Learn: Chapters 10-11 Vocab Quiz #2

Acetylcholine

Primary neurotransmitter transmitting signals from nerve cells to muscles, glands, and other cells.

Actin filament

Thin filaments found in a sarcomere.

Action potential

Special type of electrical signal that travels along a cell membrane as a wave.

Depolarization

Process where internal membrane potential of excitable cells becomes more positive.

Excitation-contraction coupling

Process linking a nervous system action potential to mechanical contraction.

Motor end plate

Location of ACh-receptors in the muscle fiber sarcolemma.

Muscle tension

Mechanical force generated by muscle fiber contraction or stretching of elastic structures.

Myasthenia gravis

Chronic autoimmune disorder causing fluctuating weakness and rapid fatigue in skeletal muscles.

Myosin filament

Thick filaments found in a sarcomere.

Neuromuscular junction

Specialized chemical synapse between a motor neuron and a skeletal muscle fiber.

Neurotransmitter

Chemical messengers allowing neurons to communicate with each other or muscles.

Refractory period

Brief interval immediately following an action potential where an excitable cell recovers.

Repolarization

Plasma membrane of a muscle fiber returns to its negative resting state after depolarization.

Sarcoplasmic Reticulum

Specialized form of smooth endoplasmic reticulum found in striated muscle cells.

Sliding Filament theory

Scientific explanation for how muscle fibers contract to generate force.

Synaptic cleft

Microscopic physical space or gap between a presynaptic and postsynaptic neuron.

Synaptic vesicles

Small, spherical, membrane-bound organelles inside presynaptic nerve terminals.

Terminal cisternae

Enlarged, sac-like regions of the sarcoplasmic reticulum that store and release calcium ions.

Triads

Three-part structure that plays a vital role in triggering muscle contraction.

T-tubule

Deep, branching inward folds of the sarcolemma in striated muscle cells.