Question 1

Diseases that affect the ability of skeletal muscle to contract are considered life threatening because

Accepted Answer

A)  the movement of blood through the blood vessels of the body depends solely on skeletal muscle contractions. 
B)  respiratory movements depend on skeletal muscle contractions. 
C)  movement of food through the digestive tract depends on skeletal muscle contractions. 
D)  All of the choices are correct. 
A)  the movement of blood through the blood vessels of the body depends solely on skeletal muscle contractions. 
B)  respiratory movements depend on skeletal muscle contractions. 
C)  movement of food through the digestive tract depends on skeletal muscle contractions. 
D)  All of the choices are correct.

Question 2

Smooth muscle

Accepted Answer

A)  responds in an all-or-none fashion. 
B)  depolarizes when both Na+ and Ca2+ diffuse into the cell. 
C)  has fast waves of depolarization. 
D)  has fast waves of repolarization. 
E)  has a resting membrane potential that is more negative than skeletal muscle fibers. 
A)  responds in an all-or-none fashion. 
B)  depolarizes when both Na+ and Ca2+ diffuse into the cell. 
C)  has fast waves of depolarization. 
D)  has fast waves of repolarization. 
E)  has a resting membrane potential that is more negative than skeletal muscle fibers.

Question 3

What are caveolae?

Accepted Answer

A)  Ion channels that allow for rapidly developing action potentials 
B)  Shallow invaginations of plasma membrane 
C)  Structures that allow for relatively constant tension maintained for a period of time 
D)  Parts of the intracellular cytoskeleton 
E)  Enzymes that removes phosphate from myosin 
A)  Ion channels that allow for rapidly developing action potentials 
B)  Shallow invaginations of plasma membrane 
C)  Structures that allow for relatively constant tension maintained for a period of time 
D)  Parts of the intracellular cytoskeleton 
E)  Enzymes that removes phosphate from myosin

Question 4

A by-product of anaerobic respiration in muscle fibers is

Accepted Answer

A)  uric acid. 
B)  hydrochloric acid. 
C)  lactate. 
D)  oxygen. 
E)  pyruvate. 
A)  uric acid. 
B)  hydrochloric acid. 
C)  lactate. 
D)  oxygen. 
E)  pyruvate.

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 fibers undergoing contractions?

Accepted Answer

A)  ATP 
B)  Carbon dioxide 
C)  Water 
D)  Lactate 
E)  Na+ 
A)  ATP 
B)  Carbon dioxide 
C)  Water 
D)  Lactate 
E)  Na+

Question 6

An action potential

Accepted Answer

A)  occurs when the local potential reaches threshold level. 
B)  is not propagated. 
C)  has no repolarization phase. 
D)  is an example of negative feedback. 
E)  can be of varying strengths depending on strength of the stimulus. 
A)  occurs when the local potential reaches threshold level. 
B)  is not propagated. 
C)  has no repolarization phase. 
D)  is an example of negative feedback. 
E)  can be of varying strengths depending on strength of the stimulus.

Question 7

Which of the following events occurs on the postsynaptic membrane?

Accepted Answer

A)  Acetylcholine production 
B)  Rapid degradation of acetylcholine 
C)  Release of neurotransmitter 
D)  Neurotransmitter combines with a receptor molecule 
E)  Release of Ca2+ 
A)  Acetylcholine production 
B)  Rapid degradation of acetylcholine 
C)  Release of neurotransmitter 
D)  Neurotransmitter combines with a receptor molecule 
E)  Release of Ca2+

Question 8

The diffusion of Ca2+ into a smooth muscle cell does not depolarize the membrane so no action potential occurs.

Accepted Answer

A) True 
 B)False

Question 9

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)  Ca2+ are 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)  Ca2+ are pumped back into the sarcoplasmic reticulum. 
E)  All of these events occur in the lag phase.

Question 10

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 O2 taken in that exceeds the O2 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 O2 taken in that exceeds the O2 required for resting metabolism

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 of the following would occur as a result of a single muscle contraction?

Accepted Answer

A)  Tetanus 
B)  Tone 
C)  Treppe 
D)  Twitch 
E)  Paralysis 
A)  Tetanus 
B)  Tone 
C)  Treppe 
D)  Twitch 
E)  Paralysis

Question 13

Which of the following correctly describes myoglobin's special function in muscle tissue?

