Anatomy Unit 5: Skeletal Muscles

skeletal muscle functions

movement, temp, entry and exit or mats, support soft tissues

skeletal muscle attachments

tendons, which connect it to skin and bone, eyeballs

skeletal muscle description

cannot make additional smc after young age, under voluntary control, must get stim from neuron

sarcolemma

cell membrane of mc

sarcoplasm

cytoplasm of cm

sarcoplasmic reticulum

smooth er or mc

sarcomere

unit of contraction

excitability

responding to stimuli

conductivity

ability to conduct electric impulses along cm

contractibility

ability to contract and generate force

extensibility

stretchyness and still be able to contract when stretched

elasticity

recoil

epimysium

ct around outside of organ

perimysium

ct that separates fascicles

endomysium

ct inside fascicles, separates muscle fibers

fascicle

bundle of muscle fibers

muscle

contractile organ, attached to bones by tendon, composed of fascicles, supplied w nerves and blood vessels

muscle fiber

single muscle cell, thread like, enclosed in sarcolemma, contains myofibrils

myofibrils

bundle of protein myofilaments, fills most of sarcoplasm, surrounded by sr and mitochondria

sarcomere (muscle)

segment of myofibril, z disc to z disc

myofilaments

fibrous protein strands, thick and thin filaments made of myosin and actin

neuromuscular junction

where neuron contacts smc, has axon term synaptic gap and motor end plate

motor unit

one somatic neuron and all the skeletal muscle cells that it innervates

temporalis

muscle at the temple/ side of head

masseter

chewing muscle, side of cheek

sternocleidomastoid

neck muscle from behind ear to clavicle/sternum

orbicularis oculi

circular muscle around eyes

orbicular oris

circular muscle around mouth

gastrocnemius

calves