Ch.9-Practice

Depends on oxygen delivery and aerobic mechanisms.

A) Slow (oxidative), fatigue-resistant fibers

B) Fast (oxidative or glycolytic), fatigable fibers

A) Slow (oxidative), fatigue-resistant fibers

Have very fast-acting myosin ATPases and depend upon anaerobic metabolism during contraction.

A) Slow (oxidative), fatigue-resistant fibers

B) Fast (oxidative or glycolytic), fatigable fibers

B) Fast (oxidative or glycolytic), fatigable fibers

Red fibers, the smallest of the fiber types.

A) Slow (oxidative), fatigue-resistant fibers

B) Fast (oxidative or glycolytic), fatigable fibers

A) Slow (oxidative), fatigue-resistant fibers

Contain abundant amounts of glycogen.

A) Slow (oxidative), fatigue-resistant fibers

B) Fast (oxidative or glycolytic), fatigable fibers

B) Fast (oxidative or glycolytic), fatigable fibers

Abundant in muscles used to maintain posture.

A) Slow (oxidative), fatigue-resistant fibers

B) Fast (oxidative or glycolytic), fatigable fibers

A) Slow (oxidative), fatigue-resistant fibers

A relatively high percentage are found in successful marathon runners.

A) Slow (oxidative), fatigue-resistant fibers

B) Fast (oxidative or glycolytic), fatigable fibers

A) Slow (oxidative), fatigue-resistant fibers

The stimulus above which no stronger contraction can

be elicited, because all motor units are firing in the muscle.

A) Treppe

B) Multiple motor unit summation

C) Wave summation

D) Tetanus

E) Maximal stimulus

E) Maximal stimulus

The phenomenon in which the contraction strength of a muscle increases, due to increased Ca2+ availability and enzyme efficiency during the warm-up.

A) Treppe

B) Multiple motor unit summation

C) Wave summation

D) Tetanus

E) Maximal stimulus

A) Treppe

Continued sustained smooth contraction due to rapid stimulation.

A) Treppe

B) Multiple motor unit summation

C) Wave summation

D) Tetanus

E) Maximal stimulus

D) Tetanus

The situation in which contractions become stronger due to stimulation before complete relaxation occurs.

A) Treppe

B) Multiple motor unit summation

C) Wave summation

D) Tetanus

E) Maximal stimulus

C) Wave summation

How a smooth increase in muscle force is produced.

A) Treppe

B) Multiple motor unit summation

C) Wave summation

D) Tetanus

E) Maximal stimulus

B) Multiple motor unit summation

A sarcomere is the distance between two ________.

A) I band

B) A band

C) Myosin

D) Z discs

D) Z discs

The ________ contains only the actin filaments.

A) I band

B) A band

C) Myosin

D) Z discs

A) I band

The thicker filaments are the ________ filaments.

A) I band

B) A band

C) Myosin

D) Z discs

C) Myosin

Both actin and myosin are found in the ________.

A) I band

B) A band

C) Myosin

D) Z discs

B) A band

The myosin filaments are located in the ________.

A) I band

B) A band

C) Myosin

D) Z discs

B) A band

Serves as the actual "trigger" for muscle contraction by removing the inhibition of the troponin molecules.

A) Acetylcholine

B) Acetylcholinesterase

C) Calcium ions

D) Creatine phosphate

E) Aerobic respiration

C) Calcium ions

A neurotransmitter released at motor end plates by the axon terminals.

A) Acetylcholine

B) Acetylcholinesterase

C) Calcium ions

D) Creatine phosphate

E) Aerobic respiration

A) Acetylcholine

A metabolic pathway that provides for a large amount of ATP per glucose because oxygen is used. Products are water and carbon dioxide and ATP.

A) Acetylcholine

B) Acetylcholinesterase

C) Calcium ions

D) Creatine phosphate

E) Aerobic respiration

E) Aerobic respiration

Normally stored in the terminal cisternae of the sarcoplasmic reticulum.

