Question 1

Describe the basic sequence of events that occurs as an action potential arrives at the neuromuscular junction and is transmitted to the muscle cell.

Accepted Answer

The action potential triggers the exocyt

Question 2

Which of the following best describes the term sarcomere?

Accepted Answer

A) protein that accounts for elasticity of resting muscle 
B) repeating unit of striated myofibrils 
C) storage site for calcium ions 
D) thin filaments are anchored here 
E) largely made of myosin molecules 
A) protein that accounts for elasticity of resting muscle 
B) repeating unit of striated myofibrils 
C) storage site for calcium ions 
D) thin filaments are anchored here 
E) largely made of myosin molecules

Question 3

Which of the following statements is/are false regarding human muscles?

Accepted Answer

A) Most have both slow and fast fibers. 
B) Slow fibers are abundant in the muscles of the hand. 
C) Eye muscles are composed entirely of fast fibers. 
D) Slow fibers are abundant in the back muscles. 
E) All of the answers are correct; none of them are true regarding human muscles. 
A) Most have both slow and fast fibers. 
B) Slow fibers are abundant in the muscles of the hand. 
C) Eye muscles are composed entirely of fast fibers. 
D) Slow fibers are abundant in the back muscles. 
E) All of the answers are correct; none of them are true regarding human muscles.

Question 4

Identify the incorrect statement about a single motor unit.

Accepted Answer

A) The more neurons involved,the more powerful the contraction. 
B) The smaller the number of muscle fibers,the more precise the movement. 
C) Fine motor skills depend on the development of small motor units. 
D) Some motor units include as many as 2000 muscle fibers. 
E) Muscle fibers of one motor unit intermingle with the fibers of another motor unit. 
A) The more neurons involved,the more powerful the contraction. 
B) The smaller the number of muscle fibers,the more precise the movement. 
C) Fine motor skills depend on the development of small motor units. 
D) Some motor units include as many as 2000 muscle fibers. 
E) Muscle fibers of one motor unit intermingle with the fibers of another motor unit.

Question 5

Each skeletal muscle fiber contains ________ myofibrils.

Accepted Answer

A) 50 to 100 
B) 100 to 150 
C) 150 to 200 
D) 200 to 500 
E) hundreds to thousands 
A) 50 to 100 
B) 100 to 150 
C) 150 to 200 
D) 200 to 500 
E) hundreds to thousands

Question 6

Decreased blood flow to a muscle could result in all of the following except

Accepted Answer

A) muscle fatigue. 
B) an oxygen debt. 
C) an increase in intracellular glycogen. 
D) a shift to anaerobic glycolysis. 
E) an increase in intracellular lactic acid. 
A) muscle fatigue. 
B) an oxygen debt. 
C) an increase in intracellular glycogen. 
D) a shift to anaerobic glycolysis. 
E) an increase in intracellular lactic acid.

Question 7

Figure 10-1 Skeletal Muscle Fiber
Use Figure 10-1 to answer the following questions:
-Which of the following are found in the structure labeled "3"?

Accepted Answer

A) actin 
B) myosin 
C) titin 
D) tropomyosin 
E) All of the answers are correct. 
A) actin 
B) myosin 
C) titin 
D) tropomyosin 
E) All of the answers are correct.

Question 8

Because skeletal muscle contractions demand large quantities of ATP,skeletal muscles have

Accepted Answer

A) a rich nerve supply to ensure a rapid succession of action potentials. 
B) massive creatine phosphate reserves for long periods of sustained contractions. 
C) extra calcium reserves which can serve as fuel molecules during ATP synthesis. 
D) adipose tissue between fibers to supply nutrients for ATP production. 
E) many mitochondria and a rich blood supply. 
A) a rich nerve supply to ensure a rapid succession of action potentials. 
B) massive creatine phosphate reserves for long periods of sustained contractions. 
C) extra calcium reserves which can serve as fuel molecules during ATP synthesis. 
D) adipose tissue between fibers to supply nutrients for ATP production. 
E) many mitochondria and a rich blood supply.

Question 9

A single motor neuron together with all the muscle fibers it innervates is called a(n)

Accepted Answer

A) end foot. 
B) end plate. 
C) motor unit. 
D) dermatome. 
E) myotome. 
A) end foot. 
B) end plate. 
C) motor unit. 
D) dermatome. 
E) myotome.

Question 10

At what point during excitation contraction coupling does exocytosis play a role?

Accepted Answer

A) during calcium ion reuptake into the sarcoplasmic reticulum 
B) when sodium channels open up on the motor end plate 
C) during acetylcholine release from the synaptic terminal 
D) when the action potential surges through the T-tubules 
E) when ATP splits into ADP and P on the free myosin head 
A) during calcium ion reuptake into the sarcoplasmic reticulum 
B) when sodium channels open up on the motor end plate 
C) during acetylcholine release from the synaptic terminal 
D) when the action potential surges through the T-tubules 
E) when ATP splits into ADP and P on the free myosin head

Question 11

At rest,the tropomyosin molecule is held in place by

Accepted Answer

A) actin molecules. 
B) myosin molecules. 
C) troponin molecules. 
D) ATP molecules. 
E) calcium ions. 
A) actin molecules. 
B) myosin molecules. 
C) troponin molecules. 
D) ATP molecules. 
E) calcium ions.

