Ch. 10 Vocab Flashcards
a connective tissue partition that separates adjacent fasciculi in a skeletal muscle
perimysium
a delicate network of connective tissue fibers that surrounds individual muscle cells
endomysium
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 cisternae of the sarcoplasmic reticulum
transverse T tubules
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
the smallest contractile unit of a striated muscle cell
sarcomere
a cytoskeletal filament in a skeletal or cardiac muscle cell; consists of actin, troponin, and tropomyosin
thin filament
a cytoskeletal filament in a skeletal or cardiac muscle cell; composed of myosin, with a core of titin
thick filament
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 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
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
the anaerobic cytoplasmic breakdown of glucose into lactic acid by way of pyruvic acid, with a net gain of two ATP molecules
anaerobic process/glycolysis
a compound produced from pyruvic acid under anaerobic conditions
lactic acid
regions where adjacent cardiocytes interlock and where gap junctions permit electrical coupling between the cells
intercalated discs
muscle tissue in the walls of many visceral organs; characterized as nonstriated, involuntary muscle
smooth muscle tissue
cardiocytes; cells that function in the repair of damaged muscle tissue
cardiac muscle cell
tension rises and the skeletal muscle’s length changes
isotonic contractions
the muscle as a whole doesn’t change length and the tension produced never exceeds the load
isometric contractions
occurs when a higher stimulation frequency eliminates the relaxation phase
complete tetanus
a small bundle; usually refers to a collection of nerve axons or muscle fibers
fascicle
embryonic stem cells that function in the repair of damaged muscle tissue
myosatellite cells
organized collections of myofilaments in skeletal and cardiac muscle cells
myofibrils
a narrow space that separates the synaptic terminal of the neuron from the opposing sarcolemmal surface
synaptic cleft
the staircase phenomenon where a skeletal muscle when stimulated a second time immediately after the relaxation phase has ended, will result in a contraction with a slightly higher maximum tension than did the contraction after the first stimulus
treppe
the time it takes for the conditions in muscle fibers to return to normal, preexertion levels
recovery period
the amount of oxygen required to restore normal, preexertion conditions
oxygen debt
tissue in which cells are short, branched, and striated, usually with a single nucleus; circulates blood and maintains blood pressure; located in the heart
cardiac muscle tissue
