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96 terms

Muscular System

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the tissue surrounding an entire muscle cell is knows as ....
epimysium
the tissue the surround a muscle fiber is known as ...
endomysium
muscle fibers are bundled into groups known as ...
fascicles
bundles of muscle fibers are wrapped by a tissue known as ...
perimysium
a connective tissue on the surface of muscles (that extends onto the tendon and bone) is known as ...
fascia
One of the characteristics of muscle tissue is that is has conductivity. Which of the following best describes this characteristic?
Muscles have local electrical charges that are capable of moving along the muscle fiber.
One of the characteristics of muscle tissue is that is has extensibility. Which of the following best describes this characteristic?
muscles can be stretched when needed
One of the characteristics of muscle tissue is that is has excitability. Which of the following best describes this characteristic?
muscles contract when stimulated
which of the following groups are considered to be parts of the series-elastic components of muscle?
endomysium, perimysium, epimysium, fascia, and tendons
which of the following best describes the function of the series-elastic component of muscle?
these are not excitable or contractile, but are extensible and elastic
what part of a muscle is the muscle fiber?
muscle cell itself
the outer membrane of the muscle fiber is known as the ...
sarcolemma
the sytoplasm within the muscle fiber is known as the ....
sarcoplasm
the sytoplasm within the muscle fiber contains a molecule to distribute oxygen within the cell. this molecule is known as...
myoglobin
the molecule within the cytoplasm of a muscle fiber that supplies quick energy for contradiction is ...
glycogen
THE MYOFILAMENTS WITHIN THE MUSCLE FIBER ARE COMPOSED OF THREE ITNTEGRAL ITEMS. WHICH OF THE FOLLOWING LISTS THE COMPONENTS CORRECTLY?
myosin, actin, and elastic (titin) filament
thick filaments within the myofibril are composed of ...
myosin
thin filaments within the myofibril are composed primarily of ...
actin
the elastic filaments within a myofibril are composed of molecules known as ....
titin
the elastic filaments within a myofibril are attatched to and wound around ...
myosin
in the myofibril, ATP is used for which of the following?
muscle tone, muscle contraction, muscle relaxation
which of the following tissues has the greatest ability to repair itself?
smooth muscle
of the following muscle types, which one has long, cylindrical-shaped cells?
skeletal
of the following muscle types, which one has only one nucleus?
smooth muscle
which one does NOT have striations?
smooth
which one is usually voluntary?
skeletal
objects that move through organs that are surrounded by smooth muscle are often moved by means of ...
peristalsis
which one is found in the middle layer of the aorta?
smooth
the "all-or-none" concept of skeletal muscle contradiction means that ...
muscle fibers contract completely
which of the following best describes the use of the muscle tone in the body?
keeps our backs straight and our heads up
actions potential frequency is best described as ...
the number of action potential produced per unit of time.
triads in skeletal muscle consist of which of the following?
two terminal cisternae and a T-tubule
when acetylcholine is broken down by acyetylcholinesterasne in the synaptic cleft, what happens to choline?
it is reabsorbed at the presynaptic terminal and combines with mer acetic acid to make acetylcholine.
the recovery stroke in a muscle contraction involves which of the following?
return of the myosin head to its original position after the cross bridge releases.
which of the following is one of the primary functions of muscle tissue?
heat production
the ability of a muscle to be stimulated is called ...
excitability
which of the following muscles is involuntary and is the most widely found throughout the body?
smooth
which of the following types of muscles contain intercalated discs and branching fibers?
cardiac
which of the following muscle types contain peripherally located, multiple nuclei in its cells?
skeletal
the striations in striated muscle correspond with actual molecular structures. which of the following is the z line?
an attatchment point for actin molecules
which is the i band?
a band where only actin molecules are found
which is the h zone?
a band where only myosin is found
which is the a band within a myofibril?
myosin myofilaments in a profile
which of the following is the unit in a myofibril from z line to z line?
sarcomere
which of the following best describes a muscle motor unit?
one nerve fiber and all the muscle fibers innervated by that nerve
the change in electrical potential caused by shifts in ions across the membrane is known as ...
action potential
during an action potential, calcium un released into the sarcoplasm. which of the following is the best explanation of what the calcium does?
removes the tropomyosin block
when the myosin head flexes into a bend, pulling the thin filament along with it, this is called the ...
power stroke
when the thick and the thin filaments pull together, which of the following is TRUE?
