What type of stimuli do free nerve endings respond to?

Free nerve endings are sensory receptors found throughout the body that primarily respond to a variety of stimuli that signal potentially harmful conditions. They are particularly sensitive to extreme mechanical stress, such as intense pressure or stretching, as well as to extreme thermal changes (both hot and cold), and certain chemical stimuli that may indicate tissue damage or inflammation. This capacity allows the nervous system to react quickly to potentially harmful situations.

In contrast, other types of stimuli, such as light touch and pressure, are typically detected by specialized receptors like Merkel cells or Meissner’s corpuscles, which are specifically designed for those functions. Vibrational changes are sensed by pacinian corpuscles, which are adapted to detect rapid changes in pressure and vibration. Joint angles are monitored by proprioceptors such as Golgi tendon organs and muscle spindles, which provide the brain with information about body position and movement.

Thus, the focus of free nerve endings on extreme stimuli helps to explain their role in pain perception and the protective responses of the body to potential threats.