Health Library Explorer
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z Listings Contact Us
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Click a letter to see a list of conditions beginning with that letter.
Click 'Topic Index' to return to the index for the current topic.
Click 'Library Index' to return to the listing of all topics.

Anatomy of the Skin

Facts about the skin

The skin is the body's largest organ. It covers the entire body. It serves as a protective shield against heat, light, injury, and infection. The skin also:

  • Regulates body temperature

  • Stores water and fat

  • Is a sensory organ

  • Prevents water loss

  • Prevents entry of bacteria

  • Acts as a barrier between the body and its environment

  • Helps to make vitamin D when exposed to the sun

Your skin takes on different thickness, color, and texture all over your body. For example, your head contains more hair follicles than anywhere else. But the soles of your feet have none. In addition, the soles of your feet and the palms of your hands are much thicker than skin on other areas of your body.

Cross section of skin showing epidermis, dermis and fat layer.

The skin is made up of 3 layers:

  • Epidermis

  • Dermis

  • Subcutaneous fat layer (hypodermis)

Each layer has certain functions.

Layer

What it does

Epidermis

The epidermis is the thin outer layer of the skin. It consists of 2 primary types of cells:

  • Keratinocytes. Keratinocytes comprise about 90% of the epidermis and are responsible for its structure and barrier functions.

  • Melanocytes. Melanocytes are found at the base of the epidermis and make melanin. This gives the skin its color.

Dermis

The dermis is the middle layer of the skin. The dermis contains:

  • Blood vessels

  • Lymph vessels

  • Hair follicles

  • Sweat glands

  • Collagen bundles

  • Fibroblasts

  • Nerves (pain, touch, and temperature receptors)

  • Sebaceous glands

The dermis is held together by a protein called collagen. This layer gives skin flexibility and strength.

Subcutaneous fat layer

The subcutaneous fat layer is the deepest layer of skin. It consists of a network of collagen and fat cells. It helps conserve the body's heat and protects the body from injury by acting as a shock absorber.

Online Medical Reviewer: L Renee Watson MSN RN
Online Medical Reviewer: Michael Lehrer MD
Online Medical Reviewer: Tennille Dozier RN BSN RDMS
Date Last Reviewed: 4/1/2023
© 2000-2024 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
Contact Our Health Professionals
Follow Us
Powered by StayWell
About StayWell | Disclaimer | Terms of Use

Our web site is designed to provide general information to educate users about programs and services, which may be available through our hospitals. The web site is not intended to provide medical advice nor should the information be used to attempt to determine the presence, absence or severity of any illness or medical condition which may be perceived or experienced by the user of this site. If you have or suspect you may have an illness or condition which you believe requires medical attention, we recommend you call your primary care physician. If you believe you are experiencing a medical emergency please call "911" (or your local medical emergency number) or seek immediate care from the nearest hospital Emergency Department. The provision of information to users of this web site is not intended as an inducement or to otherwise influence a person's decision to order or receive any item or service from a particular provider, practitioner or supplier that is reimbursable under Medicare, a state healthcare program (e.g., AHCCS) or any other healthcare plan.

Physicians are members of the medical staff at each facility, but are independent contractors who are neither employees nor agents of Tenet Florida Coastal Division; and, as a result, Tenet Florida Coastal Division is not responsible for the actions of any of these physicians in their medical practices.