Quick Facts
The skin is predominantly innervated by sensory nerve fibers that detect and respond to physical and chemical stimuli in the environment. Autonomic nerve fibers also innervate structures including the eccrine and apocrine sweat glands, sebaceous glands, arrector pili muscles, and arterioles.
Structure/Morphology
The integumentary system is predominantly innervated by sensory nerve fibers, containing highly specialized sensory receptors that detect and respond to physical and chemical stimuli in the environment. The skin receives many stimuli from the external environment, such as touch, stretch, temperature changes, pain, and pressure. For this reason, it is important that the skin have appropriate sensory receptors responding to these stimuli. This sensory information is relayed to the central nervous system.
Autonomic nerve fibers are also found in the skin. They innervate structures including the eccrine and apocrine sweat glands, sebaceous glands, arrector pili muscles, and arterioles. Autonomic input will induce functions like thermoregulation (such as vasodilation and sweat production) and “goosebumps” brought about by contraction of the arrector pili muscles.
The nerves of the skin form a branching plexus in the deeper layers of the reticular dermis, where the sensory receptors of the deeper layers are found and innervate structures such as the hair follicle and glands. Smaller nerve fibers extend up through the dermis to the papillary layer, forming a papillary plexus, where a variety of sensory receptors are found. Sensory receptors such as the free nerve endings will terminate in the epidermis, but the majority of nerve fibers do not extend this superficially (Standring, 2016).
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series: Elsevier Limited.
