Interoceptors

Interoceptors or interoreceptors are a class of receptors . They provide sensory information about the status of the internal body environment via the peripheral nervous system .

Classification

For the classification of receptors, depending on the question, several schemes are used in parallel to one another. So they are z. B. often divided according to the stimulus class , in mechanoreceptors, chemoreceptors, thermoreceptors, etc. However, some of the same receptors are found inside the body as on the surface. Another and independent system, which Charles Scott Sherrington first set up in 1906, divides them according to the source of stimulus. According to this system there are three classes of receptors

Exteroceptors. They provide information about the outside world and are therefore mostly located in the periphery. Examples would be visual receptors (light receptors) as part of the visual system in the eye, chemical receptors in the taste buds as part of the sense of taste, or mechanoreceptors in the fingertips as part of the sense of touch . ( Exception )

Proprioceptors . These provide information about muscle tone and the position and movement ( kinesthesia ) of extremities. ( Proprioception )

Interoceptors. They provide information about the status and milieu of the internal organs ( visceroception )

While the proprioceptors are part of the somatic nervous system , the interoceptors belong to the ( afferent ) vegetative nervous system .

Examples

Some types of interoceptors are:

Baroreceptors (or pressoceptors) in blood vessel walls that measure blood pressure
pH receptors, oxygen receptors and carbon dioxide receptors in the vessel walls to determine the condition of the blood.
Osmoreceptors to regulate fluid requirements
Metaboreceptors of the muscles to determine the metabolism (especially the pH value) of the skeletal muscles
Glucose receptors in the pancreas that regulate insulin levels

properties

Since interoceptors are structured extremely differently according to structure or stimulus class (stimulus), it is hardly possible to specify common properties for them. As with all receptors examined so far, their reaction decreases with unchanged stimulus intensity, often down to zero (adaptation to stimuli). This also applies to receptors that detect slowly changing, almost static stimuli, e.g. B. Blood pressure receptors. The reaction rate of interoceptors is often slow , and they are often innervated by bare (non- mylinized ) nerve fibers.

swell

John T. Cacioppo, Louis G. Tassinary, Gary Berntson: Handbook of Psychophysiology. Cambridge University Press; 3rd edition, 2007.
Elliott Mancall: Gray's Clinical Neuroanatomy. Saunders, 2008.
Maria Patestas, Leslie P. Gartner: A Textbook of Neuroanatomy. John Wiley & Sons

Individual evidence

^ Hermann Rein , Max Schneider : Human Physiology. 15th edition. Springer, Berlin 1964, pp. 650 and 673.

[1] Hermann Rein , Max Schneider : Human Physiology. 15th edition. Springer, Berlin 1964, pp. 650 and 673.