[libribook.com] Traumatic Scar Tissue Management 1st Edition

Dermis
The dermis is made up of layers of fibrous and elastic fibers (collagen and
elastin). Collagen supports and stabilizes while elastin allows for stretch and
absorbs tensile forces – collagen and elastin will be covered in greater detail
further on in this chapter.
The dermis is often described as the workhorse of the skin because it contains
lymph vessels, nerve endings, sweat glands, sebaceous glands, hair follicles, and
blood vessels.
Nerve endings in skin sense pain, touch, pressure and temperature and relay
information to the brain (Kiernan & Rajakumar 2013, Bordoni & Zanier 2014).
Mechanoreceptors in skin provide information on posture, positioning and
movement (Macefield 2005, Bordoni & Zanier 2014, Mouchnino & Blouin
2013). As with all systems of the body, nerve receptors in skin and fascia can
evoke sympathetic nervous system (SNS) responses that can impact each other
and all the other systems.
The sweat glands produce sweat in response to heat and stress. Sweat is
composed mainly of water and salt. When sweat evaporates, it helps to cool the
body. There are specialized sweat glands in the armpits and the genital region
that secrete a thick, oily sweat that produces body odor when the sweat is
digested by the skin bacteria.
The sebaceous glands secrete oil called sebum into hair follicles. Sebum keeps
the skin moist and pliable and helps create a barrier against foreign substances.
The hair follicles produce various types of hair found throughout the body. Hair
contributes to a person’s appearance, helps regulate body temperature, provides
protection from injury and enhances sensation. At the base of each hair follicle
are sensory nerve fibers that wrap around the hair bulb. Moving or bending the
hair stimulates the nerve endings, which allow a person to feel their hair has
been moved. A portion of the follicle also contains stem cells capable of
regenerating a damaged epidermis.
Functions of the skin: Summary