation of the muscle fiber. 
B)  contraction with no relaxation. 
C)  muscle hypertrophy. 
D)  fibrosis of the muscle. 
E)  an imbalance of blood calcium. 
A)  relaxation of the muscle fiber. 
B)  contraction with no relaxation. 
C)  muscle hypertrophy. 
D)  fibrosis of the muscle. 
E)  an imbalance of blood calcium.

Question 8

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

Question 9

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 10

Visceral smooth muscle

Accepted Answer

A)  may contain groups of cells that function as an independent unit. 
B)  occurs in sheets and exhibits numerous gap junctions. 
C)  contracts only when stimulated. 
D)  does not function as a unit. 
E)  All of these choices are correct. 
A)  may contain groups of cells that function as an independent unit. 
B)  occurs in sheets and exhibits numerous gap junctions. 
C)  contracts only when stimulated. 
D)  does not function as a unit. 
E)  All of these choices are correct.

Question 11

Aerobic exercise

Accepted Answer

A)  increases vascularity of muscle. 
B)  develops fatigue-resistant fast-twitch fibers. 
C)  can increase the efficiency of slow-twitch fibers. 
D)  can increase the number of mitochondria in muscle cells. 
E)  All of these choices are correct. 
A)  increases vascularity of muscle. 
B)  develops fatigue-resistant fast-twitch fibers. 
C)  can increase the efficiency of slow-twitch fibers. 
D)  can increase the number of mitochondria in muscle cells. 
E)  All of these choices are correct.

Question 12

Which of the following is true during the resting membrane potential?

Accepted Answer

A)  Sodium ion concentration is greater inside cells. 
B)  Negatively charged proteins are more concentrated outside the cell. 
C)  A greater concentration of calcium ions is found inside the cell. 
D)  Potassium is concentrated primarily inside the cell. 
E)  None of these choices reflect what occurs during the resting membrane potential. 
A)  Sodium ion concentration is greater inside cells. 
B)  Negatively charged proteins are more concentrated outside the cell. 
C)  A greater concentration of calcium ions is found inside the cell. 
D)  Potassium is concentrated primarily inside the cell. 
E)  None of these choices reflect what occurs during the resting membrane potential.

Question 13

Why does muscle activity affect the temperature of the body?

Accepted Answer

A)  The rate of chemical reactions increases in muscle fibers during contraction, so the rate of heat production also increases. 
B)  Muscle contraction generates pyrogens which reset the body's internal thermostat to a higher temperature. 
C)  Muscle activity directs more warm blood to the muscles away from the central core causing a cooling effect on your internal organs. 
D)  Increased muscle activity causes a rise in adipose stores which increases the insulation value of the body. 
A)  The rate of chemical reactions increases in muscle fibers during contraction, so the rate of heat production also increases. 
B)  Muscle contraction generates pyrogens which reset the body's internal thermostat to a higher temperature. 
C)  Muscle activity directs more warm blood to the muscles away from the central core causing a cooling effect on your internal organs. 
D)  Increased muscle activity causes a rise in adipose stores which increases the insulation value of the body.

Question 14

Which type of muscle tissue would cause flexion and extension of the arm?

Accepted Answer

A)  skeletal muscle 
B)  smooth muscle 
C)  cardiac muscle 
A)  skeletal muscle 
B)  smooth muscle 
C)  cardiac muscle

Question 15

Which of the following situations occurs in electrically excitable cells?

Accepted Answer

A)  When Na+ ion channels open, K+ ion channels close. 
B)  The sodium-potassium pump moves sodium into the cell. 
C)  Depolarization causes voltage-gated sodium ion channels to open. 
D)  Sodium ion channels are opened by high extracellular calcium levels. 
E)  The opening and closing of ligand-gated channels cause depolarization. 
A)  When Na+ ion channels open, K+ ion channels close. 
B)  The sodium-potassium pump moves sodium into the cell. 
C)  Depolarization causes voltage-gated sodium ion channels to open. 
D)  Sodium ion channels are opened by high extracellular calcium levels. 
E)  The opening and closing of ligand-gated channels cause depolarization.

