Skin anatomy

1. [noun] source: Pintrist.jpg Accessed: Nov 1st 2019 Review this fantastic site which describes the anatomy and physiology of the skin in great detail. LINK: https://opentextbc.ca/anatomyandphysiology/chapter/5-1-layers-of-the-skin/ Go to chapter 5 Skin is the largest organ in the body which provides protection to the body. Along with the accessory structures it makes up the integumentary system. It consists of multiple layers of cells and tissues attached structures by connective tissue. Skin function: Provides protection Blood supply (deeper layer contains blood vessels) Sensory, autonomic and sympathetic nerve fibers which communicate with the nervous system Sweat glands Hair follicles Loose connective tissue Fatty tissue Skin consists of 3 layers: Epidermis Dermis Hypodermis 1. Epidermis - keratinized, stratified squamous epithelium. Thin skin: has 4 layers in the epidermis (stratum corneum, stratum granulosum, stratum spinosum, and stratum basale) Thick skin : has 5 layers in the epidermis and is only found on the palms of the hands and soles of the feet. (stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale) Keratinocyte cells : Produce and store keratin. The keratinocytes are found in all of the layers except for the stratum basale layer. Keratin gives hair, nails and skin, structure and water-resistance. The keratinocyte cells in the corneum layer are dead cells and are sloughed off and replaced. Melanocytes cells : are cells in the epidermis that product skin pigment (color). 2. Dermis - Provides connective tissues, hair follicles, sweat glands, sebaceous (oil) glands, vascular supply, lymph vessels, and nerves. The dermis is made of two layers of connective tissues, the papillary and reticular layer. Papillary Layer: is loose connective tissue “mesh like” layer that has “finger like” projects into the stratum basale. The papillary layer has fibroblasts, some fat cells, blood vessels, touch receptors (Meissner corpuscles) and phagocytes. Phagocytes fight infection when the skin is breached. Houses nerve endings (corpuscles) providing the body with sense of touch, pain, heat, cold, pressure and touch. Papillae are small cone-shaped projections of elastic tissue that point upward and contain looped caillaries or nerve fiber endings Reticular Layer: located beneath the papillary layer, is a thick layer with a tight network of fibers including elastin fibers for elasticity of the skin. It is highly vascularized with an abundance of sensory and sympathetic nerve supply, as well as fat cells, lymph vessels, oil and sweat glands, hair follicles and arrector pili muscles. Elastin fibers provide structure, elasticity and movement to the skin. Collagen fibers provide structure and tensile strength. These fibers extend from the papillary layer to the hypodermis. Collagen binds water keeping the skin hydrated. 3. Hypodermis (subcutaneous or superficial fascia layer): is the deeper subcutaneous tissue layer which is highly vascular and consists of adipose tissue (fat) and connective tissue. The hypodermis is situated below the dermis and serves to connect the skin to the fascia beneath. The hypodermis layer functions as fat storage, insulation and cushioning protection. Review this fantastic site which describes the anatomy and physiology of the skin in great detail. LINK: https://opentextbc.ca/anatomyandphysiology/chapter/5-1-layers-of-the-skin/ Go to Chapter 5 Sources accessed Nov 17th 2019 1. Open text BC Anatomy and Physiology Chapter 5 2. Web MD 3. Anatomy of skin lecture: Slideshare.net

Source: https://open.umn.edu/opentextbooks/textbooks/anatomy-and-physiology-laboratory-manual-for-nursing-and-allied-health