Muscle Flashcards
function
generation of force
- movement
- structural support
- glands
- physio
tissue metabolism
contraction is ATP-dependent
highly metabolic –> lots of mitochondria
nutrient supply via blood vessels
tissue types
striated (skeletal/cardiac)
smooth
myoepithelial
glands
myofibroblast
scar tissue
pericytes
blood vessels
skeletal muscle
voluntary, moves skeleton and organs
organization of skeletal muscle
muscle –> surrounded by epimysium
fascicles –> surrounded by perimysium
multinucleate cell = fiber –> surrounded by endomysium
surrounded by fascicles is sarcolemma
sarcoplasm surrounds the area between myofibrils
each muscle fiber divided into bundles of myofibrils and filaments
cross section of skeletal muscle
polygonal
speckled
bundles (fascicles)
peripheral neurons
longitudinal section of skeletal
long
stritated
peripheral nuclei
unbranched
what causes striations in muscle fibers
sarcomeres Z line = junction (middle of I) M line = middle (middle of A, H) A band = actin + myosin (dark band) H band = myosin (lighter area in middle of A, surrounding M line) I band = actin (light band)
what is the myofibril contractile unit
sarcomere
what is a sarcomere made of
myosin + actin
how is skeletal muscle contraction regulated?
fiber twitch rate determined by nerve output (each type has own neural output)
“convergence” - one nerve, many muscle fibers
motor end plate = modified synapse
cardiac muscle structure
striated branched 1-2 nuclei/cell highly vascularized intercalated disks many mitochondria