Pain is caused by the stimulation of free nerve endings.

Thermoreceptors are free nerve endings sensitive to heat and cold.

They have free nerve endings in the skin.

Tactile pads are characterized by high concentrations of free nerve endings.

Free nerve endings are the pain receptors for protection of the temporomandibular joint itself.

Thus, different free nerve endings work as thermoreceptors, cutaneous mechanoreceptors and nociceptors.

Also, Meissner's corpuscles do not detect pain; this is signalled exclusively by free nerve endings.

In addition, Eimer distinguished a separate set of nerve fibres with free nerve endings.

Free nerve endings can detect temperature, mechanical stimuli (touch, pressure, stretch) or pain (nociception).

Intermediate adapting: Some free nerve endings are intermediate adapting.

Afferent nerve endings without mechanoreceptor cells are called free nerve endings.

They project peripheral processes to the tissues in the form of free nerve endings which are sensitive to molecules indicative of cell damage.

A proposed explanation for the reduced sensitivity is the induced quiescence of free nerve endings following long term corneal exposure to contact lenses.

Polymodality, multiple stimulus modalities (e.g. free nerve endings)

Free nerve endings are unencapsulated and have no complex sensory structures, unlike those found in Meissner's or Pacinian corpuscles.

Lasers can emit a radiant-heat pulse stimulus to selectively activate A-delta and C free nerve endings.

The electroreceptors of monotremes consist of free nerve endings unlike the specialised receptor cells of fish and amphibians.

The dolphin's sense of touch is also well-developed, with free nerve endings densely packed in the skin, especially around the snout, pectoral fins and genital area.

They are all innervated by Aβ fibers, except the mechanorecepting free nerve endings, which are innervated by Aδ fibers.

Slowly adapting: Slowly adapting mechanoreceptors include Merkel and Ruffini corpuscle end-organs, and some free nerve endings.

During the 1890s, Frey proposed that pain is an independent tactile quality, alongside touch, heat and cold, and that it is associated with stimulation of high threshold free nerve endings.

The SI joint is a pain-sensitive structure richly innervated by a combination of unmyelinated free nerve endings and the posterior primary rami of spinal segments L2-S3.

Polymodality is the feature of a single receptor of responding to multiple modalities, such as free nerve endings which can respond to temperature, mechanical stimuli (touch, pressure, stretch) or pain (nociception).

Free nerve endings characterize the nociceptors and thermoreceptors and are called thus because the terminal branches of the neuron are unmyelinated and spread throughout the dermis and epidermis.

Physical exercise may cause pain both as an immediate pain effect that may result from stimulation of free nerve endings by low pH, as well as a delayed onset muscle soreness.