Muscle Vocabulary Flashcards
Fascia
Sheet of dense connective tissue that separates individual muscles and helps hold them in position.
Epimysium
Sheath of connective tissue, deep to the fascia, surrounding a skeletal muscle.
Perimysium
Sheath of connective tissue that encloses a bundle of skeletal muscle fibers (encloses a fascicle)
Fascicles
Small bundle of skeletal muscle fibers. A fasciculus pl., fascicles, fasciculi
Aponeurosis
Sheet of connective tissue that attaches muscles to bone, skin, or to the covering of adjacent muscles.
Myofibrils
Contractile fiber in striated muscle cells
Myosin
Protein in a muscle fiber that forms the thick filaments that slide between thin filaments of the protein actin, contracting muscle fibers
Actin
Protein in a muscle fiber that forms the thin filaments that slide between thick filaments of the protein myosin, contracting muscle fibers.
Sarcomere
Structural unit of a myofibril and the functional unit of muscle contraction.
Sarcoplasmic reticulum
Membranous network of channels and tubules within a muscle fiber, corresponding to the endoplasmic reticulum of other cells
Transverse tubules
Any of several membranous channels that extend deep into the cell from a muscle fiber membrane
Cisterna
Enlarged portion of the sarcoplasmic reticulum near the actin and myosin filaments of a striated muscle fiber; pl., cisternae
Synapse
Functional connection between the axon terminal of a neuron and the dendrite or cell body of another neuron or the membrane of another cell type
Neurotransmitters
Chemical than an axon secretes at a synapse that stimulates or inhibits an effector (muscle or gland) or other neuron.
Neuromuscular Junction
Synapse between a motor neuron and skeletal muscle fiber.
Motor end plate
Specialized part of a muscle fiber membrane at a neuromuscular junction.
Synaptic cleft
A narrow extracellular space between two cells at a synapse.
Slidong filament model
The method of muscle contraction in which the actin and myosin filaments slide over each other to shorten the sarcomere.
ATPase
Enzyme that transfers the energy stored in the terminal phosphate bonds of ATP molecules so it can be used by the cell
Acetylcholine
(ACh) Type of neurotransmitter, which is a chemical secreted into the synaptic clefts at the axon ends of neurons.
Acetylcholinesterase
Enzyme that catalyzes breakdown of acetylcholine
Creatine phosphate
Molecule in muscle that store energy
Hemoglobin
Oxygen carrying protein in red blood cells
Myoglobin
Oxygen storing protein in muscle tissue
Lactic acid
Organic compound formed from pyruvic acid in the anaerobic pathway of cellular respiration
Oxygen debt
The amount of oxygen that liver cells require, after aerobic exercise, to convert the accumulated lactate into glucose, plus the amount muscle cells require to restore ATP and creatine phosphate to their original concentrations and to return blood and tissue oxygen levels to normal
Twitch
Single contraction of a muscle fiber followed by relaxation
Latent Period
Time between application of a stimulus and the beginning of a response in a muscle fiber
Summation
Increase force of contraction by a skeletal muscle fiber when a twitch occurs before the previous twitch relaxes
Complete Tetanic Contraction
Continuous, forceful muscular contraction without relaxation.
Motor unit
A motor neuron and the muscle fibers that it controls
Recruitment
Increase in the number of motor units taking part in a muscle contraction
Muscle Tone
Ongoing low-level contraction of some fibers in otherwise resting skeletal muscle.
Peristalsis
Rhythmic waves of muscular contraction in the walls of certain tubular organs
Intercalated Discs
Connection between cardiac muscle cells
Origin
End of a muscle that attaches to a relatively immovable part
Insertion
End of a muscle attached to a movable part
Agonist
A muscle that causes a particular movement
Antagonist
Muscle that opposes a particular movement
Prime Mover
Muscle that provides most of a particular body movement.Also called an agonist.
