Final answer:
People with large diameter neuropathy lack feedback support for muscle contractions due to impaired proprioception, impairing balance and coordination. In neuromuscular disorders, the disrupted function of proprioceptive pathways or neuromuscular junctions can result in weak reflexes and paralysis.
Step-by-step explanation:
People with large diameter neuropathy lack feedback support for muscle contractions primarily due to impaired proprioception. Proprioception is the body's ability to sense movement, action, and location, and is essential for coordinating muscle movements and maintaining balance. In neuromuscular disorders, the pathways responsible for conveying proprioceptive signals can be disrupted, leading to impaired control of motor movements. Symptoms can include a decrease in muscle tone, referred to as hypotonia, and functional impairments such as weak reflexes. With the proper functioning of proprioceptive pathways being compromised, the body is unable to accurately monitor and adjust the force and position of muscle contractions, consequently affecting balance and coordination.
In neuromuscular junctions, motor neuron axons release the neurotransmitter acetylcholine which binds to receptors on the muscle fiber sarcolemma, initiating muscle contraction. However, in disorders such as ALS or other systemic neuromuscular disorders, sensory neurons degenerate or synaptic transmission is impaired, preventing normal muscle contraction and leading to symptoms ranging from weakness to paralysis. This disruption in communication can be characterized by a lack of or abnormal synaptic activity, ultimately reducing the effectiveness of muscle control and leading to the symptoms described.