Accepted Answer

A)  Breaks down glycogen 
B)  Synthesizes ATP 
C)  Acts as a reservoir for O2 
D)  Produces action potentials 
E)  Stores glucose 
A)  Breaks down glycogen 
B)  Synthesizes ATP 
C)  Acts as a reservoir for O2 
D)  Produces action potentials 
E)  Stores glucose

Question 14

During resting conditions, ________ is synthesized to store energy.

Accepted Answer

A)  Ca2+ 
B)  creatine phosphate 
C)  creatinine 
D)  lactate 
E)  pyruvate 
A)  Ca2+ 
B)  creatine phosphate 
C)  creatinine 
D)  lactate 
E)  pyruvate

Question 15

Which of the following is NOT a known effect of illegal use of anabolic steroids in large dosages?

Accepted Answer

A)  Increased muscle size 
B)  Kidney damage 
C)  Diminished testosterone secretion 
D)  Increased cardiovascular fitness 
E)  Sterility 
A)  Increased muscle size 
B)  Kidney damage 
C)  Diminished testosterone secretion 
D)  Increased cardiovascular fitness 
E)  Sterility

Question 16

Which of the following statements best distinguishes between tetanus and treppe?

Accepted Answer

A)  Tetanus is due to repeated stimulation of the muscle; treppe is the result of a single long stimulation of the muscle. 
B)  Tetanus occurs when stimulation of muscle occurs frequently with little to no relaxation between stimuli; treppe occurs when stimulation of muscle occurs frequently, but complete relaxation occurs between stimuli. 
C)  Tetanus only occurs in laboratory settings, but treppe occurs all the time in normal muscle activity. 
D)  Tetanus involves increasing the number of motor units stimulated simultaneously; whereas, treppe involves the repeated stimulation of a single muscle fiber. 
A)  Tetanus is due to repeated stimulation of the muscle; treppe is the result of a single long stimulation of the muscle. 
B)  Tetanus occurs when stimulation of muscle occurs frequently with little to no relaxation between stimuli; treppe occurs when stimulation of muscle occurs frequently, but complete relaxation occurs between stimuli. 
C)  Tetanus only occurs in laboratory settings, but treppe occurs all the time in normal muscle activity. 
D)  Tetanus involves increasing the number of motor units stimulated simultaneously; whereas, treppe involves the repeated stimulation of a single muscle fiber.

Question 17

A myofilament is the

Accepted Answer

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

Question 18

Heather is watching a movie. Which type of chemical pathway does her muscles depend on at this time?

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 19

A lack of mitochondria within skeletal muscle fibers would impair which ATP-yielding chemical process?

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 20

The sarcoplasmic reticulum

Accepted Answer

A)  stores Ca2+. 
B)  shortens during muscle contraction. 
C)  transmits nerve impulses to the myofibrils. 
D)  connects adjacent sarcomeres. 
E)  covers the muscle fiber. 
A)  stores Ca2+. 
B)  shortens during muscle contraction. 
C)  transmits nerve impulses to the myofibrils. 
D)  connects adjacent sarcomeres. 
E)  covers the muscle fiber.

Exam 9: Muscular System: Histology and Physiology

Diseases that affect the ability of skeletal muscle to contract are considered life threatening because

Smooth muscle

What are caveolae?

A by-product of anaerobic respiration in muscle fibers is

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 fibers undergoing contractions?

An action potential

Which of the following events occurs on the postsynaptic membrane?

The diffusion of Ca2+ into a smooth muscle cell does not depolarize the membrane so no action potential occurs.

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

What is a cross-bridge?

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

Which of the following would occur as a result of a single muscle contraction?

Which of the following correctly describes myoglobin's special function in muscle tissue?

During resting conditions, ________ is synthesized to store energy.

Which of the following is NOT a known effect of illegal use of anabolic steroids in large dosages?

Which of the following statements best distinguishes between tetanus and treppe?

A myofilament is the

Heather is watching a movie. Which type of chemical pathway does her muscles depend on at this time?

A lack of mitochondria within skeletal muscle fibers would impair which ATP-yielding chemical process?

The sarcoplasmic reticulum

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

Filters

The diffusion of Ca²⁺ into a smooth muscle cell does not depolarize the membrane so no action potential occurs.