Question 1

In smooth muscle, most of the calcium needed for muscle contraction

Accepted Answer

A)  is in the dense bodies. 
B)  enters from extracellular fluid. 
C)  is attached to the intermediate filaments. 
D)  must be activated by myosin kinase. 
E)  is stored in the sarcoplasmic reticulum. 
A)  is in the dense bodies. 
B)  enters from extracellular fluid. 
C)  is attached to the intermediate filaments. 
D)  must be activated by myosin kinase. 
E)  is stored in the sarcoplasmic reticulum.

Question 2

-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 3

-What does "C" represent on the diagram?

Accepted Answer

A)  myosin myofilament 
B)  actin myofilament 
C)  sarcomere 
D)  Z disk 
E)  cross-bridge 
A)  myosin myofilament 
B)  actin myofilament 
C)  sarcomere 
D)  Z disk 
E)  cross-bridge

Question 4

Acetylcholine is released from the presynaptic terminal by the process of

Accepted Answer

A)  exocytosis. 
B)  diffusion. 
C)  phagocytosis. 
D)  active transport. 
E)  endocytosis. 
A)  exocytosis. 
B)  diffusion. 
C)  phagocytosis. 
D)  active transport. 
E)  endocytosis.

Question 5

Which of the following actions is caused by contraction of skeletal muscle?

Accepted Answer

A)  contraction of the heart 
B)  moving your feet in walking 
C)  movement of food through the digestive tract 
D)  emptying of the urinary bladder 
E)  vasoconstriction 
A)  contraction of the heart 
B)  moving your feet in walking 
C)  movement of food through the digestive tract 
D)  emptying of the urinary bladder 
E)  vasoconstriction

Question 6

The active sites to which cross-bridges attach are found on the

Accepted Answer

A)  sarcoplasmic reticulum. 
B)  actin myofilaments. 
C)  Z disks. 
D)  T tubules. 
E)  myosin myofilaments. 
A)  sarcoplasmic reticulum. 
B)  actin myofilaments. 
C)  Z disks. 
D)  T tubules. 
E)  myosin myofilaments.

Question 7

What are caveolae?

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 8

-What does "C" 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 9

The type of muscle fatigue known as "psychological fatigue" is the result of

Accepted Answer

A)  depleted ATP reserves. 
B)  increased calcium ion concentration in the sarcoplasm. 
C)  decreased levels of acetylcholine. 
D)  the emotional state of an individual. 
E)  None of these choices is correct. 
A)  depleted ATP reserves. 
B)  increased calcium ion concentration in the sarcoplasm. 
C)  decreased levels of acetylcholine. 
D)  the emotional state of an individual. 
E)  None of these choices is correct.

Question 10

An isometric contraction is described as

Accepted Answer

A)  action potential frequency is high enough that no relaxation of muscle fibers occurs. 
B)  a muscle produces constant tension during contraction. 
C)  a muscle produces an increasing tension as the length remains constant. 
D)  a muscle produces increasing tension as it shortens. 
E)  a muscle produces tension, but the length of the muscle is increasing. 
A)  action potential frequency is high enough that no relaxation of muscle fibers occurs. 
B)  a muscle produces constant tension during contraction. 
C)  a muscle produces an increasing tension as the length remains constant. 
D)  a muscle produces increasing tension as it shortens. 
E)  a muscle produces tension, but the length of the muscle is increasing.

Question 11

The region of the sarcomere that contains both actin and myosin myofilaments is called the

Accepted Answer

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

Question 12

Which type of muscle tissue has cells that branch?

Accepted Answer

A)  skeletal muscle 
B)  smooth muscle 
C)  cardiac muscle 
D)  both skeletal and cardiac muscle 
E)  both cardiac and smooth muscle 
A)  skeletal muscle 
B)  smooth muscle 
C)  cardiac muscle 
D)  both skeletal and cardiac muscle 
E)  both cardiac and smooth muscle

Question 13

Which of the following events occurs during the lag phase of a muscle twitch?

Accepted Answer

A)  Muscle fibers shorten. 
B)  Cross-bridges form, move, release, and reform many times. 
C)  The action potential is propagated from presynaptic to postsynaptic membrane. 
D)  Calcium is pumped back into the sarcoplasmic reticulum. 
E)  All of these events occur in the lag phase. 
A)  Muscle fibers shorten. 
B)  Cross-bridges form, move, release, and reform many times. 
C)  The action potential is propagated from presynaptic to postsynaptic membrane. 
D)  Calcium is pumped back into the sarcoplasmic reticulum. 
E)  All of these events occur in the lag phase.

