A&P CH.10: muscle tissue
muscle tissue is responsive for the ________ of materials within and throughout the body
movement
skeletal muscle fibers are -anucleate -multinucleate -binucleate -uninucleate
multinucleate
which are characteristics of glycolytic fibers?
- white -low concentration of myoglobin
which of the following proteins are found within a sarcomere?
-connection -actin
blood vessels dilivernurients and oxygen to the muscle fibers so that they can produce the molecule _____ which is needed for contraction.
ATP
energy to drive the myosin movement in the sliding filament process is provided in the form of _______
ATP
Storage and movement of materials
Voluntary sphincter muscles of the gastrointestinal and urinary tracts can be kept closed or opened
contraction of a muscle fiber requires that the myosin heads in the thick filament bind to active sites on ______ molecule within the thin filaments
actin
each myosin head in a thick filament can bind to what protein in a thin filament?
actin
with endurance training, it is possible;e for fast _____ fibers to take take on characters of fast _____ fibers.
glycolytic, oxidative
in a concentric isotonic contraction, the tension produces is _____ than the resistance .
greater
Slow muscle fibers are about ____ the diameter of fast muscle fibers.
half
types of isotonic contractions
concentric and eccentric
a person tolerance for exercise _____ with age.
decreases
the motor neuron axon travels through the epimysium and perimysium, and enters the ______, where it delivers a nerve impulse to an individual _______.
endomysium, muscle fiber
muscle connective tissue layer
epimysium
order in which ACh diffuses across the synaptic cleft of a NMJ
-ACh binds to receptors on the motor end plate -the resulting action potential moves down the sarcolemma -the action potential moves down the t- tubules -the action potential reaches the terminal cistern of the SR -calcium ions are releases into sarcoplasm
what can cause muscle fatigue?
-Na+ or K + imbalances -insufficient Ca^2+ -build up of intracellular P¡
thin filaments in smooth muscle cells contain which proteins?
-actin -tropomyosin
where is smooth muscle found?
-around blood vessels -in the wall of the small intestines -in the wall of the uterus
multiunit smog muscle is found in where?
-arrector pili muscles in the skin -iris of eye
Events at the Neuromuscular Junction
-arrival of nerve signal at synaptic knob -calcium entry into synaptic knob -exocytosis of ACh into synaptic cleft -binding of ACh to motor end plate
characteristics of oxidative fibers
-high concentration of myoglobin -use aerobic respiration -red -good for endurance
Smooth muscle shows different length-tension relationship than skeletal muscle because...
-it lacks Z discs but has dense bodies -the arrangement of the thick and thin filaments allow for contraction even when stretched
a neuromuscular junction contains an...
-motor end plate -synaptic cleft -synaptic knob
cross bridge cycling
-myosin heads bind to actin -myosin heads pivot towards the M line -ATP releases the myosin heads -ATPase re-cocks the myosin heads
examples of isometric contraction
-sitting up very straight -holding a yoga pose -pushing on a locked door
steps of cross-bridge cycling
1. cross-bridge formation 2. power stroke 3. release of myosin head 4. reset myosin head
hypertrophy results from an increase in the number of _____ in a muscle cell.
myofibrils
the sarcoplasm of a skeletal muscle fiber contains hundreds to thousands of long, cylindrical structures called _______ that extend the length of the cell.
myofibrils
as a result of exercise, each muscle fiber develops more myofibrils, and each myofibril contains a larger number of ________.
myofilaments
muscle cells store oxygen bound to what molecule?
myoglobin
thick myofilaments are composed of bundles of what protein molecule?
myosin
Slow fibers or type 1 fibers are also called ____ fibers because they contain the pigment myoglobin
red
conduction speed of smooth muscle
slow
relaxation period
tension decreases
slow twitch and fast twitch fibers differ primarily in:
their ATPase which splits ATP
the sodium-potassium exchange pumps moves _____ sodium ions out of the cell for every ______ potassium ions it brings in
3;2
the sarcoplasmic reticulum stores ________ ions needed to initiate muscle contraction
Ca
in a thin filament, individual G-actin molecules are strung together to form _______.
