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41 terms

ch 10 anatomy

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the dense layer of connective tissue that surrounds an entire skeletal muscle is the
epimysium.
fascicle.
perimysium.
tendon.
endomysium.
epimysium
The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the
superficial fascia.
endomysium.
perimysium.
periosteum.
epimysium
endomysium
An ________ can be described as a broad tendinous sheet
apineurosis
The repeating unit of a skeletal muscle fiber is the
myofibril.
sarcoplasmic reticulum.
myofilament.
sarcolemma.
sarcomere
sarcomere
The plasma membrane of a skeletal muscle fiber is called the
sarcoplasm.
sarcoplasmic reticulum.
sarcosome.
sarcolemma.
sarcomere.
sarcolemma
The region of the sarcomere containing the thick filaments is the
I band.
A band.
M line.
H band.
Z line.
A band
At rest, the tropomyosin molecule is held in place by
myosin molecules.
troponin molecules.
ATP molecules.
actin molecules.
calcium ions.
troponin molecules
The area in the center of the A band that contains no thin filaments is the
I band.
M line.
H band.
zone of overlap.
Z line.
h band
Each thin filament consists of
chains of myosin molecules.
a rod-shaped structure with "heads" projecting from each end.
a double strand of myosin molecules.
two actin protein strands coiled helically around each other.
six molecules coiled into a helical structure
two actin protein strands coiled helically around eachother
At rest, active sites on the actin are blocked by
calcium ions.
ATP molecules.
myosin molecules.
tropomyosin molecules.
troponin molecules.
tropomysosin molecules
The thin filaments of striated muscle are made primarily of which protein(s)?
troponin
tropomyosin
nebulin
actin
All of the answers are correct
all
The protein that regulates muscle contraction by controlling the availability of active sites on actin is called ________.
tropomyosin
The protein that is found in the Z line of a sarcomere is called _
actinin
Thin filaments are mostly made of the protein
actin
thick filaments are mostly made of the protein
myosin
in a neuromusuclar junction, synaptic vesicles in the motor neuron contain which neurotransmitter?
acetylcholine (ACh)
When an action potential arrives at the axon terminal of a motor neuron, which ion channels open?
voltage-gated calcium channels
What means of membrane transport is used to release the neurotransmitter into the synaptic cleft?
exocytosis
The binding of the neurotransmitter to receptors on the motor end plate causes which of the following to occur?
a.Binding causes voltage-gated sodium channels to open in the motor endplate.
b.Binding causes potassium voltage-gated channels to open in the motor endplate.
c.Binding causes chemically gated potassium channels to open in the motor end plate.
d.Binding of the neurotransmitter causes chemically gated sodium channels to open in the motor end plate.
d
How is acetylcholine (ACh) removed from the synaptic cleft?
AChE
The action potential on the muscle cell leads to contraction due to the release of calcium ions. Where are calcium ions stored in the muscle cell?

a.cytosol
b.sarcolemma
c.terminal cisternae of the sarcoplasmic reticulum
d.T tubule
c
Each skeletal muscle fiber is controlled by a motor neuron at a single
neuromuscular junction
Receptors for acetylcholine are located on the
a.sarcomere.
b. synaptic cleft.
c. synaptic knob.
d.transverse tubule.
e.motor end plate.
e
The action potential is conducted into a skeletal muscle fiber by

a.motor end plates.
b.transverse tubules.
c.sarcoplasmic reticulum.
d.triads.
e.neuromuscular junctions.
b
When calcium ion binds to troponin,
ANSWER:
a. active sites on the myosin are exposed.
b.myosin shortens.
c.tropomyosin moves into the groove between the helical actin strands.
d.actin heads will bind to myosin.
e.muscle relaxation occurs.
c
After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as
ANSWER:
a. treppe.
b. tetany.
c. oxygen debt.
d. depolarization.
e. rigor mortis.
e
The cytoplasm of the neuromuscular terminal contains vesicles filled with molecules of the neurotransmitter
ANSWER:
a.antidiuretic hormone.
b.norepinephrine.
c.acetylcholine.
d.epinephrine.
e.adrenaline
c
Which statement about excitation-contraction coupling is incorrect?
ANSWER:
a.Troponin binds calcium ion and signals tropomyosin to move.
b.Calcium ion is released from the sarcoplasmic reticulum.
c.Relaxation requires uptake of calcium ion by the sarcoplasmic reticulum.
d.Calcium ion is released from the transverse tubule.
e.Tropomyosin moves to expose myosin binding sites on actin.
d
A single motor neuron together with all the muscle fibers it innervates is called
ANSWER:
an end foot.
a motor unit.
a myotome.
an end plate.
a dermatome
b
The type of contraction in which the muscle fibers do not shorten is called
ANSWER:
tetany.
isometric.
concentric.
isotonic.
treppe.
isometric
Suppose that you try to pick up an object and discover that it is much heavier than you expected. Which process must occur in the muscle to increase tension so you can pick up the object?
ANSWER:
recruitment
treppe
complete tetanus
isotonic contraction
wave summation
a
A muscle produces its highest tension when in complete ________.
tetanus
A single contraction-relaxation cycle in a muscle fiber produces a ________.
twitch
During the Cori cycle, in the liver
ANSWER:
a. glucose is released from glycogen.
b. lactic acid is shuffled to muscle cells.
c. glucose is produced from lactic acid.
d. lactic acid is produced from glucose.
e. lactic acid is produced from pyruvic acid.

Correct
c
During the recovery period the body's need for oxygen is increased because
ANSWER:
a. the muscles are not producing ATP.
b. the individual is panting.
c. the liver requires more oxygen to produce lactic acid.
d. muscle cells are producing energy anaerobically.
e. additional oxygen is required to restore energy reserves consumed during exercise.
e
A resting muscle generates most of its ATP by
ANSWER:
a. glycogenolysis.
b. anaerobic respiration.
c. the tricarboxylic acid cycle.
d. hydrolysis of creatine phosphate.
e. aerobic metabolism of fatty acids
e
Creatine phosphate
ANSWER:
a. is only formed during strenuous exercise.
b. cannot transfer its phosphate group to ADP.
c. can replace ATP in binding to myosin molecules during contraction.
d. is produced by the process of anaerobic respiration.
e. acts as an energy reserve in muscle tissue
e
During anaerobic glycolysis
ANSWER:
a. oxygen is not consumed.
b. ATP is produced.
c. carbohydrate is metabolized.
d. pyruvic acid is produced.
e. All of the answers are correct.
e
Aerobic metabolism normally provides ________ percent of the ATP demands of a resting muscle cell.
ANSWER:
25
100
95
50
70
95
Which of these would lead to increased oxygen consumption?
ANSWER:
a. increased muscle activity
b. increased heat production
c. increased aerobic respiration by muscle cells
d. increased conversion of lactic acid to glucose
e. All of the answers are correct.
e
During activities requiring aerobic endurance
ANSWER:
a. most of the muscle's energy is produced in mitochondria.
b. fatigue occurs in a few minutes.
c. glycogen and glycolysis are the primary sources of reserve energy.
d. oxygen debts are common.
e. oxygen is not required.
a