A) Acetylcholine

B) Acetylcholinesterase

C) Calcium ions

D) Creatine phosphate

E) Aerobic respiration

C) Calcium ions

Used to convert ADP to ATP by transfer of a high-energy phosphate group.

A reserve high-energy compound.

A) Acetylcholine

B) Acetylcholinesterase

C) Calcium ions

D) Creatine phosphate

E) Aerobic respiration

D) Creatine phosphate

Destroys ACh.

A) Acetylcholine

B) Acetylcholinesterase

C) Calcium ions

D) Creatine phosphate

E) Aerobic respiration

B) Acetylcholinesterase

The major function of the sarcoplasmic reticulum in muscle contraction is to ________.

A) make and store phosphocreatine

B) provide a source of myosin for the contraction process

C) synthesize actin and myosin myofilaments

D) regulate intracellular calcium concentration

D) regulate intracellular calcium concentration

With muscular dystrophy ________.

A) most cases appear in young females

B) muscle fibers degenerate and atrophy

C) most forms do not appear to be inherited

D) muscles decrease in size due to loss of fat and connective tissue

B) muscle fibers degenerate and atrophy

Which muscle cells have the greatest ability to regenerate?

A) cardiac

B) skeletal

C) no muscle can regenerate

D) smooth

D) smooth

Most muscles contain ________.

A) a predominance of slow oxidative fibers

B) muscle fibers of the same type

C) a mixture of fiber types

D) a predominance of fast oxidative fibers

C) a mixture of fiber types

Fatigued muscle cells that recover rapidly are the products of ________.

A) intense exercise of long duration

B) intense exercise of short duration

C) slow exercise of short duration

D) slow exercise of long duration

B) intense exercise of short duration

The strongest muscle contractions are normally achieved by ________.

A) increasing stimulus above the treppe stimulus

B) increasing stimulus above the threshold

C) recruiting small and medium muscle fibers

D) increasing the stimulation up to the maximal stimulus

D) increasing the stimulation up to the maximal stimulus

Which of the following would be recruited later in muscle stimulation when contractile strength increases?

A) motor units with larger, less excitable neurons

B) large motor units with small, highly excitable neurons

C) many small motor units with the ability to stimulate other motor units

D) motor units with the longest muscle fibers

A) motor units with larger, less excitable neurons

Which of the following is not a usual result of resistance exercise?

A) increase in the number of myofibrils within the muscle cells

B) increase in the efficiency of the respiratory system

C) increase in the number of muscle cells

D) increase in the efficiency of the circulatory system

C) increase in the number of muscle cells

In skeletal muscle contraction, calcium apparently acts to ________.

A) cause ATP to bind to actin

B) increase the action potential transmitted along the sarcolemma

C) release the inhibition on Z discs

D) remove the blocking action of tropomyosin

D) remove the blocking action of tropomyosin

Calcium ions bind to the ________ molecule in skeletal muscle cells.

A) tropomyosin

B) myosin

C) troponin

D) actin

C) troponin

Myoglobin ________.

A) produces the end plate potential

B) is a protein involved in the direct phosphorylation of ADP

C) stores oxygen in muscle cells

D) breaks down glycogen

C) stores oxygen in muscle cells

An elaborate network of membranes in skeletal muscle cells that functions in calcium storage is the ________.

A) myofibrillar network

B) sarcoplasmic reticulum

C) intermediate filament network

D) mitochondria

B) sarcoplasmic reticulum

A sarcomere is ________.

A) the area between two Z discs

B) the wavy lines on the cell seen in the microscope

C) the area between two intercalated discs

D) the nonfunctional unit of skeletal muscle

A) the area between two Z discs

Immediately following the arrival of the stimulus at a skeletal muscle cell there is a short period called the ________ period during which the events of excitation-contraction coupling occur.

A) relaxation

B) latent

C) contraction

D) refractory

B) latent

Creatine phosphate functions in the muscle cell by ________.