Question 14

Actin myofilaments

Accepted Answer

A)  resemble bundles of minute golf clubs. 
B)  contain both myosin and tropomyosin. 
C)  are held in place by the M line. 
D)  contain strands of fibrous actin. 
E)  are the thickest proteins in muscle. 
A)  resemble bundles of minute golf clubs. 
B)  contain both myosin and tropomyosin. 
C)  are held in place by the M line. 
D)  contain strands of fibrous actin. 
E)  are the thickest proteins in muscle.

Question 15

-What does "A" 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 16

Which of the following is part of a thin myofilament?

Accepted Answer

A)  ATP-binding site 
B)  globular (G) actin 
C)  calcium 
D)  myosin 
E)  sarcolemma 
A)  ATP-binding site 
B)  globular (G) actin 
C)  calcium 
D)  myosin 
E)  sarcolemma

Question 17

Which of the following is NOT true of the latch state of smooth muscle contraction?

Accepted Answer

A)  Myosin phosphatase removes the phosphate group from myosin. 
B)  It explains why smooth muscle can sustain tension for long periods of time. 
C)  It occurs when the phosphate is removed while the cross-bridges are attached to actin. 
D)  It occurs when the phosphate is removed while the cross-bridges are not attached to actin. 
E)  It allows contraction without a large energy expenditure. 
A)  Myosin phosphatase removes the phosphate group from myosin. 
B)  It explains why smooth muscle can sustain tension for long periods of time. 
C)  It occurs when the phosphate is removed while the cross-bridges are attached to actin. 
D)  It occurs when the phosphate is removed while the cross-bridges are not attached to actin. 
E)  It allows contraction without a large energy expenditure.

Question 18

Which of the following is true about skeletal muscle?

Accepted Answer

A)  Sensory neurons stimulate muscles to contract. 
B)  There are very few blood vessels in skeletal muscle. 
C)  Every muscle fiber receives a branch of an axon from the nerve. 
D)  There are very few nerve fibers in a muscle. 
E)  All of these are true. 
A)  Sensory neurons stimulate muscles to contract. 
B)  There are very few blood vessels in skeletal muscle. 
C)  Every muscle fiber receives a branch of an axon from the nerve. 
D)  There are very few nerve fibers in a muscle. 
E)  All of these are true.

Question 19

Rigor mortis occurs after death because

Accepted Answer

A)  cross-bridges form but can't release. 
B)  calcium is actively transported back to the sarcoplasmic reticulum. 
C)  anaerobic respiration is occurring. 
D)  myosin levels decline at death. 
E)  cross-bridges never form. 
A)  cross-bridges form but can't release. 
B)  calcium is actively transported back to the sarcoplasmic reticulum. 
C)  anaerobic respiration is occurring. 
D)  myosin levels decline at death. 
E)  cross-bridges never form.

Question 20

Movements of the body are usually smooth and occur at differing rates because

Accepted Answer

A)  they are a mixture of isotonic and isometric contractions. 
B)  motor units contract out of phase at their own particular rates. 
C)  most muscle contractions closely resemble individual muscle twitches. 
D)  muscles of different sizes contract at different rates. 
E)  of the all or none principle. 
A)  they are a mixture of isotonic and isometric contractions. 
B)  motor units contract out of phase at their own particular rates. 
C)  most muscle contractions closely resemble individual muscle twitches. 
D)  muscles of different sizes contract at different rates. 
E)  of the all or none principle.

Exam 9: Muscular System: Histology and Physiology

In smooth muscle, most of the calcium needed for muscle contraction

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

-What does "C" represent on the diagram?

Acetylcholine is released from the presynaptic terminal by the process of

Which of the following actions is caused by contraction of skeletal muscle?

The active sites to which cross-bridges attach are found on the

What are caveolae?

-What does "C" represent on the diagram?

The type of muscle fatigue known as "psychological fatigue" is the result of

An isometric contraction is described as

The region of the sarcomere that contains both actin and myosin myofilaments is called the

Which type of muscle tissue has cells that branch?

Which of the following events occurs during the lag phase of a muscle twitch?

Actin myofilaments

-What does "A" represent on the diagram?

Which of the following is part of a thin myofilament?

Which of the following is NOT true of the latch state of smooth muscle contraction?

Which of the following is true about skeletal muscle?

Rigor mortis occurs after death because

Movements of the body are usually smooth and occur at differing rates because

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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