Muscle Flashcards
What is the sarcolemma?
Plasma membrane of muscle fiber
What is sacromere?
Smallest functional until of muscle fiber
What is the sarcoplasmic reticulum?
Tubular network around each myofibril
What is sarcoplasm?
Cytoplasm of muscle fiber
i band
Length of the actin filaments
Sarcolemma
Membrane surrounding muscle fibers
H band
Space between the ends of the actin filaments
Aponeuroses
Broad sheets attached to other muscles
Perimysium
Surrounding each muscle fascicle
Endomysium
Covers each muscle fiber
Creatine phosphate
Stores energy; regenerates ATP from ADP-P
Sliding filament theory
A myosin cross bridge attaches to an actin filament, and then the power stroke drags the 2 filaments past one another
Smooth muscle
Muscle in the digestive tract
Fast twitch fibers
High speed or power activities
Cross-bridge
Protruding part of the myosin filament. Includes myosin head which binds to an active site in an actin filament to produce a power stroke
Z line
Middle of the I band
Vesicles
Store neurotransmitters
Muscle tone
Continuous state of sustained contraction of motor units in a muscle
Summation
The summing of all individual changed in a neuron’s membrane potential
Transverse tubules
Allows nutrients to be transported and nerve impulses to be transmitted rapidly to individual myofibrils
Action potential
A rapid and substantial depolarization of the membrane of a neuron of muscle cell that is conducted through the cell
Isometric contraction(static)
Action in which a muscle contracts without moving, generating force while it’s length remains unchanged
Threshold
Minimum level of stimulus to cause a contraction
Tetanus
Highest tension developed by a muscle in response to stimulation of increasing frequency
