Exam 1 Flashcards
responds to a stimulus
excitability(irritability)
ability to generate a pull or tension
contractability
ability to lengthen or stretch beyond resting length
extensible
ability to return to its original shape
elasticity
achieved by exiting info from the muscle or limb, and then adjusting the info (signal) entering the muscle
coordination
composed of brain and spinal cord
CNS
all branches of nerves that lie outside the spinal cord
PNS
Sensory nerves
afferent
motor nerves
efferent
functional unit of the nervous system
neuron
bring info from other neurons
dendrites
usually located in the gray matter of CNS
Soma
axons located in cerebral cortex and descend into spinal cord
upper motor neuron
located in ventral horn of spinal cord
innervates muscle fiber
lower motor neuron
largest and fastest nerve fibers (sense preconception, touch)
Type A
Smallest and slowest nerve fibers (Pain and temp)
Type C
muscle belly is surrounded by
epimysium
bundle of muscle fibers
fascicles
fascicles are separated by
perimysium
each muscle fiber is surrounded by
endomysium
each muscle fiber consists of a
myofibril
are composed of proteins organized into sarcomeres
myofibril
functional contractile unit of the myofibril
sarcomere
constitutes the motor unit
neuron and its branches
all or none principle states that
when motor unit is activated, all of the muscle fibers contract within milliseconds
variable between contractions is
how many units are being recruited
motor unit that has slow contraction speed, small neuron size, low force, low fatigability
Slow twitch oxidative (Type 1)
motor unit that has fast contraction speed, large neuron size, high force, high fatigability
Fast-twitch glycolytic (Type IIB)
motor unit with fast contraction speed, large neuron size, high force, medium fatigability
fast-twitch oxidative (Type IIA)
force of a muscle is determined by
number of motor units actively stimulated at the same time
sensory receptors that transform mechanical distortion in the muscle of join into nerve impulses to affect a motor response
proprioceptors
proprioceptor found in muscle belly (gives position of length of muscle)
muscle spindle
proprioceptor that monitors tension in a muscle
golgi tendon organ (GTO)
generates inhibitory potential to “relax” in the muscle
modulates force so you get just enough to overcome load
GTO
warm ups can
enhance neural input by increasing motor unit activity
Polymetrics improve
velocity and power output- rapidly stretching a muscle and immediately following with contraction of muscle
EMG stand for
electromyography
EMG looks at
which muscles are working, when and the magnitude
muscle activitity where muscle stays the same length
isometric
shortening of muscle, muscle activity where muscle wins battle
concentric
abduct arm with weight is
concentric
putting arm down slowly from abducted position is
eccentric
lengthening of muscle
eccentric
principle muscle producing a motion, prime mover
agonist
provides opposite anatomic action of agonist (Usually inactive during activity)
antagonist
muscle contract at same time as agonist (may provide similar action or obstruct an unwanted action)
Synergist
greater ranger of shortening and greater movement velocity
parallel (Fusiform)
slower movements, but more muscle fibers, giving greater cross sectional area
pennation
sum total of all cross sections of fibers in muscle in plane perpendicular to direction of fibers
Physiological cross sectional area (PCSA)
PCSA is ________ proportional to amount of force generated by a muscle
directly
as angle , the _____ of it changes as well
torque (strength)
cord like connective tissue that connects skeletal muscle to bone
tendons
transmit forces of the muscle to the bone to generate movement
tendon
EMG activity is higher during ______ contraction compared to ______ contraction
concentric, eccentric
concentric muscle action is
positive work
eccentric muscle action is
negative work
______ able to generate greatest amount of torque
eccentric
______ least amount of torque
concentric
