Physio Chapter 12 Part 1 Flashcards
Skeletal muscle attached to bone on each end by _____?
tendons
Prime mover of any skeletal muscle movement is called a what muscle?
Flexors and extensors that act on the same joint to produce opposite actions is called a what muscle?
agonist muscle, antagonist muscle
Tendon connective tissue extends to form fibrous sheath is called a what?
Connective tissue extends into the body of the muscle.
Composed of columns of muscle fibers.
Each of theses are surrounded by perimysium
epimysium, fascicles
When somatic neuron is activated, all the muscle fibers it innervates contract with ____ or _____ contractions
all or none,
Ratio of motor neuron: muscle fibers.
Fine neural control over the strength occurs when many small motor units are involved, this is called the?
Larger and larger motor units are activated to produce greater strength, this is called?
innervation ratio, recruitment
In regards to motor units, each muscle fiber receives a _____ axon terminal from a somatic neuron.
Each axon can have collateral branches to innervate an ______of fibers.
single, equal number
Each myofibril contains ______. There are ____ and _____ filaments
myofilaments, thick and thin
Thick filaments are primarily composed of ______ and thin filaments are primarily composed of _______?
myosin, actin
Sarcomere Z disc to Z disc, in the middle there are ___ lines. These anchor _____ during contraction.
M, mysoin
Elastic protein that runs through the myosin from M line to Z disc.
Contributes to elastic recoil of muscle. This is called what?
Titin
Sliding of filaments is produced by the actions of…
cross bridges
Cross bridges are part of the myosin proteins that extend out toward _____?
Each myosin head contains an ________?
actin, ATP binding site
These bands contain myosin, mover closer and does not shorten during contraction
Distance between A bands of successive sarcomeres.
Decrease in length
Contain only myosin.
Shorten during contraction, are in conjunction with M line
A bands, I Bands, H bands
In muscle contraction myosin binding site splits atp to adp, ADP remain bound to _____ until these heads attach to _____?
mysoin, actin
In muscle contraction, this pulls actin toward the center of the A band.
Power stroke
ADP is released when ____ binds to a fresh ___ at the end of the power stroke.
mysoin, ATP
In muscle contraction, release of ADP upon binding to another ATP, causes the ______ bond to break.
cross bridge
Only 50% of the cross bridges are attached at any given time, this is called the
synchronous action
Regulation of cross bridge attachment to actin due to (2)?
tropomysoin, troponin
In relaxed muscle, _______ blocks binding sites on actin
tropomyosin
When calcium production is blocked what happens to the muscle?
muscle relaxes
In excitation-contraction coupling, ____ diffusion produces end plate potential. + ions are attracted to negative _______. If depolarization is sufficient, threshold occurs, producing an _____.
Na+, plasma membranes, AP
In excitation-contraction coupling, ____ travel down sarcolema and T tubules.
SR terminal cisternae release ____ from chemical channels.
APs, Ca
In excitation-contraction coupling, Ca is also released through a _______ Ca release.
Calcium induced
In excitation-contraction coupling, upon its release Ca attaches to?
Tyropmysoin-troponin complex configuration change occurs, cross bridges attach to _____?
trophonin, actin
In muscle relaxation, ____must cease for the muscle to relax?
These channels have to be closed?
ACh must be degraded? yes or no
APs, Ca, yes
Muscle is stimulated with a single electrical shock (above threshold).
Quickly contracts and then relaxes.
Increasing stimulus increases the strength of the ____ (up to maximum).
twitch
If second electrical shock is administered before complete relaxation of muscle
summation
Stimulator delivers an increasing frequency of electrical shocks.
Relaxation period shortens between twitches.
Strength of contraction increases
incomplete tetanus
Fusion frequency of stimulation.
No visible relaxation between twitches.
Smooth sustained contraction
complete tetanus
Staircase effect.
Electrical shocks are delivered at maximum voltage.
Each shock produces a separate, stronger twitch (up to maximum).
Due to increase in intracellular Ca2+.
Represents “warm-up.”
Treppe
Force of contraction remains constant throughout the shortening process.
Velocity of muscle shortening decreases as load increases
isotonic contraction
Length of muscle fibers remain constant, if the number of muscle fibers activated is too few to shorten the muscle.
Velocity of shortening is 0
isometric contraction
Force exerted on a muscle to stretch, it is greater than the force of muscle contraction.
Muscle will lengthen as it contracts.
eccentric contraction
This is what kind of curve?
Inverse relationship between force opposing muscle contraction and velocity of muscle shortening.
force-velocity curve
in regards to the series-elastic component, non-contractile tendons and connective tissue absorb tension as the _____?
muscle contracts
In regards to the series-elastic component, tnedons first must be pulled tight, before the muscle contraction results in ______?
Tendons have elasticity and display _____.
shortening, recoil (spring back to resting length)
Strength of muscle contraction influenced by:
Frequency of ______.
Thickness of each ______.
Initial ______ of muscle fiber
stimulation, muscle fiber, length
Talking about length-tension relationship,
Length which can generate maximum force is called what?
Few cross bridges can attach is called what?
No cross bridges can attach to actin is called what?
ideal resting length, overlap too small, no overlap
