Question 1

Treppe

Accepted Answer

A)  can contribute to improved muscle efficiency. 
B)  may be due to an increase in the level of calcium ions around the myofibril. 
C)  is an example of a graded response. 
D)  is achieved during warm-up exercises. 
E)  All of these choices are correct. 
A)  can contribute to improved muscle efficiency. 
B)  may be due to an increase in the level of calcium ions around the myofibril. 
C)  is an example of a graded response. 
D)  is achieved during warm-up exercises. 
E)  All of these choices are correct.

Question 2

-The figure illustrates a detailed drawing of the neuromuscular junction. What does "C" 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

Which of the following statements concerning types of muscle contractions is false?

Accepted Answer

A)  In isometric contractions, the amount of tension produced by the muscle is constant. 
B)  In isotonic contractions, the muscle fibers shorten. 
C)  The contractile processes in isometric and isotonic contractions are the same. 
D)  Most skeletal muscle contractions are a combination of isometric and isotonic contractions. 
E)  In isotonic contractions, the amount of tension produced by the muscle fibers is constant during the contraction. 
A)  In isometric contractions, the amount of tension produced by the muscle is constant. 
B)  In isotonic contractions, the muscle fibers shorten. 
C)  The contractile processes in isometric and isotonic contractions are the same. 
D)  Most skeletal muscle contractions are a combination of isometric and isotonic contractions. 
E)  In isotonic contractions, the amount of tension produced by the muscle fibers is constant during the contraction.

Question 4

Which type of muscle tissue is autorhythmic?

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 5

You are hired to work in a laboratory to measure the rate of human muscle contraction. Which of the following might decrease in quantity in muscle cells undergoing contractions?

Accepted Answer

A)  ATP 
B)  carbon dioxide 
C)  water 
D)  lactic acid 
E)  sodium 
A)  ATP 
B)  carbon dioxide 
C)  water 
D)  lactic acid 
E)  sodium

Question 6

An isotonic 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 during contraction. 
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 during contraction. 
D)  a muscle produces increasing tension as it shortens. 
E)  a muscle produces tension, but the length of the muscle is increasing.

Question 7

A myofilament is the

Accepted Answer

A)  cell membrane of a muscle fiber. 
B)  cytoplasm of muscle cells. 
C)  structural and functional unit of the skeletal muscle cell. 
D)  contractile thread that extends the length of the muscle fiber. 
E)  protein strand composed of actin or myosin. 
A)  cell membrane of a muscle fiber. 
B)  cytoplasm of muscle cells. 
C)  structural and functional unit of the skeletal muscle cell. 
D)  contractile thread that extends the length of the muscle fiber. 
E)  protein strand composed of actin or myosin.

Question 8

Synaptic vesicles in the neuromuscular junction contain

Accepted Answer

A)  calcium. 
B)  ATP. 
C)  acetylcholine. 
D)  acetylcholinesterase. 
E)  sodium. 
A)  calcium. 
B)  ATP. 
C)  acetylcholine. 
D)  acetylcholinesterase. 
E)  sodium.

Question 9

What is a cross-bridge?

Accepted Answer

A)  a protein found along the groove of the F-actin double helix 
B)  a T tubule and two adjacent terminal cisternae 
C)  the combination of myosin heads with active sites on actin molecules 
D)  the movement of myosin head while attached to actin myofilament 
E)  after exercise, the oxygen taken in that exceeds the oxygen required for resting metabolism 
A)  a protein found along the groove of the F-actin double helix 
B)  a T tubule and two adjacent terminal cisternae 
C)  the combination of myosin heads with active sites on actin molecules 
D)  the movement of myosin head while attached to actin myofilament 
E)  after exercise, the oxygen taken in that exceeds the oxygen required for resting metabolism

Question 10

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 cell membrane. 
E)  None of these choices is 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 cell membrane. 
E)  None of these choices is correct.

Question 11

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 it's 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 it's 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 12

Myosin is also known as the

Accepted Answer

A)  thick myofilament. 
B)  thin myofilament. 
C)  intermediate myofilament. 
D)  short myofilament. 
E)  sarcomere. 
A)  thick myofilament. 
B)  thin myofilament. 
C)  intermediate myofilament. 
D)  short myofilament. 
E)  sarcomere.

Question 13

Skeletal muscle develops from multinucleated cells called

Accepted Answer

A)  fascicles. 
B)  myoblasts. 
C)  myofibrils. 
D)  myotomes. 
E)  fasciculi. 
A)  fascicles. 
B)  myoblasts. 
C)  myofibrils. 
D)  myotomes. 
E)  fasciculi.

