SCI 335 Week 5 Quiz 8

SCI 335 Week 5 Quiz 8 | Wilmington University

Week 5: Test: Chapters 8

Question 1

The outermost layer of connective tissue surrounding a skeletal muscle is called the    

·         perimysium.  

·         sarcomysium.  

·         epimysium.  

·         endomysium.

Question 2

The functional connection between the neuron and the skeletal muscle fiber is the    

·         synapse.  

·         dendrite.  

·         tendon.  

·         fascia.

Question 3

Rigor mortis that occurs in skeletal muscles a few hours after death is due to    

·         excessive ATP.  

·         a decrease of ATP and increased permeability to calcium.      

·         excessive ATP and decreased permeability to calcium.

Question 4

__________ is responsible for degrading acetylcholine so that it does not remain in the synapse.    

·         Acetylase  

·         Acetylcholinesterase  

·         Nicotinase  

·         Amylesterase

Question 5

Multiunit smooth muscle   

·         is composed of sheets of muscle cells.  

·         None of these is correct.  

·         occurs in the walls of the stomach and intestines.  

·         tends to display rhythmicity.

Question 6

Put the following steps for contraction in the correct sequence.

(1) The muscle impulse reaches the sarcoplasmic reticulum and calcium is released.

(2) Thin filaments are pulled over the thick filaments.

(3) Calcium floods the sarcoplasm and binds to troponin molecules slipping off the active sites.

(4) The impulse arrives at the synapse and travels through the transverse tubules.

(5) The muscle fiber shortens and contracts.

(6) Tropomyosin molecules bind to the exposed active sites allowing actin and myosin to form linkages.    

·         4, 1, 3, 6, 2, 5  

·         6, 3, 1, 4, 2, 5  

·         2, 5, 3, 1, 4, 6  

·         3, 5, 2, 1, 6, 4

Question 7

In order to stimulate skeletal muscle fibers, motor neurons release the neurotransmitter ______.

Question 8

Compared to skeletal muscle, smooth muscle    

·         contracts more slowly and relaxes more slowly.  

·         contracts more rapidly and relaxes more slowly.  

·         contracts more slowly and relaxes more rapidly.  

·         contracts more rapidly and relaxes more rapidly.

Question 9

A muscle cramp is most likely due to a lack of   

·         actin.  

·         ATP.  

·         myosin.  

·         ADP.

Question 10

The all-or-none response means that    

·         when a muscle fiber contracts, it contracts completely.  

·         all of the muscles in a region contract together.  

·         all of the muscle fibers within a muscle contract together.  

·         when a muscle fiber contracts, all of its ATP is changed to ADP.

Question 11

The pigment responsible for the reddish brown color of skeletal muscle is called ______.

Question 12

At the neuromuscular junction, the muscle fiber membrane is folded to form a    

·         motor neuron.  

·         neurotransmitter.  

·         motor unit.  

·         motor end plate.

Question 13

ADP molecules on the surface of actin serve as active sites for the formation of cross-bridges with molecules of    

·         myosin.  

·         ATP.  

·         troponin.  

·         tropomyosin.

Question 14

Oxygen debt in muscles may develop because of

·         too many mitochondria utilizing oxygen to synthesize ATP when skeletal muscles are contracted for a minute or two.  

·         the inability of respiratory and circulatory systems to supply enough oxygen to skeletal muscles when used strenuously for a minute or two.  

·         too much oxygen used in forming pyruvic acid when skeletal muscles are contracted strenuously for a minute or two.  

·         the inability of myoglobin molecules to store enough oxygen when skeletal muscles are used strenuously for a minute or two.

Question 15

Creatine phosphate serves to    

·         cause the decomposition of ATP.  

·         cause the decomposition of ADP.  

·         supply energy for the synthesis of ATP.  

·         supply energy for the change of ATP to ADP.

Question 16

The combining of a series of twitches to produce a sustained contraction is called ______.

Question 17

ATP is related to creatine phosphate by    

·         both being required to stimulate a muscle to contract.  

·         ATP supplying energy to synthesize creatine phosphate from creatine and phosphate.  

·         both having three phosphate groups.  

·         creatine phosphate supplying energy to regenerate ATP from ADP and phosphate

Question 18

The functional unit of contraction is    

·         the sarcomere.  

·         the myosin cross-bridge.  

·         the muscle fiber.  

·         the muscle.

Question 19

Which of the following major events in muscle contraction are stated properly?    

·         Tropomyosin molecules move and expose specific sites on myosin filaments.  

·         All of these are correct.  

·         Cross-bridges form between actin and sarcolemma filaments.  

·         Actin filaments slide inward along myosin filaments.

Question 20

The role of ATP in muscle contraction is to supply energy for    

·         myofilament movement.  

·         glycogen synthesis.  

·         creatine phosphate synthesis.  

·         cellular respiration.

Question 21

The rhythmic, wavelike motion produced by smooth muscles in tubular visceral organs is called _______.

Question 22

The ______ ______ at the ends of cardiac muscle cells help to hold adjacent cells together.

Question 23

Myofibrils are composed primarily of    

·         troponin.  

·         tropomyosin.  

·         actin and myosin.  

·         ATP and ADP.

Question 24

A neuromuscular junction can be described as    

·         a site where neurotransmitters are released into the synaptic cleft from the motor neuron.  

·         being composed of a junction between a motor neuron and a muscle fiber.  

·         All of these are correct.  

·         a site where there is actually a gap, or cleft, between the neuron and muscle.

Question 25

A broad, fibrous sheet of connective tissue that attaches the coverings of adjacent muscles is called a(n) ______.

Question 26

During anaerobic respiration, glucose molecules are converted into molecules of ______ ______.

Question 27

Short muscle cells with centrally located nuclei are    

Question 28

A forceful, sustained muscle contraction is called a ______ ______.

Question 29

The amount of oxygen needed to support the conversion of lactic acid to glycogen is called the    

·         refractory quantity.  

·         oxygen debt.  

·         aerobic conversion.  

·         anaerobic concentration.

Question 30

The first event in muscle fiber contraction is that    

·         the muscle fiber membrane is stimulated and a muscle impulse travels deep into the fiber through transverse tubules.  

·         calcium ions diffuse from sarcoplasmic reticulum into the sarcoplasm and bind to troponin molecules.

·         stimulation occurs when acetylcholine is released from the end of the motor neuron.  

·         acetylcholine diffuses across a gap at a neuromuscular junction.