F-actin
in a sarcomere, the ____ zone (or band) is the light, central region pf the A band,
H
when viewed under a light microscope, the light bands, called ____ bands, contain only _____ filaments
I, thin
in smooth muscle cells, the sarcoplasmic reticulum is sparse, and the __ tubules are absent
T
______ distribute the muscle impulse throughout the inside of the muscle fiber.
T-tubules
the _____ discs that anchor the sarcomere on either ending skeletal muscle are absent from smooth muscle cells.
Z
elasticity
a contracted muscle cells recoils to its resting length when the applied tensions is removed.
Extensibility
a muscle cell is capable of extending in length in response to the contraction of opposing muscle cells.
To start a muscle contraction, a nerve impulse causes ______ release at a neuromuscular junction.
acetylcholine
What does ACh stand for?
acetylcholine
to stop motor end plate stimulation, usually acetylcholine is quickly broken down and removed from the receptor by _______.
acetylcholinesterase
cardiac muscle cells use _____ respiration almost exclusively.
aerobic
a muscle cell obtains ATP in the short term via what process
anaerobic respiration
the ATP needed to fuel a 100mm sprint would be supplied primarily from.....
anaerobic respiration
the connective tissue layers in muscle provide: protection, distribution sites for blood vessels and nerves, and a means of ______ to the skeleton
attachment
the rate of rhythmic contraction of cardiac muscle is controlled by the ______ nervous system.
autonomic
troponin
bound to tropomyosin; can bind calcium ions
fascicle
bundle of muscle fibers
the cyclic events of "attach, pivot, detach, return" continue as long as ______ ions remain bound to the troponin
calcium
calmodulin
calcium binding protein
during contraction of smooth muscle, ________ binds to calcium and activates myosin light chain kinase
calmodulin
the wall of the heart is composed of _____ muscle
cardiac
a muscle fiber is what level of organization in the body?
cellular
the long tails of the myosin molecules in the thick filaments point toward the _______ of the filaments.
center
the ACh receptors on the motor end plate are ______ ion channels
chemically-gated
the enzyme acetylcholinesterase resides in the synaptic ______.
cleft
As a result of muscle fiber contraction, thick filaments in neighboring sarcomeres move ______.
closer together
in ______ tetany, a muscle cell is stimulated so frequently that it is not allowed to relax at all between stimuli.
complete
a _______ contraction of the arm muscle allows you to lift a book from the table, while a _______ contraction of he arm muscle allows you to lower the book back down to the table.
concentric, eccentric
when smooth muscle is stretched, it responds by...
contracting then relaxing
the skeletal muscles arranged in layers along the walls of the abdominal cavity and the floor of the pelvic cavity perform what function?
contraction support protection
posture
contraction pf a specific skeletal muscles tables joint
the amount of additional oxygen that must be inhaled in order to restore pre-exercise levels is called oxygen ________.
debt
a sheet of dens irregular connective tissue that is external to the epimysium and separates individual muscles is the ________.
deep fascia
Anchoring point between intermediate filaments and the sarcoplasm
dense body
in a muscle, the perimysium is composed of what type of connective tissue?
dense irregular
Anchoring point between intermediate filaments and the sarcolemma
dense plaque
MLCP
dephosphorylates myosin
a sarcomere is defines as the distance from one Z _____ to the next
disc
after a contraction, muscle returns to its original relaxed position due to its natural _______.
elasticity
muscle tissue demonstrates the property of _____ when it is done contracting and returns to its resting length
elasticity
muscle fiber
elongated multinucleate, cylindrical cell
muscle cell conceive tissue layer
endomysium
true or false: after diffusing across the synaptic cleft, ACh binds to receptors on the synaptic knob
false
true or false: in smooth muscle contraction the thick and tin filaments slide past one another causing the Z lines to move closer together.
false: there are no Z lines in smooth muscle cells
in a transverse section pf a muscle, you can see that each skeletal muscle is actually composed of many _____, which are bundles of muscle fibers.
fascicles
conduction speed of skeletal muscle
fast
a piano player uses her hands for bread quick movements. which muscle fiber type would you therefore predict to be predominant in these muscles.
fast glycolytic
which of the three skeletal muscle fiber types has the largest diameter and provides both power and speed?
fast glycolytic
if used repeatedly for endurance events, ______ fibers can develop the appearance and functional capabilities of ______ fibers.
