Nerves, Muscles AND Neuromuscular Disorders
Nerve
Nerves are like wiring in our body, made up of fibers called axons covered by myelin. Motor nerves originate from the spinal cord, instructing muscles to move. Sensory nerves transmit information from skin, joints, and organs back to the spinal cord and brain, allowing us to sense touch, vibration, joint movement, and pain. Special senses like vision and hearing have dedicated nerves (optic and cochlear) transmitting information to specific areas in the brain. The vestibular part of a nerve informs the brain about head movements. Diseases affecting nerves are called neuropathies.
Muscles
Muscles are composed of specialized fibers that contract when stimulated by motor neurons, allowing our limbs to move. The heart also has muscle fibers that contract and relax rhythmically to pump blood. Muscle diseases, like muscular dystrophies or myopathies (resulting from factors like statin use, polymyositis, dermatomyositis), can affect the normal functioning of muscles and are sometimes inherited or caused by genetic factors.
The neuromuscular junction is a tiny gap between motor neurons and muscle fibers. In this gap, a chemical called acetylcholine is released by the nerve ending, causing the muscles to contract. Disorders like myasthenia gravis and Lambert-Eaton Myasthenic Syndrome (LEMS) arise when there are issues with this junction, affecting muscle function. These conditions are known as neuromuscular junction disorders.