The energy for cross bridge cycling during muscle contraction is provided by
a. acetylcholine.
b. Ca2+.
c. ATP.
d. myosin.
e. actin.
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Question 2) Proteins are primarily digested to and absorbed as
a. amino acids.
b. cellulose.
c. fatty acids and glycerol.
d. monosaccharides.
e. vitamins.
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Question 3) Cross bridge interaction between actin and myosin in skeletal muscle is directly blocked by
a. acetylcholine.
b. triads.
c. Z lines.
d. calcium.
e. tropomyosin.
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Question 4) Fats are digested to
a. amino acids.
b. cellulose.
c. fatty acids and glycerol.
d. fructose.
e. monosaccharides.
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Question 5) Cross bridges
a. extend between the A and I bands and bend to pull the bands together during muscle contraction.
b. are formed by the globular heads of the myosin molecules.
c. link troponin and tropomyosin to actin to form the thin filament.
d. extend from the thick filaments and bind to actin, then bend to pull the thin filaments in closer together during muscle contraction.
e. two of these answers.
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Question 6) Which of the following statements concerning parasympathetic innervation of the digestive tract is incorrect?
a. in general, parasympathetic stimulation is excitatory to the digestive system.
b. parasympathetic innervation to the digestive tract comes primarily through the vagus nerve.
c. parasympathetic innervation is part of the extrinsic nerve supply to the digestive tract.
d. parasympathetic stimulation of the salivary glands produces a saliva rich in mucus.
e. parasympathetic stimulation increases salivary, gastric, pancreatic, and biliary secretion.
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Question 7) During a cross-bridge cycle in skeletal muscle, the
a. cross bridge is energized as myosin ATPase activity hydrolyzes ATP.
b. myosin cross bridge is able to bind with an actin molecule when Ca2+ pulls the troponin-tropomyosin complex aside.
c. linkage between actin and the myosin cross bridge is broken at the end of the cross-bridge cycle as Mg2+ binds to the cross bridge.
d. both (a) and (b) above.
e. all of these answers.
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Question 8) Which factor is not involved in the regulation of digestive system function?
a. autonomous smooth muscle function
b. frontal lobe processing
c. smooth muscle function
d. extrinsic nerves
e. hormones
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Question 9) Which is characteristic of cross bridges?
a. they are a component of thick filaments.
b. they are comprised of actin
c. they have an troponin binding site.
d. they attach to Z lines
e. they allow shortening of the muscle proteins
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Question 10) Which layer of the digestive wall is connective tissue that provided distensibility and elasticity?
a. mucosa
b. submucosa
c. muscular layer
d. serosa
e. myenteric plexus
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