A) storing energy that will be transferred to ADP to resynthesize ATP

B) forming a chemical compound with actin

C) inducing a conformational change in the myofilaments

D) forming a temporary chemical compound with myosin

A) storing energy that will be transferred to ADP to resynthesize ATP

After nervous stimulation of the muscle cell has ceased, the calcium ________.

A) is destroyed by cholinesterase

B) level in the cytoplasm drops

C) is actively pumped into the extracellular fluid for storage until the next contraction

D) is chemically bound to the filaments

B) level in the cytoplasm drops

The major function of the sarcoplasmic reticulum in muscle contraction is to ________.

A) regulate intracellular calcium concentration

B) make and store phosphocreatine

C) provide a source of myosin for the contraction process

D) synthesize actin and myosin myofilaments

A) regulate intracellular calcium concentration

The striations of a skeletal muscle cell are produced, for the most part, by ________.

A) a difference in the thickness of the sarcolemma

B) the T tubules

C) the arrangement of myofilaments

D) the sarcoplasmic reticulum

C) the arrangement of myofilaments

Which of the following are composed of myosin?

A) all myofilaments

B) thin filaments

C) Z discs

D) thick filaments

D) thick filaments

During muscle contraction, myosin cross bridges attach to which active sites?

A) Z discs

B) actin filaments

C) myosin filaments

D) thick filaments

B) actin filaments

Which of the following surrounds the individual muscle cell?

A) endomysium

B) perimysium

C) epimysium

D) fascicle

A) endomysium

Smooth muscles that act like skeletal muscles but are controlled by autonomic nerves and hormones are ________.

A) red muscles

B) single-unit muscles

C) white muscles

D) multiunit muscles

D) multiunit muscles

Rigor mortis occurs because ________.

A) sodium ions leak out of the muscle

B) no ATP is available to release attached actin and myosin molecules

C) proteins are beginning to break down, thus preventing a flow of calcium ions

D) the cells are dead

B) no ATP is available to release attached actin and myosin molecules

Which of the following does not act as a stimulus to initiate a muscle contraction?

A) hormonal activity

B) a change in the pH of a muscle

C) a change of temperature

D) neurotransmitters

C) a change of temperature

The term aponeurosis refers to ________.

A) the rough endoplasmic reticulum B) the tropomyosin-troponin complex

C) a sheetlike indirect attachment to a skeletal element

D) the bands of myofibrils

C) a sheetlike indirect attachment to a skeletal element

The oxygen-binding protein found in muscle cells is ________.

A) immunoglobin

B) ATP

C) myoglobin

D) hemoglobin

C) myoglobin

The contractile units of skeletal muscles are ________.

A) T tubules

B) myofibrils

C) microtubules

D) mitochondria

B) myofibrils

The site of calcium regulation in the smooth muscle cell is ________.

A) calmodulin

B) troponin

C) myosin

D) actin

A) calmodulin

One functional unit of a skeletal muscle is ________.

A) a myofibril

B) a myofilament

C) the sarcoplasmic reticulum

D) a sarcomere

D) a sarcomere

The functional role of the T tubules is to ________.

A) hold cross bridges in place in a resting muscle

B) stabilize the G and F actin

C) enhance cellular communication during muscle contraction

D) synthesize ATP to provide energy for muscle contraction

C) enhance cellular communication during muscle contraction

The role of calcium ions in muscle contraction is to ________.

A) act as a third messenger

B) bind to regulatory sites on troponin, changing the configuration

C) reestablish glycogen stores

D) initiate the conversion of carbon dioxide to oxygen for storage

B) bind to regulatory sites on troponin, changing the configuration

The warm-up period required of athletes in order to bring their muscles to peak performance is called ________.

A) wave summation

B) incomplete tetanus

C) treppe

D) twitch

C) treppe

The main effect of the warm-up period of athletes, as the muscle contractions increase in strength, is to ________.

