Chapter 9 Part 10 (multiple choice) Flashcards Preview

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Flashcards in Chapter 9 Part 10 (multiple choice) Deck (27):
1

What is the role of calcium ions in muscle contraction?
A) increase levels of myoglobin
B) bind to regulatory sites on troponin to remove contraction inhibition
C) form hydroxyapatite crystals
D) reestablish glycogen stores

B) bind to regulatory sites on troponin to remove contraction inhibition

2

Which of the following is not a component of the standard treatment for muscle strain?
A) stretching of the muscle
B) ice on the muscle
C) elevation of the limb
D) rest of the muscle

A) stretching of the muscle

3

Which of the following is not a connective tissue sheath that wraps individual muscle fibers?
A) epimysium
B) perimysium
C) aponeurosis
D) endomysium

C) aponeurosis

4

During vigorous exercise, there may be insufficient oxygen available to completely break down pyruvic acid for energy. As a result, the pyruvic acid is converted to ________.
A) hydrochloric acid
B) a strong base
C) stearic acid
D) lactic acid

D) lactic acid

5

When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods?
A) latent period
B) fatigue period
C) relaxation period
D) refractory period

D) refractory period

6

In an isotonic contraction, the muscle ________.
A) changes in length and moves the "load"
B) never converts pyruvate to lactate
C) rapidly resynthesizes creatine phosphate and ATP
D) does not change in length but increases tension

A) changes in length and moves the "load"

7

The muscle cell membrane is called the ________.
A) epimysium
B) perimysium
C) sarcolemma
D) endomysium

C) sarcolemma

8

Which of the following is the correct sequence of events for muscle contractions?
A) neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke
B) motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments
C) neurotransmitter release, muscle cell action potential, motor neuron action potential, release of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke
D) muscle cell action potential, neurotransmitter release, ATP-driven power stroke, calcium ion release from SR, sliding of myofilaments

Which of the following is the correct sequence of events for muscle contractions?

B) motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments

9

The mechanism of contraction in smooth muscle is different from skeletal muscle in that ________.
A) the trigger for contraction is a rise in intracellular calcium
B) the site of calcium regulation differs
C) actin and myosin interact by the sliding filament mechanism
D) ATP energizes the sliding process

B) the site of calcium regulation differs

10

Which of the following describes the cells of unitary smooth muscle?
A) They exhibit spontaneous action potentials.
B) They consist of muscle fibers that are structurally independent of each other.
C) They are used for vision and hair raising.
D) They depend upon recruitment using the autonomic nervous system.

A) They exhibit spontaneous action potentials.

11

Which of the following is not a role of ionic calcium in muscle contraction?
A) removes contraction inhibitor
B) binds with troponin
C) activates epinephrine released from adrenal gland
D) triggers neurotransmitter secretion

C) activates epinephrine released from adrenal gland

12

Which of the following is true about smooth muscle?
A) Smooth muscle, in contrast to skeletal muscle, cannot synthesize or secrete any connective tissue elements.
B) Smooth muscle has well-developed T tubules at the site of invagination.
C) Certain smooth muscle cells can actually divide to increase their numbers.
D) Smooth muscle cannot stretch as much as skeletal muscle.

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

13

Smooth muscle is characterized by all of the following except ________.
A) there are more thick filaments than thin filaments
B) there are no sarcomeres
C) there are noncontractile intermediate filaments that attach to dense bodies within the cell
D) it appears to lack troponin

A) there are more thick filaments than thin filaments

14

Muscle tissue has all of the following properties except ________.
A) contractility
B) excitability
C) extensibility
D) secretion

D) secretion

15

The giant protein titin maintains the organization of the ________ assisting in muscle stretching.
A) A band
B) Z disc
C) M line
D) I band

A) A band

16

Which of the following statements is true?
A) Smooth muscle cells have T tubules.
B) Striated muscle cells are long and cylindrical with many nuclei.
C) Cardiac muscle cells are found in the heart and large blood vessels.
D) Cardiac muscle cells have many nuclei.

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

17

An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is ________.
A) the electron transport chain
B) glycolysis
C) the citric acid cycle
D) hydrolysis

B) glycolysis

18

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

19

The sliding filament model of contraction involves ________.
A) actin and myosin sliding past each other and partially overlapping
B) the shortening of thick filaments so that thin filaments slide past
C) the Z discs sliding over the myofilaments
D) actin and myosin lengthening in order to slide past each other

A) actin and myosin sliding past each other and partially overlapping

20

After nervous stimulation stops, what prevents ACh in the synaptic cleft from continuing to stimulate contraction?
A) the tropomyosin blocking the myosin once full contraction is achieved
B) the action potential stops going down the overloaded T tubules
C) calcium ions returning to the terminal cisternae
D) acetylcholinesterase destroying the ACh

D) acetylcholinesterase destroying the ACh

21

Which of the following statements is most accurate?
A) Myofilaments slide during isometric contractions.
B) Muscle tension remains relatively constant during isotonic contraction.
C) T tubules may be sliding during isotonic contraction.
D) The I band lengthens during isotonic contraction.

B) Muscle tension remains relatively constant during isotonic contraction.

22

What is the most distinguishing characteristic of muscle tissue?
A) the ability to respond to nervous stimulation
B) the diversity of activity of muscle tissue
C) the design of the fibers
D) the ability to transform chemical energy into mechanical energy

D) the ability to transform chemical energy into mechanical energy

23

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) gym climbing
B) playing baseball or basketball
C) a long, relaxing swim
D) a sprint by an Olympic runner

C) a long, relaxing swim

24

Of the following muscle types, which has only one nucleus, no sarcomeres, and rare gap junctions?
A) multiunit smooth muscle
B) cardiac muscle
C) skeletal muscle
D) visceral smooth muscle

A) multiunit smooth muscle

25

Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped, ________.
A) maximum force production would result because the muscle has a maximum range of travel
B) cross bridge attachment would be optimum because of all the free binding sites on actin
C) no muscle tension could be generated
D) ATP consumption would increase because the sarcomere is "trying" to contract

C) no muscle tension could be generated

26

What part of the sarcolemma contains acetylcholine receptors?
A) motor end plate
B) part adjacent to another muscle cell
C) end of the muscle fiber
D) any part of the sarcolemma

A) motor end plate

27

Which of the following statements is false or incorrect?
A) Under normal resting conditions, cardiac muscle tissue contracts and relaxes about 75 times per minute.
B) Cardiac muscle fibers can use lactic acid to make ATP.
C) Cardiac muscle fibers depend mostly on anaerobic cellular respiration to generate ATP.
D) Cardiac muscle contracts when stimulated by its own
autorhythmic muscle cells.

C) Cardiac muscle fibers depend mostly on anaerobic cellular respiration to generate ATP.