fast/intermediate
intermediate fibers have a high resistance to _______.
fatigue
overall, as aging progresses, muscle strength and endurance are impaired, and the individual has a tendency to _____ quickly.
fatigue
smooth muscle is composed of short cells that have a _____ shape.
fusiform
each myosin strand has a free _____ and an attached tail
head
temperature regulation
heat is produced as a waste product of energy usage
the diameter of a muscle fiber will predict:
how much power it will produce
an increase in muscle fiber number is called______
hyperplasia
what structure anchors adjacent cardiac muscle cells together?
intercalate disc
cardiac muscle cells form Y shaped branches and join to adjacent muscle cells at junctions called ______ discs.
intercalated
an adult is holding a baby is a steady upright position, when he leans the baby down so it is facing the sky, is an example of an _______ contraction
isometric
during an ______ contraction, the length of the ,muscle does not change.
isometric
the ______ mechanism allows Smoot muscle to maintain muscle contraction without the use of additional ATP
latchbridge
in order to predict how much tension a muscle can produce when contracting, it is important to consider the ______ relationship of thick and thin filaments
length-tension
I band
light band containing thin filaments only
H Zone
lighter region in the middle of an A band
Myofibril
long, cylindrical contractile element within muscle cell
Z- disc
made of dark proteins that create a zig zag line
muscle fiber
metabolic activities, contraction
conduction speed of cardiac muscle
moderate
athletes have more defined muscles than non-athletes even while at rest because they have ______ motor units contracting all the time.
more
The neurons that stimulate muscle contraction are called _____ neurons.
motor
although muscle fibers obey the all-or-none principle, the force of muscle contraction can be varied depending on how many ______ units are used
motor
in a motor unit, a single ________ neuron typically controls numerous muscle fibers in a muscle.
motor
upon release from the synaptic knob, acetylcholine attaches to receptors on the _____.
motor end plate
muscle
multiple bundles housing many muscle fibers
body movement
muscle contract and pull on the tendon that attach the muscles to the bone
a skeletal muscle cell is also called a _____ ____.
muscle fiber
Myofibrils are made of ______.
myofilaments
the point where a motor neuron meets a skeletal muscle fiber is called the ______ junction
neuromuscular
where a motor neuron axon terminal and a muscle cell meet is called a _______ junction.
neuromuscular
the motor end plate is a specialized region of the ________.
sarcolemma
the plasma membrane of a skeletal muscle fiber is called the ________.
sarcolemma
within a myofibril, each _____ shortens as the muscle fiber contracts
sarcomere
within a myofibril, each ______ shortens as the muscle fiber contracts.
sarcomere
within a myofibril, z dies separate the functional contractile units known as ______.
sarcomere
in an isotonic contraction, the muscle fibers __________, resulting in the movement.
shorten or lengthen
cardiac muscle cells are _____ and thicker than skeletal muscle cells, and have only ______ nuclei.
shorter, 1-2
sarcoplasm
site of metabolic processes for normal muscle fiber activities
According to the sliding filament theory, when a muscle contracts, thick and thin filaments _____ past each other, and the ______ shortens.
slide, muscle
the _____ filament theory explains how muscle fibers shorten during contraction.
sliding
smooth muscle contraction is ______, resistant to ______, and usually sustained for an extended period of time.
slow, fatigue
the attachment of ACh to the receptor on the motor end plate causes the receptor to open, allowing _____ ions to enter the muscle fiber.
sodium
the sodium-potassium exchange pump maintains a higher concentration of which ion outside the sarcolemma?
sodium
contractibility
stimulation of muscle cells generates tension within cells
sarcoplasmic reticulum
stores calcium ions needed for muscle contraction
the superficial fascia is also known as the _____.
subcutaneous layer
a "step-wise" increase in the force of contraction of a single muscle fiber or single motor unit due to repeated stimulation is called _______.
summation
the narrow space separating the synaptic knob and the motor end plate is called the _______.
synaptic cleft
a nerve impulse travels through an axon to its _____.
synaptic knob
a cord like structure that attaches muscle to bone is a _____
tendon
the force generated when a skeletal muscle is stimulated to contract is muscle ______.
