The neuromuscular junction (NMJ) is an important synapse in the limbic system of the brain. The neuromuscular junction is the link between a muscle and the internal reproductive organs such as the kidneys.
The neuromuscular junction (NMJ) is an important synapse in the limbic system of the brain. The neuromuscular junction is the link between a muscle and the internal reproductive organs such as the kidneys, spleen, liver, and pancreas. It's the site for the rapid transmission of an action potential across a motor neuron. It's also a site of action for numerous drugs and several diseases.
Myasthenia is an auto-immune disorder of the musculoskeletal system, affecting any one of the following:
- The muscles, bones, or ligaments
- The joints
- The organs such as the heart, lungs, kidneys, and intestines
Besides, it affects the skin and the genitalia. Common symptoms are myasthenic syndrome, referred pain, generalized weakness, decreased muscle strength, impaired walking, and erectile dysfunction. Nerve impulses to the muscles, bones, and joint(s) are slowed or disabled by myasthenia which may be due to a combination of intrinsic and extrinsic causes.
There are two types of synapses: intrinsic and extrinsic. Intrinsic is formed when a current of potassium and calcium passes through a permeable membrane to reach a receiving nerve; this is called a conductive synapse. Extrinsic is where an external force, such as a stretch, pull, or tear of the surrounding tissue close to the nerve or muscle fiber, thereby opening the channel.
Neuromuscular junctions are organized differently in different parts of the body. There is a zone of muscle tension between the nerve trunk and the visceral organs in the abdominal region. There is a zone of constriction between the cervical spine and the upper neck muscles; this is called a tensor fasciae late. The location and formation of these muscle cells are critical to proper nerve function.
Neuromuscular junctions are also organized differently in the brain. In the cerebrum, there is a layer of myelin that is glomuscular in nature. Neuromuscular connections occur in the spinal cord and then throughout the nervous system. The substantia nigra appears to form the central nervous system's bulk, while the other motor nerves exit the spinal cord and travel to various destinations. Besides, the superior cervical ganglion forms a matrix that surrounds the spinal nerve. In contrast, the superior cervical spine provides a framework for the spinosynovium, which provides the muscle fiber with mechanical control.
Neuromuscular junctions form maximal strength areas, where opposing muscle fibers bind and form a circle around a dissipating point. As the muscles contract, the nerve's tension is tuned to provide the requisite torque for movement. Neuromuscular connections are formed by myeloid cells in the brain to form a protective cover for the myelin sheath, which protects the nerve from outside forces. When a muscle fiber is damaged or a scar forms across the myeloid cell, it can restrict the nerve fibers' travel and create local or accumulative damage to the nerve.
Neuromuscular junctions are activated by the release of chemical messengers called chemical inhibitors (Ibuprofen or Neurontin). These inhibitors bind to interfering proteins, called exogenous receptors, that disrupt the synthesis of neurotransmitters. The inhibition of exogenous receptors allows the muscles to resume their function. Still, the chemical inhibitors do not allow the receptors to form a structure called an endplate potential, which allows the nerve to assume its normal permeability.
Neuromuscular junctions are inhibited when a substance called L-Glutamine, a chemical that creates a chemical binding with the GABA(A) receptor and other neurotransmitter inhibitory proteins, becomes reduced. The reduced Glutamine inhibits the formation of new muscle fibers and prevents the growth of existing muscles. Excess amounts of L-Glutamine have been found in people who have Parkinson's' disease and muscular dystrophy. Neuromuscular junction injuries have been seen in patients with Parkinson's disease and alcoholism. In conclusion, the neuromuscular junction represents a dynamic interface between the nervous system and muscle tissue.