Origin and development of muscle cramps
Marco Alessandro Minetto1, Aleš Holobar, Alberto Botter
1Division of Endocrinology, Diabetology and Metabolism, Department of Internal Medicine, University of Turin, Turin, Italy. marco.minetto@unito.it
Exercise and Sport Sciences Reviews
|October 6, 2012
Summary
Muscle cramps, sudden painful contractions, may stem from altered motor neuron excitability. Recent findings support a central origin for these involuntary muscle spasms, offering new insights into their cause.
Area of Science:
- Neurology
- Muscle Physiology
Background:
- Muscle cramps are characterized by sudden, involuntary, and painful muscle contractions.
- The underlying pathophysiology of cramps is not well understood.
- Two main hypotheses exist: central origin (motor neuron excitability changes) and peripheral origin (motor nerve discharges).
Purpose of the Study:
- To explore the pathophysiology of muscle cramps.
- To evaluate the central origin hypothesis for cramp formation.
- To discuss the implications of recent findings on motor neuron excitability.
Main Methods:
- Review of recent experimental findings related to motor neuron excitability.
- Discussion of the implications of these findings for cramp pathophysiology.
Main Results:
- Recent experimental evidence supports the central origin hypothesis for muscle cramps.
- Findings suggest that alterations in motor neuron excitability play a role in cramp development.
Conclusions:
- The central origin hypothesis, linked to motor neuron excitability, is a plausible explanation for muscle cramps.
- Further research into central mechanisms can enhance understanding of cramp contractions.
Related Concept Videos
01:15Muscle Contraction
95.7K
95.7K
01:10Muscle Contraction
8.6K
In skeletal muscles, acetylcholine is released by nerve terminals at the motor endplate—the point of synaptic communication between motor neurons and muscle fibers. The binding of acetylcholine to its receptors on the sarcolemma allows entry of sodium ions into the cell and triggers an action potential in the muscle cell. Thus, electrical signals from the brain are transmitted to the muscle. Subsequently, the enzyme acetylcholinesterase breaks down acetylcholine to prevent excessive...
8.6K
01:13Formation of Muscle Fibers from Myoblasts
5.7K
De novo myogenesis, or the formation of muscle fibers, begins during the early embryonic stages. The skeletal muscle is formed from somites– blocks of embryonic cell layers. The somites are further divided into dermatomes, myotomes, sclerotomes, and syndetomes. Among these, the myotomes give rise to muscle fibers.
Muscle progenitor cells (MPCs) are formed from the myotomes. MPCs express genes that encode the transcription factors Pax3 and Pax7. Along with Pax 3/7, other transcription...
Muscle progenitor cells (MPCs) are formed from the myotomes. MPCs express genes that encode the transcription factors Pax3 and Pax7. Along with Pax 3/7, other transcription...
5.7K
01:29Relaxation of Skeletal Muscles
5.4K
The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
5.4K
01:20Motor Unit Stimulation
3.5K
When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
3.5K
01:24Generation of Action Potential in Skeletal Muscles
8.2K
Every cell in the body maintains a membrane potential due to an uneven distribution of positive and negative charges across its plasma membrane. The membrane potential is measured in millivolts and quantifies the difference in charge across the membrane.
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
8.2K