kin of muscular system Flashcards
is the body a simple machine?
no
muscles
force
bone
lever
joints
axes
normal resting length
when muscle is not short or lengthened
irritability
ability to respond to stimulus resulting in contraction
contractibility
ability to generate force following stimulus
extensibility
ability to stretch with force
elasticity
muscle returns to normal resting length when force is removed
z-lines
separate sarcomeres
actin
pulls sarcomere making is shorter resulting in a contraction
myosin
bind to actin
mm fibers
individual muscle fibers of a small bundle
fascicles
bundle of muscle fibers
muscle anatomy small to big x 5
sarcomere
myofibrils
mm fibrils
fascicles
muscle
Sliding filament theory
myosin head binds to actin
myosin head exert force & pull actin closer for a contract
this repeats
type I muscle fiber
slow twitch
small in diameter
for endurance
response to neural stimulation is slow
type II muscle fibers
fast twitch
large in diameter
for quick short bursts of activity
response to neural stimulation is fast
motor units
a group of muscle fibers innervated by the same motor neuron
T/F: not all motor units are activated during muscle contraction
true!
- high force = some motor units
- low force = few motor units
tendon
muscle to bone
ligament
bone to bone
musculotendinous joint
muscle to tendon
tenoperiosteal joint
tendon to bone
origin
proximal mm attachment
insertion
distal mm attachment
concentric contraction in open chain
insertion moves to the origin
- lifting glass to mouth
concentric contraction in closed chain
origin moves to insertion
- pull-ups
parallel muscle fiber
longer & larger ROM potential
oblique muscle fiber
shorter & greater strength potential d/t numerous fibers
parallel muscle fibers x4
strap
fusiform
rhomboidal
triangular
strap
long thin fibers running entire length of mm
- SCM, sartorius, & rectus abdominis
fusiform
spindle-like fibers that mostly run length of the muscle
- biceps, triceps
rhomboidal
4-sided mm, flat w/ broad attachment @ edge
- rhomboids, pronator quadratus
triangular
flat with fan/triangular appearance
- pec major
oblique muscle fibers x3
unipennate
bipennate
multipennate
unipennate
one side of a feather
- tibialis posterior, semimembranosus
bipennate
feather-like shape
- rectus femoris, interossei of hands
multipennate
3+ branches of oblique fibers separated by tendon
- deltoids, subscapularis
muscles are named after … x7
location
shape
# of heads
size of mm
action
attachment
direction of fibers
agonist
prime mover causes the motion
antagonist
mm that does the opposite motion of the agonist
- prevents joint movement -> STABILITY
- common when learning a new task
stabilizer
mm that supports agonist to work more efficiently
- core mm
- associated with joint
neutralizer
prevents unwanted motion if mm can produce 2+ more actions
- associated with muscles
synergist
muscles work in conjunction w/ another mm enhancing movement
- flexor carpi ulnaris + extensor carpi ulnaris = ular deviation!!!!
active insufficiency
muscle is too short to contract effectively
passive insufficiency
muscle too long to stretch
the distance that a muscle is capable of shortening after it has been elongated to its maximum
functional excursion
hypotonia
reduced muscle tone, floppiness & deceased strength
hypertonia
increased muscle tone
stiffness & reduced movement (spastic or rigid)
