MUSCLES Flashcards
A connective tissue partition that separates adjacent fasciculi in a skeletal muscle
Perimysium
A dense layer of collagen fibers that surrounds a skeletal muscle and is continuous with the tendons/aponeuroses of the muscle and with the perimysium.
Epimysium
Bundles of muscle fibers
Fascicle
A delicate network of connective tissue fibers that surrounds individual muscle cells
Endomysium
Embryonic stem cells that function in the repair of damaged muscle tissue
Myosatellite cells
A collagenous band that connects a skeletal muscle to an element of the skeleton
Tendon
A broad tendinous sheet that may serve as the origin or insertion of a skeletal muscle
Aponeurosis
The plasma membrane of a muscle cell
Sarcolemma
The cytoplasm of a muscle cell
Sarcoplasm
The transverse, tubular extensions of the sarcolemma that extend deep into the sarcoplasm, contacting cistern are of the sarcoplasm if reticulum
Transverse T tubules
Organized collections of myofilaments in skeletal and cardiac muscle cells
Myofibrils
The smallest contractile unit of a striated muscle cell
Sarcomeres
Composed primarily of actin
Thin filaments
Composed primarily of myosin
Thick filaments
A myosin head that projects from the surface of a thick filament and that can bind to an active site of a thin filament in the presence of calcium ions.
Cross-bridges
A synapse between a neuron and a muscle cell
Neuromuscular junction
A propagated change in the transmembrane potential of excitable cells, initiated by a change in the membrane permeability to sodium ions.
Action potential
A narrow space, separates the synaptic terminal of the neuron from the opposing sarcolemmal surface
Synaptic cleft
A chemical neurotransmitter in the brain and peripheral nervous system; the dominant neurotransmitter in the peripheral nervous system, released at neuromuscular junctions and synapses of the parasympathetic division
Acetylcholine
A single stimulus-contraction-relaxation cycle in a skeletal muscle
Twitch
If a skeletal muscle is stimulated a second time immediately after the relaxation phase has ended, the resulting contraction will develop a slightly higher maximum tension than did the contraction after the first stimulus
Treppe
When a higher stimulation frequency eliminates the relaxation phase
Complete tetanus
Tension rises and the skeletal muscles length changes
Isotonic contractions
The muscle as a whole does not change length and the tension never exceeds the load
Isometric contractions
A high-energy compound in muscle cells, during muscle activity, the phosphate group is donated to ADP, regenerating ATP.
Creatine phosphate
The complete breakdown of organic substrates into carbon dioxide and water via pyruvic acid; a process that yields large amounts of ATP but requires mitochondria and oxygen
Aerobic metabolism
An anaerobic cytoplasmic breakdown of glucose into lactic acid by way of pyruvic acid, with a net gain of two ATP molecules
Anearobic process/glycolysis
A compound produced from pyruvic under anaerobic conditions
Lactic acid
The conditions in muscle fibers are returned to normal
Recovery period
The amount of oxygen required to restore normal, preexertion conditions
Oxygen debt
Muscle cells found only in the heart
Cardiac muscle cells
Each cardiac muscle cells contacts several others at specialized sites
Intercalated discs
Forms sheets, bundles, or sheaths around other tissues in almost every organ
Smooth muscle tissue