tension
contraction period
tension increases
T-tubules are located adjacent to _______, which are reservoirs storing the calcium ions required for muscle contraction.
terminal cisternae
the epimysium of a muscle surrounds __________.
the entire skeletal muscle
When calcium ion binds to troponin...
the myosin binding sites o action are exposed
latent period
there is no tension
In a sarcomere, the M-line serves as an attachment site for the ______ filaments and keeps them aligned during contraction and relaxation.
thick
in a sarcomere, the M-line serves as n attachment site for _____ filaments and keeps them aligned during contraction and relaxation.
thick
the H band (or H zone) is more lightly shaded because only _____ filaments are present
thick
a cross section of a myofibril through the A band contains which myofilaments?
thick and thin
a cross section of myofibril through the H zone contains which myofilaments?
thick only
the striated appearance in skeletal muscle cells is due to size and density differences between ______ and ______ filaments
thick/thin
single unit muscle cells contract _____.
together
T tubule
transports the action potential from the sarcolemma throughout the entire muscle fiber
in a skeletal muscle cell, two terminal cistern and the centrally places T-tubule from a structure called a _____.
triad
As the troponin molecules change shape, it moves the _____ molecule to which it is attached, thus exposing the active sites on the G-actin molecules
tropomyosin
the two regulatory proteins associated with thin myofilaments are:
tropomyosin and troponin
calcium ions bind to what protein in a thin myofilament?
troponin
true or false: in the absence of calcium, troponin attaches to tropomyosin to hold it in place on the surface of the F actin strand
true
true or false: most molecules contain a combination of all three muscle types, slow oxidative, fast oxidative, and fast glycolytic
true
true or false: playing the piano with your fingers uses very small motor units.
true
true or false: skeletal muscle is usually attached to the skeleton, but it is also found at the openings between the digestive tract and the external environment and the unitary tracts and the opening to the external environment
true
true or false: smooth muscle cells lack transverse tubules.
true
a single contraction and relaxation of a muscle fiber is referred to as a muscle _________.
twitch
tropomyosin
two intertwined strands; cover myosin binding sites
actin
two intertwined strands; each bead has a myosin binding site
thick filaments are about _____ the diameter of thin filaments.
two times
within a synaptic knob, synaptic _______ contain the neurotransmitter ACh
vesicles
have have hooked a frog calf muscle up to a myogram that records muscle tension. you notice that when you stimulate the muscle contract, then allow it to relax, and stimulate it again, that the next time it contracts the amount go tension generated is equal to the two previous waves added together. this phenomenon is called ___________.
wave summation
individual cardiac muscle cells can be stimulated to generate a muscle impulse ______ stimulation.
without nervous
M- line
appears as a dark protein doc in center of H zone
the endomysium is composed what type of connective tissue?
areolar
the superficial fascia, composed of _____ and adipose connective tissue, separates muscle from skin.
areolar
after breaking your arm, you have a cast on it for three months. when the cast is removes, your arm looks much smaller than it did before. what process caused this to happen?
atrophy
cardiac muscle cells are...
autorhythmic
if a skeletal muscle is injured, surrounding _____ cells may be stimulated to differentiate and assist in its repair and regeneration
satellite
Myofilament
short contractile proteins of two types: thick and thin
in a muscle, the perimysium surrounds ______ muscle cells.
fascicles of
cytoskeleton network
intermediate filaments
aerobic respiration requires the presence of what molecule?
oxygen
an extensive network of blood vessels and Nerve fibers extends through both the epimysium and the _____ of a muscle.
perimysium
fascicle connective tissue layer
perimysium
ATP is generated when the enzyme creatine kinase transfer Pi from creatine _______ to ADP
phosphate
MLCK
phosphorylates myosin
As you hold a barbell and begin to flex your arm in a curl, your biceps brachii slowly lifts the weight by using more and more motor units. This phenomenon, which increases the strength of the contraction, is referred to as__________
recruitment
if a skeletal muscle experiences markedly ______ ______, it loses both mass and tone.
reduced stimulation
sarcolemma
regulates entry and exit of materials
Excitability
restiveness to stimuli
an internal membrane complex in skeletal muscle cells that is similar to smooth endoplasmic reticulum of other cells is called the sarcoplasmic ________.
reticulum