A) increase the myoglobin content

B) convert glycogen to glucose

C) enhance the availability of calcium and the efficiency of enzyme systems

D) tone the muscles and stabilize the joints for the workout

C) enhance the availability of calcium and the efficiency of enzyme systems

During vigorous excercise, there may be insufficient oxygen available to completely break down pyruvic acid for energy. As a result, the pyruvic acid is converted to ________.

A) lactic acid

B) stearic acid

C) hydrochloric acid

D) a strong base

A) lactic acid

When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods?

A) relaxation period

B) latent period

C) refractory period

D) fatigue period

C) refractory period

In an isotonic contraction, the muscle ________.

A) never converts pyruvate to lactate

B) changes in length and moves the "load"

C) rapidly resynthesizes creatine phosphate and ATP

D) does not change in length but increases tension

B) changes in length and moves the "load"

The muscle cell membrane is called the ________.

A) epimysium

B) perimysium

C) sarcolemma

D) endomysium

C) sarcolemma

Smooth muscle is significantly different from striated muscle in several ways. Which of the following is true?

A) Smooth muscle has transverse tubules.

B) The fibers of smooth muscle are arranged quadrangularly.

C) Smooth muscle is larger and more powerful than striated muscle.

D) Smooth muscle contracts in a twisting way.

D) Smooth muscle contracts in a twisting way.

The mechanism of contraction in smooth muscle is different from skeletal muscle in that ________.

A) the site of calcium regulation differs

B) actin and myosin interact by the sliding filament mechanism

C) the trigger for contraction is a rise in intracellular calcium

D) ATP energizes the sliding process

A) the site of calcium regulation differs

The cells of single-unit visceral muscle ________.

A) exhibit spontaneous action potentials

B) are chemically coupled to one another by gap junctions

C) contract all at once

D) consist of muscle fibers that are structurally independent of each other

A) exhibit spontaneous action potentials

Which of the following statements is not true concerning developmental aspects of muscle?

A) Most muscle tissues develop from myoblasts.

B) Skeletal muscle is derived from mesoderm.

C) There is no biological basis for the difference in strength between women and men.

D) Skeletal muscle develops from somites.

C) There is no biological basis for the difference in strength between women and men.

Which of the following is true about smooth muscle contraction?

A) Smooth muscle cannot stretch as much as skeletal muscle.

B) Smooth muscle has well-developed T tubules at the site of invagination.

C) Smooth muscle, in contrast to skeletal muscle, cannot synthesize or secrete any connective tissue elements.

D) Certain smooth muscle cells can actually divide to increase their numbers.

D) Certain smooth muscle cells can actually divide to increase their numbers.

Smooth muscle is characterized by all of the following except ________.

A) it appears to lack troponin

B) there are noncontractile intermediate filaments that attach to dense bodies within the cell

C) there are no sarcomeres

D) there are more thick filaments than thin filaments

D) there are more thick filaments than thin filaments

Muscle tissue has all of the following properties except ________.

A) contractility

B) excitability

C) extensibility

D) secretion

D) secretion

The giant protein titin maintains the organization of the ________ assisting in muscle stretching.

A) M line

B) I band

C) Z disc

D) A band

D) A band

Which of the following statements is true?

A) Striated muscle cells are long and cylindrical with many nuclei.

B) Smooth muscle cells have T tubules.

C) Cardiac muscle cells have many nuclei.

D) Cardiac muscle cells are found in the heart and large blood vessels.

A) Striated muscle cells are long and cylindrical with many nuclei.

An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is ________.

A) the citric acid cycle

B) glycolysis

C) the electron transport chain

D) hydrolysis

B) glycolysis

Muscle tone is ________.

A) a state of sustained partial contraction

B) the feeling of well-being following exercise

C) the ability of a muscle to efficiently cause skeletal movements

D) the condition of athletes after intensive training

A) a state of sustained partial contraction

The sliding filament model of contraction involves ________.

