Skeletal Muscle Physiology Flashcards
Contractility
ability of a muscle to shorten. bring bones together, role in movement and posture
Excitability
caapcity of a muscle to respond to a chemical or electrical stimulus
Extensibility
unstimulated muscle passively stretch to and beyond resting length
Elasticity
ability of muscle to recoil to orginal resting length
Series Elastic components
tendons become taut during contraction of muscle
Parallel elastic components
cell membranes
Skeletal
attached to bones. multiple nuclei per cell, located on outer edges. Striated under voluntary and involuntary reflex control
cardiac
heart. single nucleus at the center.Striated, involuntary and intercalated disks
Smooth
walls of hollow organs, blood vessels, eyes, glands, skin. single nucleus located at center. Not striated, involuntary, gap junstions
Tendons
fibrous connective tissue muscle and bone. Elastic anchors
Muscle head
Muscles end attached to more stationary of two bones
Muscle insertion
muscle end attached to bone with greatest movement
Muscle Belly
largest portion of muscle between head and insertion
Synergist
seperate muscles that work together to cause movements
Agonist
muscle causing action when its contracted
antagonist
opposite of agonist. relaxes during agonist contraction
Parallel fiber architecture
parallel to the longitudinal axis of the muscle
Pennate
fibers are at an angle to longitudinal axis. generate greater for per mass but have shorter range
Multinucleated syncytium
developmental origin as fusion of mononucleated cells. Elongated nuclei, cylinderical with tapered ends
Myoblasts
lack of myofibrils. fused together to become myotubes
Myotubes
develop myofibrils and specialized organelles for contraction
Sarcomere
fundamental contractile unit muscle fibers. Contains family of proteins that is anchoring framework and contractile apparatus. causes sarcomere length to shorted. The distance between striations
Sarcolemma
outer membrane that envelops skeletal muscles