[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Physiology](https://durgical.com/en/physiology/) › Nerve and muscle # Nerve and muscle The action potential, the neuromuscular junction and contraction of skeletal, cardiac and smooth muscle. 16 pages ## Exam priority: high - [**Impulse conduction and myelin** Mechanism · Myelin wraps the axon like insulation so the signal jumps from gap to gap; that makes it many…](https://durgical.com/en/physiology/impulse-conduction-and-myelin/) - [**Skeletal muscle excitation–contraction coupling** Mechanism · The electrical signal dives into the muscle fiber through tiny tubes and makes an internal store…](https://durgical.com/en/physiology/skeletal-muscle-excitation-contraction-coupling/) - [**Sliding filaments and the cross-bridge cycle** Mechanism · Muscle shortens because tiny myosin heads grab actin, pull, let go and grab again, burning one…](https://durgical.com/en/physiology/sliding-filaments-and-the-cross-bridge-cycle/) - [**The nerve action potential** Mechanism · A nerve signal is a brief, all-or-none flip of the voltage across the cell membrane, driven by…](https://durgical.com/en/physiology/the-nerve-action-potential/) - [**The neuromuscular junction** Mechanism · Where a motor nerve meets a muscle fiber, it releases acetylcholine; each nerve impulse reliably…](https://durgical.com/en/physiology/the-neuromuscular-junction/) ## Exam priority: medium - [**Fast and slow fibers, energy and fatigue** Concept · Slow red fibers run on oxygen and last for hours; fast white fibers are powerful but tire…](https://durgical.com/en/physiology/fast-and-slow-fibers-energy-and-fatigue/) - [**Length–tension and force–velocity relationships** Concept · A muscle is strongest at a middle length and when it moves slowly; stretched too much, squeezed…](https://durgical.com/en/physiology/length-tension-and-force-velocity-relationships/) - [**Motor units, recruitment and summation** Concept · A muscle grades its force by switching on more nerve–fiber groups and by firing them faster…](https://durgical.com/en/physiology/motor-units-recruitment-and-summation/) - [**Recording membrane potentials, local potentials and repetitive firing** Mechanism · Small stimuli make small local voltage changes that fade with distance; only when they reach…](https://durgical.com/en/physiology/recording-membrane-potentials-local-potentials-and-repetitive-firing/) - [**Refractory periods and excitability** Concept · Right after firing, a nerve cannot fire again for a moment](https://durgical.com/en/physiology/refractory-periods-and-excitability/) - [**Skeletal, cardiac and smooth muscle compared** Table to know · The body has three muscle types: skeletal for movement, cardiac for the heartbeat and smooth for…](https://durgical.com/en/physiology/skeletal-cardiac-and-smooth-muscle-compared/) - [**Smooth muscle contraction** Mechanism · Smooth muscle in vessels, airways and gut squeezes slowly and can hold tone for hours using very…](https://durgical.com/en/physiology/smooth-muscle-contraction/) - [**Smooth muscle innervation and electrical activity** Mechanism · Smooth muscle is switched on by nerves that release transmitter from beads along the axon, by…](https://durgical.com/en/physiology/smooth-muscle-innervation-and-electrical-activity/) - [**Types of nerve fibers** Table to know · Nerves carry fibers of different thickness: thick fast ones for movement and touch, thin slow…](https://durgical.com/en/physiology/types-of-nerve-fibers/) ## For completeness - [**Muscle hypertrophy, atrophy and remodeling** Concept · Muscle grows with load and shrinks with disuse, illness or age, because it constantly builds and…](https://durgical.com/en/physiology/muscle-hypertrophy-atrophy-and-remodeling/) - [**Muscle mechanics: contraction types, work, efficiency and levers** Concept · Muscles turn ATP into force and movement, wasting most of it as heat, and act on bones as levers…](https://durgical.com/en/physiology/muscle-mechanics-contraction-types-work-efficiency-and-levers/) ## A to Z - [A](https://durgical.com/en/physiology/a-z/a/) - [B](https://durgical.com/en/physiology/a-z/b/) - [C](https://durgical.com/en/physiology/a-z/c/) - [D](https://durgical.com/en/physiology/a-z/d/) - [E](https://durgical.com/en/physiology/a-z/e/) - [F](https://durgical.com/en/physiology/a-z/f/) - [G](https://durgical.com/en/physiology/a-z/g/) - [H](https://durgical.com/en/physiology/a-z/h/) - [I](https://durgical.com/en/physiology/a-z/i/) - [L](https://durgical.com/en/physiology/a-z/l/) - [M](https://durgical.com/en/physiology/a-z/m/) - [N](https://durgical.com/en/physiology/a-z/n/) - [O](https://durgical.com/en/physiology/a-z/o/) - [P](https://durgical.com/en/physiology/a-z/p/) - [R](https://durgical.com/en/physiology/a-z/r/) - [S](https://durgical.com/en/physiology/a-z/s/) - [T](https://durgical.com/en/physiology/a-z/t/) - [U](https://durgical.com/en/physiology/a-z/u/) - [V](https://durgical.com/en/physiology/a-z/v/) - [W](https://durgical.com/en/physiology/a-z/w/) [← Physiology](https://durgical.com/en/physiology/) Educational physiology content; not a diagnostic or treatment guide and no substitute for a health professional's advice. Values are approximate references. No doses are given. Representative model, for educational purposes only. --- Source: https://durgical.com/en/physiology/areas/nerve-muscle/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/physiology/areas/nerve-muscle/