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