Question 14

Arrange the following list of biochemical events in the correct sequence. (1) An action potential is conducted deep into the muscle fiber by the T tubule.
(2) Calcium ions bind to troponin.
(3) The membranes of the sarcoplasmic reticulum become more permeable to calcium ions.
(4) Calcium ions diffuse into the sarcoplasm around the myofibril.
(5) The troponin-tropomyosin complex moves exposing active sites.

Accepted Answer

A)  1, 5, 2, 3, 4 
B)  1, 3, 4, 2, 5 
C)  1, 2, 3, 4, 5 
D)  1, 3, 2, 5, 4 
E)  1, 4, 3, 2, 5 
A)  1, 5, 2, 3, 4 
B)  1, 3, 4, 2, 5 
C)  1, 2, 3, 4, 5 
D)  1, 3, 2, 5, 4 
E)  1, 4, 3, 2, 5

Question 15

The diffusion of calcium ions into a smooth muscle cell does not depolarize the membrane so no action potential occurs.

Accepted Answer

A) True 
 B)False

Question 16

Heather is watching a movie. What type of chemical pathway do her muscles depend upon at this time?

Accepted Answer

A)  anaerobic respiration 
B)  aerobic respiration 
C)  both anaerobic and aerobic respiration 
A)  anaerobic respiration 
B)  aerobic respiration 
C)  both anaerobic and aerobic respiration

Question 17

Myosin phosphatase

Accepted Answer

A)  activates myosin kinase. 
B)  forms the cross-bridge. 
C)  removes phosphate from myosin. 
D)  binds to calcium-calmodulin complex. 
E)  opens calcium channels. 
A)  activates myosin kinase. 
B)  forms the cross-bridge. 
C)  removes phosphate from myosin. 
D)  binds to calcium-calmodulin complex. 
E)  opens calcium channels.

Question 18

Muscle myofibrils

Accepted Answer

A)  are found in the sarcolemma. 
B)  extend from the sarcolemma to the T-tubule. 
C)  contain myosin and actin myofilaments. 
D)  hold muscle cells together. 
E)  do not appear striated. 
A)  are found in the sarcolemma. 
B)  extend from the sarcolemma to the T-tubule. 
C)  contain myosin and actin myofilaments. 
D)  hold muscle cells together. 
E)  do not appear striated.

Question 19

When an action potential reaches the presynaptic terminal,

Accepted Answer

A)  calcium ions diffuse into the presynaptic terminal through voltage-gated ion channels. 
B)  acetylcholine moves into the presynaptic terminal. 
C)  a local potential is generated in the presynaptic terminal. 
D)  ligand-gated ion channels in the presynaptic terminal are opened. 
E)  nothing else happens. 
A)  calcium ions diffuse into the presynaptic terminal through voltage-gated ion channels. 
B)  acetylcholine moves into the presynaptic terminal. 
C)  a local potential is generated in the presynaptic terminal. 
D)  ligand-gated ion channels in the presynaptic terminal are opened. 
E)  nothing else happens.

Question 20

Which of the following would contribute to muscular fatigue in the muscle fiber?

Accepted Answer

A)  the emotional state of an individual 
B)  depletion of ATP reserves 
C)  inability of the motor neuron to produce sufficient quantities of acetylcholine 
D)  depletion of neurotransmitter 
E)  blocked receptors in the postsynaptic membrane 
A)  the emotional state of an individual 
B)  depletion of ATP reserves 
C)  inability of the motor neuron to produce sufficient quantities of acetylcholine 
D)  depletion of neurotransmitter 
E)  blocked receptors in the postsynaptic membrane

Exam 9: Muscular System: Histology and Physiology

Treppe

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

Which of the following statements concerning types of muscle contractions is false?

Which type of muscle tissue is autorhythmic?

You are hired to work in a laboratory to measure the rate of human muscle contraction. Which of the following might decrease in quantity in muscle cells undergoing contractions?

An isotonic contraction is described as

A myofilament is the

Synaptic vesicles in the neuromuscular junction contain

What is a cross-bridge?

The electrical properties of cells are the result of

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

Myosin is also known as the

Skeletal muscle develops from multinucleated cells called

The diffusion of calcium ions into a smooth muscle cell does not depolarize the membrane so no action potential occurs.

Heather is watching a movie. What type of chemical pathway do her muscles depend upon at this time?

Myosin phosphatase

Muscle myofibrils

When an action potential reaches the presynaptic terminal,

Which of the following would contribute to muscular fatigue in the muscle fiber?

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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