the sarcomere gets shorter
the tissues of cardiac muscle have unique structures known as ...
intercalated discs
intercalated discs are capable of doing which of the following?
pass electrical stimulation to toher cardiac cells
which of the following is unique about cardiac muscle tissue?
the cells have large mitochondria
which of the following is TRUE of cardiac tissue?
it has abundant glycogen and myoglobin and is aerobic
which of the following proteins attatches z discs to myosin myofilaments?
titin
the functional connection between a nerve fiber and a muscle fiber is called an ...
synapse
when neuron stimulates a muscle fiber, what molecule diffuses across the gap between them?
acetylcholine
which substance is released from the sarcoplasmic reticulum?
calcium
muscle fibers and neurons are called electrically excitable cells because ...
their plasma membranes exhibit voltage changes in response to stimulation
movement of which of the following proteins causes exposure of the active sites on the actin molecule?
tropomyosin
what type of molecule is acetylcholine?
its a neurotransmitter
binding of acetylcholine with its receptor on muscle cells causes ...
opening of ligan-gated sodium channel
what kind of molecule is ACh?
protein
in the muscle fiber, what is the function of acetylcholinesterase?
it deactivates acetylcholine
what is the voltage of the resting potential of the sarcolemma?
-70 mv
which of the following is a molecule that binds to a receptor?
acetylcholine
which of the following assures quick removal of neurotransmitter at the junction between a nerve and a muscle?
acetylcholinesterase
a buildup of acetycholine in the synaptic cleft without breakdown may cause which of the following?
spastic paralysis
in a muscle twitch, which of the following represents the time between application of a stimulus and the beginning of contraction?
lag
which of the following determines the height of the peaks in multiple motor until summation?
the amounf of tension produced by the number of motor units responding
which of the following would represent incomplete tetanus?
multiple contractions with slight relaxation
which of the following explains why treppe takes place in muscle contractions?
increased calcium levels around the myofibrils
which of the following is true of an isometric muscle contraction?
the amount of tensions increases during contraction
eccentric muscle contractions occur when ...
a person slowly lowers a heavy weight
all of the following are TRUE of muscle tone except ...
depends on multiple motor units contracting in phase with each other
smooth body movements result from ...
both incomplete and complete titanic contractions of motor units contracting out of phase with each other.
active tension in a muscle is defined as ...
the tension applied to a load when the muscle contracts
the sum of active and passive tension is called ...
total tension
which of the following types of muscle fatigue represents depletion of ATP?
muscular
which of the following types of fatigue is caused by the release of more acrtylcholine than can be produced to replace it?
synaptic
muscle soreness can be produced by which of the following?
muscular fatigue, enzymes in the extracellular fluid commonly found within muscle, collagen in the extracellular fluid
which of the following represents extreme muscular fatigue when the muscle is incapable of either contracting or relaxing?
physiological contracture
which of the following energy storages source is most commonly used during the first 10 seconds of exercise?
creatine phosphate
during anaerobic respiration, what is the net amount of ATP produced?
2 ATP
which of the following represents the amount of oxygen that is necessary for the body to recover from anaerobic respiration?
oxygen debt
all of the following are characteristics of slow-twitch fibers except ...
large diameter
all of the following are true about fast-twitch fibers except ...
high amount of myoglobin
which of the following is true about distribution of fast and slow twitch fibers in the body?
slow twitch fibers are usually more resistant to fatigue
a person with an arm immobilized in a cast for 6 weeks will ...
develop muscular atrophy
which of the following effects of exercise elevate the body temperature?
elevated metabolism from the oxygen debt, vasodilation of blood vessels in the skin, skeletal muscle contractions
unitary smooth muscle is found in which of the following locations in the body?
digestive tract, reproductive tract, urinary tract
which of the following is true about the smooth muscle?
the resting membrane potential is less negative in skeletal muscle
which of the following are the most common neurotransmitters in smooth muscle?
acetylcholine and norepinephrine
all of the following are properties of cardiac muscle cells except ...
shorter in duration of contraction than skeletal muscle
which of the following is not an effect of aging on skeletal muscle?
increased myoglobin
which of the following exercises slows the loss of muscle fibers in older people?
swimming
which of the following is true about skeletal muscle fibers in aging people?
the numbers of fibers decreases, there is a decreased density of capillaries that supply muscle cells, the number of motor neurons that innervate skeletal muscle decreases.