Muscles Flashcards
Skeletal muscle
mulitnucleate with striations from Z-discs
Cardiac muscle
Single cells that appear striated by desmosomes and gap junctions
Smooth muscle
single cells, non striated
Muscle structure
myofibril, sarcolema, endomysium, muscle fiber, perimysium, skeletal muscle, epimysium
Tendons
connect muscle to bone
can actively stabilize joints
same basic composition as ligaments
epitenon
sheath the covers entire tendon
paratenon
double layers sheath surrounding areolar tissuet
tenosynovium
epitenon + paratenon
muscle innervation
Via ventral horn alpha motor neurons
Motor unit
alpha motor neuron + all muscle fibres connected to it
parallel muscles
all fibres going along long axis and muscle shortens and bulges when contracted
convergent muscles
Fan shaped, as fibres originate over wide angle but converge to one attachment
not as strong and vectors of force are all over the place
pennate muscles
Like feathers they branch off an internal tendon
can be stronger for less mass
unipennate muscles
muscle on one side of tendon
bipennate muscles
muscle on both sides of tendon
multipennate muscles
tendon branches within muscle
circular muscles
sphincters
axial muscles
position head, vertebrae, rib cage and pelvic floor
appendicular muscles
anything that moves appendicular skeleton
diaphragm
large muscle that when contracted pulls air in
Perineal region
pelvic floor
urogenital triangle (anterior)
anal triangle (posterior)
extrinsic hand muscles
mostly in forearm
intrinsic hand muscles
found in the palm or dorsum