Question 16

Smooth muscle and cardiac muscle are similar in that they both

Accepted Answer

A)  are under involuntary control. 
B)  are striated. 
C)  are widely distributed in the body. 
D)  have multiple nuclei. 
E)  are under voluntary control. 
A)  are under involuntary control. 
B)  are striated. 
C)  are widely distributed in the body. 
D)  have multiple nuclei. 
E)  are under voluntary control.

Question 17

Alex is participating in a 50 meter dash. Predict the most important chemical process his muscles will rely on during this race.

Accepted Answer

A)  aerobic respiration. 
B)  anaerobic respiration. 
C)  creatine phosphate breakdown. 
D)  nuclear reactions. 
E)  both anaerobic respiration and creatine phosphate breakdown. 
A)  aerobic respiration. 
B)  anaerobic respiration. 
C)  creatine phosphate breakdown. 
D)  nuclear reactions. 
E)  both anaerobic respiration and creatine phosphate breakdown.

Question 18

A cancer patient is told by their physician that their colon is lacking smooth muscle tone. What does this mean?

Accepted Answer

A)  The colon is developing action potentials too rapidly. 
B)  The colon has too many shallow invaginations of cell membranes. 
C)  The colon is unable to maintain constant tension for sustained periods of time. 
D)  The intracellular cytoskeleton is overactive. 
A)  The colon is developing action potentials too rapidly. 
B)  The colon has too many shallow invaginations of cell membranes. 
C)  The colon is unable to maintain constant tension for sustained periods of time. 
D)  The intracellular cytoskeleton is overactive.

Question 19

What is the role of pacemaker cells?

Accepted Answer

A)  can rapidly develop action potentials 
B)  shallow invaginations of cell membrane 
C)  relatively constant tension maintained for a period of time 
D)  intracellular cytoskeleton 
E)  enzyme that removes phosphate from myosin 
A)  can rapidly develop action potentials 
B)  shallow invaginations of cell membrane 
C)  relatively constant tension maintained for a period of time 
D)  intracellular cytoskeleton 
E)  enzyme that removes phosphate from myosin

Question 20

Which of the following is NOT a function of skeletal muscle?

Accepted Answer

A)  body movement 
B)  maintenance of posture 
C)  respiration 
D)  constriction of organs 
E)  production of heat 
A)  body movement 
B)  maintenance of posture 
C)  respiration 
D)  constriction of organs 
E)  production of heat

Exam 9: Muscular System: Histology and Physiology

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

-What does "D" represent on the diagram?

After contraction has occurred, the calcium is

Which of the following statements concerning fast-twitch muscle fibers is true?

Incomplete tetanus

A child ingested an organophosphate poison used to kill insects. Soon the child's muscles began spastic contractions. Predict what occurred at the synaptic cleft.

A drug that interferes with the active transport of calcium ions from the sarcoplasm back into the sarcoplasmic reticulum would result in

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?

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

Visceral smooth muscle

Aerobic exercise

Which of the following is true during the resting membrane potential?

Why does muscle activity affect the temperature of the body?

Which type of muscle tissue would cause flexion and extension of the arm?

Which of the following situations occurs in electrically excitable cells?

Smooth muscle and cardiac muscle are similar in that they both

Alex is participating in a 50 meter dash. Predict the most important chemical process his muscles will rely on during this race.

A cancer patient is told by their physician that their colon is lacking smooth muscle tone. What does this mean?

What is the role of pacemaker cells?

Which of the following is NOT a function of skeletal muscle?

The Human Organism

The Chemical Basis of Life

Cell Biology

Tissues

Integumentary System

Skeletal System: Bones and Bone Tissue

Skeletal System: Gross Anatomy

Joints 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-Based Balance

Reproductive System

Development, Growth, Aging, and Genetics

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