Read here about interoception and its relation to issues of scale.


Interoception is "any sense that is normally stimulated from within the body" (Dorland's Medical Dictionary).


Pulmonary stretch receptors are found in the lungs and control the respiratory rate. Stretch receptors in the gastrointestinal tract sense gas distension that may result in colic pain. Stimulation of stretch sensors that sense dilation of various blood vessels may result in pain, for example headache caused by vasodilation of brain arteries.

Cutaneous vasodilation receptor

Cutaneous receptors in the skin not only respond to touch, pressure, and temperature, but also respond to vasodilation in the skin such as blushing.

Digestive Tract

Stimulation of sensory receptors in the esophagus result in sensations felt in the throat when swallowing, vomiting, or during acid reflux. Sensory receptors in pharynx mucosa, similar to touch receptors in the skin, sense foreign objects such as food that may result in a gag reflex and corresponding gagging sensation. The chemoreceptor trigger zone is an area of the medulla in the brain that receives inputs from blood-borne drugs or hormones, and communicates with the vomiting center. Stimulation of sensory receptors in the urinary bladder and rectum may result in sensations of fullness.