A) the Z discs sliding over the myofilaments

B) actin and myosin shortening but not sliding past each other

C) actin and myosin sliding past each other and partially overlap

D) the shortening of thick filaments so that thin filaments slide past

C) actin and myosin sliding past each other and partially overlap

After nervous stimulation stops, ACh in the synaptic cleft is prevented from continuing stimulation of contraction by ________.

A) the action potential stopped going down the overloaded T tubules

B) the tropomyosin blocking the myosin once full contraction is achieved

C) acetylcholinesterase destroying the ACh

D) calcium ions returning to the terminal cisternae

C) acetylcholinesterase destroying the ACh

Which of the following is most accurate?

A) Muscle tension remains relatively constant during isotonic contraction.

B) The I band lenghtens during isotonic contraction.

C) T-tubles may be sliding during isotonic contraction.

D) Myofilaments slide during isometric contractions.

A) Muscle tension remains relatively constant during isotonic contraction.

The most distinguishing characteristic of muscle tissue is ________.

A) the ability to transform chemical energy into mechanical energy

B) the diversity of activity of muscle tissue

C) the design of the fibers

D) the sarcoplasmic reticulum

A) the ability to transform chemical energy into mechanical energy

Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance. Which of the following athletic endeavors best represents the use of red fibers?

A) playing baseball or basketball

B) mountain climbing

C) a sprint by an Olympic runner

D) a long, relaxing swim

D) a long, relaxing swim

Of the following muscle types, which has only one nucleus, no sarcomeres, and rare gap junctions?

A) cardiac muscle

B) visceral smooth muscle

C) multiunit smooth muscle

D) skeletal muscle

C) multiunit smooth muscle

Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped ________.

A) maximum force production would result since the muscle has a maximum range of travel

B) ATP consumption would increase since the sarcomere is "trying" to contract

C) cross bridge attachment would be optimum because of all the free binding sites on actin

D) no muscle tension could be generated

D) no muscle tension could be generated

An individual has just ingested a chemical that binds irreversibly to the ACh receptors in the sarcolemma. By itself it does not alter membrane potential, yet prevents normal neurotransmitter binding. Ignoring the effects on any other system, the consequence to skeletal muscle would be ________.

A) irreversible contraction as soon as the first nervous stimulation reached the sarcolemma

B) no contraction at all by nervous mechanisms

C) contraction if stimulated by an external electrode

D) no contraction at all by nervous mechanisms, but contraction if stimulated by an external electrode

D) no contraction at all by nervous mechanisms, but contraction if stimulated by an external electrode

What are the similarities between all types of muscle?

A) Skeletal and smooth muscle cells are elongated and are called muscle fibers

B) Muscle terminology is similar: Sarcolemma-muscle plasma membrane

C) Muscle contraction depends on two kinds of myofilaments — actin and myosin

D) Muscle terminology is similar: Sarcoplasm -cytoplasm of a muscle cell

E) All of these are correct!

E) All of these are correct!

What are NOT similarities between all types of muscle?

A) Muscle terminology is similar: Sarcolemma-muscle plasma membrane

B) Skeletal and smooth muscle cells are elongated and are called muscle fibers

C) Muscle contraction depends on two kinds of myofilaments — actin and myosin

D) Muscle terminology is similar: Sarcoplasm -cytoplasm of a muscle cell

E) Muscle terminology is similar: all have chondrocytes in lacunae

E) Muscle terminology is similar: all have chondrocytes in lacunae

Which of the following is incorrect

A) Cardiac muscle is voluntary

B) Smooth muscle is involuntary

C) Skeletal muscle is voluntary

D) Cardiac muscle has striations

E) Skeletal muscle has striations

A) Cardiac muscle is voluntary

Which of the following is incorrect

A) Cardiac muscle has striations

B) Skeletal muscle is voluntary

C) Smooth muscle does peristalsis

D) Skeletal muscle has striations

E) Cardiac muscle is involuntary

C) Smooth muscle does peristalsis

Which below is not a functional characteristic of muscle tissue?

A) Dr. Sweet is the trickster- all of these are correct!

