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41 terms

Structure of skeletal muscle

Each muscle is an organ, comprised of skeletal muscle tissue, connective tissue, nervous tissue, and blood.
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Fascia
A sheet of fibrous connective tissue that encloses a muscle.
Fascia
This connective tissue extends beyond the ends of the muscle and gives rise to tendons that are fused to the periosteum of bones.
Aponeuroses
Broad sheets of connective tissue that connects muscles. May attach to bone or to the coverings of adjacent muscles.
Epimysium
The layer of connective tissue around each whole muscle.
Perimysium
Connective tissue that surround individual bundles (fascicles) within each muscle.
Endomysium
A connective tissue layer that surrounds individual muscle fibers.
Fascicle
A bundle of muscle fibers.
Muscle fiber
A single, cylindrical muscle cell.
Sarcolemma
Plasma membrane of a muscle fiber.
Sarcoplasm
The cytoplasm of a muscle fiber.
Myofibril
A long, filamentous organelle found within muscle fibers that has a banded appearance. A series of sarcomeres.
Myosin
Thick filaments of myofibrils are made up of this protein.
Actin
Thin filaments of myofibrils are made up of this protein.
Sarcomeres
The organization of the thin and thick filaments produce striations. These striations form a repeating pattern of units along each muscle fiber called?
Sarcomeres
Extend from Z line - Z line.
I bands
Made up of actin filaments that are anchored to Z lines.
I bands
Another name for light bands.
A bands
Made up up overlapping thick and thin filaments.
A bands
Another name for dark bands.
H zone
In the center of A bands consisting of myosin filaments only.
M line
Bisect each H Zone; consists of proteins that help hold the thick filaments in place.
Z line
Dark zigzag line that bisects each light band (I band) and to which the thin filaments are attached.
Sarcoplasmic reticulum
Beneath the sarcolemma of a muscle fiber, membranous network of channels and tubules of a muscle fiber, corresponding to the endoplasmic reticulum of other cells.
Transverse tubules
Membranous channels that extend inward from a muscle fiber membrane.
Neuron
Nerve cell
Motor neuron
A neuron that transmits impulses from the central nervous system to an effector.
Synapse
The functional connection between the axon of a neuron and the dendrite or cell body of another neuron or the membrane of another cell type.
Neurotransmitters
Chemicals that axons secrete on effectors (muscles or glands) or other neurons.
Effectors
Muscles or glands that effect changes in the body.
Neuromuscular junction
Synapse between a motor neuron and a skeletal muscle fiber.
Motor end plate
Specialized part of a muscle fiber membrane at a neuromuscular junction.
Motor unit
A motor neuron and the muscle fibers that it controls constitute a what?
Origin
The attachment of a muscle's tendon to the stationary bone.
Insertion
The attachment of a muscle tendon to a moveable bone.
Belly
The fleshy portion of the muscle between the tendons.
Synergist
Assist the prime mover.
Prime mover
Muscle with the major responsibility for a certain movement. Also known as the agonist.
Antagonist
A muscle that relaxes while another contracts.
Fixator
Prevents a bone from moving so that the prime mover can move another bone.
Fulcrum
The support on or against which a lever rests, or the point about which it turns.
Lever
A rigid bar pivoted about a fulcrum.