Question 12

The most important factor in decreasing the intracellular concentration of calcium ion after contraction is

Accepted Answer

A) active transport of calcium across the sarcolemma. 
B) active transport of calcium into the sarcoplasmic reticulum. 
C) active transport of calcium into the synaptic cleft. 
D) diffusion of calcium out of the cell. 
E) diffusion of calcium into the sarcoplasmic reticulum. 
A) active transport of calcium across the sarcolemma. 
B) active transport of calcium into the sarcoplasmic reticulum. 
C) active transport of calcium into the synaptic cleft. 
D) diffusion of calcium out of the cell. 
E) diffusion of calcium into the sarcoplasmic reticulum.

Question 13

Thick filaments are made of the protein

Accepted Answer

A) actin. 
B) titin. 
C) myosin. 
D) tropomyosin. 
E) nebulin. 
A) actin. 
B) titin. 
C) myosin. 
D) tropomyosin. 
E) nebulin.

Question 14

The action potential is conducted into a skeletal muscle fiber by

Accepted Answer

A) motor end plates. 
B) neuromuscular junctions. 
C) transverse tubules. 
D) triads. 
E) sarcoplasmic reticulum. 
A) motor end plates. 
B) neuromuscular junctions. 
C) transverse tubules. 
D) triads. 
E) sarcoplasmic reticulum.

Question 15

Describe a motor unit.How many fibers does a motor unit contain?

Accepted Answer

A motor unit consists of all o

Question 16

Creatine phosphate

Accepted Answer

A) is produced by the process of anaerobic respiration. 
B) can replace ATP in binding to myosin molecules during contraction. 
C) acts as an energy reserve in muscle tissue. 
D) is only formed during strenuous exercise. 
E) cannot transfer its phosphate group to ADP. 
A) is produced by the process of anaerobic respiration. 
B) can replace ATP in binding to myosin molecules during contraction. 
C) acts as an energy reserve in muscle tissue. 
D) is only formed during strenuous exercise. 
E) cannot transfer its phosphate group to ADP.

Question 17

A fascicle is a

Accepted Answer

A) group of muscle fibers that are encased in the perimysium. 
B) layer of connective tissue that separates muscle from skin. 
C) group of muscle fibers that are all part of the same motor unit. 
D) group of muscle fibers and motor neurons. 
E) collection of myofibrils in a muscle fiber. 
A) group of muscle fibers that are encased in the perimysium. 
B) layer of connective tissue that separates muscle from skin. 
C) group of muscle fibers that are all part of the same motor unit. 
D) group of muscle fibers and motor neurons. 
E) collection of myofibrils in a muscle fiber.

Question 18

All of the following proteins are part of the thin filaments except

Accepted Answer

A) actin. 
B) tropomyosin. 
C) troponin. 
D) titin. 
E) None of the answers is correct; there are no exceptions. 
A) actin. 
B) tropomyosin. 
C) troponin. 
D) titin. 
E) None of the answers is correct; there are no exceptions.

Question 19

If a second stimulus arrives before the relaxation phase has ended,a second,more powerful contraction occurs.This addition of one twitch to another is called

Accepted Answer

A) incomplete tetanus. 
B) complete tetanus. 
C) treppe. 
D) wave summation. 
E) recruitment. 
A) incomplete tetanus. 
B) complete tetanus. 
C) treppe. 
D) wave summation. 
E) recruitment.

Question 20

Fast fibers

Accepted Answer

A) have low resistance to fatigue. 
B) rely on aerobic metabolism. 
C) have many mitochondria. 
D) have twitches with a very brief contraction phase. 
E) have low resistance to fatigue and quick twitches. 
A) have low resistance to fatigue. 
B) rely on aerobic metabolism. 
C) have many mitochondria. 
D) have twitches with a very brief contraction phase. 
E) have low resistance to fatigue and quick twitches.

Exam 10: Muscle Tissue

Describe the basic sequence of events that occurs as an action potential arrives at the neuromuscular junction and is transmitted to the muscle cell.

Which of the following best describes the term sarcomere?

Which of the following statements is/are false regarding human muscles?

Identify the incorrect statement about a single motor unit.

Each skeletal muscle fiber contains ________ myofibrils.

Decreased blood flow to a muscle could result in all of the following except

Figure 10-1 Skeletal Muscle Fiber Use Figure 10-1 to answer the following questions: -Which of the following are found in the structure labeled "3"?

Because skeletal muscle contractions demand large quantities of ATP,skeletal muscles have

A single motor neuron together with all the muscle fibers it innervates is called a(n)

At what point during excitation contraction coupling does exocytosis play a role?

At rest,the tropomyosin molecule is held in place by

The most important factor in decreasing the intracellular concentration of calcium ion after contraction is

Thick filaments are made of the protein

The action potential is conducted into a skeletal muscle fiber by

Describe a motor unit.How many fibers does a motor unit contain?

Creatine phosphate

A fascicle is a

All of the following proteins are part of the thin filaments except

If a second stimulus arrives before the relaxation phase has ended,a second,more powerful contraction occurs.This addition of one twitch to another is called

Fast fibers

An Introduction to Anatomy and Physiology

The Chemical Level of Organization

The Cellular Level of Organization

The Tissue Level of Organization

The Integumentary System

Osseous Tissue and Bone Structure

The Axial Skeleton

The Appendicular Skeleton

Joints

The Muscular System

Neural Tissue

The Spinal Cord, spinal Nerves, and Spinal Reflexes

The Brain and Cranial Nerves

Sensory Pathways and the Somatic Nervous System

The Autonomic Nervous System and Higher-Order Functions

The Special Senses

The Endocrine System

Blood

The Heart

Blood Vessels and Circulation

The Lymphatic System and Immunity

The Respiratory System

The Digestive System

Metabolism and Energetics

The Urinary System

Fluid, electrolyte, and Acid-Base Balance

The Reproductive System

Development and Inheritance

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