B) Contractility

C) Extensibility

D) Excitability, or irritability

E) Elasticity

A) Dr. Sweet is the trickster- all of these are correct!

Which below is not a functional characteristic of muscle tissue?

A) Enhancibility

B) Elasticity

C) Excitability, or irritability

D) Contractility

E) Extensibility

A) Enhancibility

What is not a general function of muscle tissue?

A) Holding axons to the ligaments

B) Stabilizing joints

C) Producing movement by muscle contraction

D) Maintaining posture

E) Generating heat as they contract

A) Holding axons to the ligaments

What is not a general function of muscle tissue?

A) Dr. Sweet is the trickster: all of these are correct!

B) Producing movement by muscle contraction

C) Generating heat as they contract

D) Maintaining posture

E) Stabilizing joints

A) Dr. Sweet is the trickster: all of these are correct!

Which below is not a tissue sheath associated with skeletal muscle?

A) Epimysium

B) Chondromysium

C) Perimysium

D) Endomysium

B) Chondromysium

Which below is not a tissue sheath associated with skeletal muscle?

A) Endomysium

B) Trick question: all of these are tissue sheaths!

C) Epimysium

D) Perimysium

B) Trick question: all of these are tissue sheaths!

Which below is not a part of a muscle fiber?

A) Glycosomes

B) Myofibrils

C) Aponeurosis

D) Sarcoplasm

E) Myoglobin

C) Aponeurosis

Which below is not a part of a skeletal muscle fiber?

A) Dr. Sweet is the trickster: all of these are correct!

B) Sarcoplasm

C) Glycosomes

D) Myoglobin

E) Many nuclei

A) Dr. Sweet is the trickster: all of these are correct!

Which below is an attachment where the muscle's connective tissue wrapping extend beyond the muscle as a sheetlike structure?

A) direct

B) tendon

C) origin

D) insertion

E) aponeurosis

E) aponeurosis

Which below is an attachment where the muscle's connective tissue wrapping extend beyond the muscle as a ropelike structure?

A) origin

B) insertion

C) aponeurosis

D) tendon

E) direct

D) tendon

Which below is not a part of the myofibril structure?

A) Dark A bands

B) Z disc (or Z line) is a darker area at the midline of the I bands

C) Light I zones

D) M line is a dark line that bisects vertically the H-zone

E) H-zone (zone seen only in relaxed fibers) a lighter stripe in the midsection of each A band

C) Light I zones

Which below is not a part of the myofibril structure?

A) Z disc (or Z line) is a darker area at the midline of the I bands

B) Dark D bands

C) Light I bands

D) M line is a dark line that bisects vertically the H-zone

E) H-zone (zone seen only in relaxed fibers) a lighter stripe in the midsection of each A band

B) Dark D bands

What below is the contractile unit?

A) thin filament

B) t filament

C) B structures

D) not listed

E) actin

D) not listed

What is the contractile unit?

A) Two of these choices

B) actin

C) from Z to Z disk

D) thin filament

E) sarcomere

E) sarcomere

What diffuses in and out of the sarcolemma during a muscle contraction?

A) troponin

B) acetylcholine

C) acetylcholinesterase

D) sodium and potassium

E) tropomysin

D) sodium and potassium

What leads to the release of calcium at the neuromuscular junction?

A) acetylcholine

B) action potential

C) acetylcholinesterase

D) tropomysin

E) troponin

B) action potential

Is the constant, slightly contracted state of all muscles, which does not produce active movement

A) Muscle tone

B) Eccentric contraction

C) Muscle fatigue

D) Oxygen debt

E) Isotonic contraction

A) Muscle tone

Which type of muscle fiber will predominate in a person that runs or swims as fast as possible for 5 minutes, stops, waits a minute, and continues this process 10 times?

A) Fast oxidative fibers

B) Slow oxidative fibers

C) Fast glycolytic fibers

D) Slow glycolytic fibers

A) Fast oxidative fibers