Chapter TWO - Neuromuscular Fundamentals Flashcards
Aggregate muscle action
muscles working together in groups rather than independently to achieve given joint motions
Muscles are named based on varying factors…
shape, size, number of divisions, direction of its fibers, location, points of attachment, action, action and shape, action and sizes, shape and location, location and attachment, location and number of divisions
What plays a role in a muscles ability to exert force?
shape and fiber arrangement, cross-section diameter, ability to shorten,
two major types of fiber arrangements?
parallel and pennate
Subdivide parallel fiber arrangements
flat, fusiform, strap muscles, radiate, sphincter
Flat muscles
thin and broad, originating from broad, fibrous, sheetlike aponeuroses that allow them to spread force over a large area
fusiform muscle
spindle-shaped with a central belly that tapers to tendons on each end.
power focused on small bony pts
strap muscles
uniform in diameter with essentially all their fibers arranged in long parallel manner.
power focused on small, bony targets
radiate muscles
triangular, fan shaped, or convergent,
originate on broad surface, converge to a tendon.
sphincter muscles
circular muscles are endless strap muscles that surround openings and function to close them upon contraction
Subdivide pennate muscles
unipennate, bipennate, multipennate
Unipennate
muscle fibers run obliquely from a tendon on one side only
Bipennate
muscle fibers run obliquely from a central tendon on both sides
Multipennate
muscles have several tendons with fibers running diagonally between them
Irritability or excitability
property of muscles
sensitive or responsive to chemical, electrical, or mechanical stimuli
Contractility
to contract and develop tension or internal force against resistance when stimulated
Extensibility
passively stretched beyond its normal resting length
Elasticity
muscle can return to its original resting length following stretching
Intrinsics
muscles within or belonging solely to the body part on which they act
Extrinsics
muscles that arise or originate outside of (proximal to) the body part on which they act.
Action
specific movement of the joint resulting from a concentric contraction of a muscle that crosses the joint
Innervation
occurs in the segment of the nervous system responsible for providing a stimulus to muscle fibers within a specific muscle or portion of a muscle
Amplitude
range of muscle fiber length between maximal and minimal lengthening
Gaster
central, fleshy portion of the muscle
Tendon
tough flexible bands of fibrous CT, cordlike, connect muscle to bones and other structures
transmit force
Aponeurosis
a tendinous expansion of dense fibrous CT, sheet or ribbon.
fascia to bind muscles together or connecting muscle to bone
Fascia
sheet or band of fibrous CT that envelopes, separates, binds together parts of the body such as muscles, organs, and other soft-tissue structures of the body
Retinaculum
fascial tissue that retains tendons close the the body in certain places such as around joints like the wrist and ankle
origin
structural perspective, the proximal attachment of a muscle or the part that attaches closest to the midline or center of the body
Insertion
the distal attachment, farthest from the midline. the movable part
Isometric contractions
one length. length does not change
static in nature - active tension develops to maintain a particular joint angle.
used to stabilize
Isotonic
the muscle developing tension to either cause or control joint movement.
Dynamic contractions
varying degrees of active tension causing joint angle change.
Subdivide isotonic contractions
concentric or eccentric
concentric contractions
causing movement against gravity or resistance
“positive contractions”
used to accelerate the movement of a body segment from low to high speeds
Eccentric contraction
control movement with gravity or resistance and are described as negative contractions.
force developed is less than that of the resistance.
used to decelerate
Movement differentiation
Study table table 2.2 page 43
Isokinetics
type of dynamic exercise usually using concentric or eccentric muscle contractions in which the speed (or velocity) of movement is constant and muscular contraction (usually maximal contraction) occurs throughout the movement
Agonist
when contracting concentrically, cause the joint motion through a specified plane of motion.
primary movers
agonists muscles that contribute to joint motion more than an agonist due size, shape, location etc..
assisters
agonist muscles that contribute significantly less than primary movers
Antagonist
opposite concentric action from agonists.
“contralateral muscles”
“relax and allow movement during agonist contraction”
when antagonist contract concentrically, perform movement in opposite direction of agonist
Stabilizers
surround the joint or body part and contract to fixate or stabilize the area to enable another limb or body segment to exert force and move.
Synergist
assist in the action of an agonist but are not prime movers
Helping synergists
have an action in common but also have action antagonistic to each other
True synergists
contract to prevent an undesired joint action of the agonist and have no direct effect on the agonist action
Neutralizers
counteract or neutralize the action of other muscles to prevent undesirable movements.
Force couples
occur when 2+ forces are pulling in different directions on an object causing the object to rotate about its axis.
determining muscle action
EMG, electrical muscle stimulation, palpation
CNS has five levels of control they are..
cerebral cortex, basal ganglia, cerebelllum, brain stem, spinal cord
cerebral cortex provides
gross muscle action, sensory stimuli interpreted
basal ganglia
posture and equilibrium, learned movements
cerebellum
integrates sensory responses, motion feedback, timing and intensity of muscle activity (refined movements)
Brain stem
integrates all CNS activity through excitation and inhibition of desired neuromuscular actions, maintains wakefulness
spinal cord
pathway between CNS and PNS, specific control, contains rest of nerves, spinal reflexes
review cranial nerves, spinal nerves, numbers, plexuses
ok
kinesthesis
consciousness of body position and movement in space
review GTO and muscle spindle
ok
tetanus
no relaxation between muscle contractoin
treppe
when a rested muscle is stimulated repeatedly with a maximal stimulus at a frequency that allows complete relaxation between stimuli, creates staircase effect until all contractions are equal
length-tension, force-velocity, angle of pull, neuromuscular unit all…
effect development of tension in a muscle
the angle of pull
decreases as a muscles moves further from anatomical position
concurrent
movement patterns that allow the involved biarticular muscles to maintain a relatively consistent length because of the same action (extension) at both its joints
countercurrent
movement patterns that result in substantial shortening of the biarticular muscle
