Final answer:
Low-threshold mechanosensitive (LTM) receptors are mechanoreceptors that respond to mechanical disturbances by opening ion channels within the plasma membrane, contributing to the sense of touch and proprioception. Examples include Meissner's corpuscles in the skin and stereocilia in the ear, which are activated by light touch and sound, respectively.
Step-by-step explanation:
Low-threshold mechanosensitive (LTM) receptors are a type of mechanoreceptor, which are sensory receptors specialized for responding to mechanical disturbance such as bending, touch, pressure, motion, and sound. These receptors play a critical role in our sense of touch and proprioception, which is the perception of body position and movement. Mechanosensitive ion channels found within these receptors open in response to mechanical deformation of the cell's plasma membrane, caused by external forces.
One example is the mechanically gated channels in the skin, like Meissner's corpuscles, which are rapidly adapting and respond to light touch. Similarly, the stereocilia in the human ear are mechanosensitive structures connected to ion channels that transduce sound into electrical signals for the brain. These receptors ensure that when ions such as sodium or potassium are low inside the cell, they have a driving force to enter when the channel opens, a process influenced by membrane potential changes due to mechanical stimuli.