Online Guide to the Anatomy of Your Skin

The skin refers to the outer covering of the human body. It is the body’s largest organ, and it functions to protect all the internal components. There are generally two types of skin, namely, hairy skin and glabrous skin. Although the skin on some human beings appears to be hairless, it is mostly covered with hair follicles. Skin type can vary from oily to dry, and the pigmentation of skin differs among human populations.

Functions of the Skin

The human skin consists of several layers of cells, which work together to provide a wide range of benefits for the human body. The outer layer contains mesodermal cells and other substances that function to absorb detrimental ultraviolet radiation. Some cells in this layer will wear out during the course of the day, and they are constantly being replaced by new cells that are produced in the lower layers. When the skin sustains injuries, the exfoliation process will go into overdrive to help the skin heal. Other than protecting the internal components of the body, the skin also serves to provide sensation, regulate heat, control fluid loss, stores water, synthesizes vitamin D, removes toxins through perspiration, and absorbs medications such as ointments and medicinal patches.

  • The Human Skin: This web page contains extensive information on the human skin.
  • Your Skin: A document that provides a brief overview of the human skin.
  • The Integument: This document provides an excellent explanation of the integument system.
  • Unmasking Skin: An interesting article about the human skin by National Geographic.

Epidermis

The outermost layer of the skin is called the epidermis. This layer functions to protect the body from harmful elements and infections, as well as provide waterproofing. It is made up of three sub-layers, which are the stratum corneum, keratinocytes, and basal layer. The epidermis is mainly comprised of squamous cells and basal cells, and its deepest part contains melanocytes. Melanocytes are responsible for the production of melanin, a substance that determines the color of the skin.

  • Melanocytes: Read this document to gain a better understanding of melanocytes.

Dermis

The dermis lies just below the epidermis, and it contains a number of important components of the skin, such as blood and lymph vessels, glands, and hair follicles. Glands in the dermis serve to control body temperature by facilitating perspiration, and they also produce an oily substance called seburn to prevent drying of the skin. Sweat and seburn that are produced in the dermis rise to the surface of the skin through the pores.

  • What is Dermis?: A document that provides a concise summary of the composition and function of dermis. 

Subcutis

Subcutis is also commonly referred to as hypodermis, and it is the bottommost layer of the skin. It attaches the dermis to the underlying muscles and bones, and it supplies blood vessels and nerves to the skin. It is made up of connective tissue and elastin, and its main cell types include fibroblasts, adipocytes, and macrophages. It contains a lot of body fat, which provides insulation and padding for the body.

  • The Subcutis: This web page provides illustrated explanations of the construction and function of the subcutis.