Glossary of Integumentary System Terms and Terminology

  • Skin: The largest organ of the body that covers the entire body
  • The epidermis: The outermost layer of the skin that contains keratin and squamous epithelial cells
  • The dermis: The middle layer of the skin which gives the skin its elasticity and its ability to stretch
  • The hypodermis: The deepest layer of the skin, also referred to as the subcutaneous layer, stores fat
  • Subcutaneous level: An alternative name for the hypodermis which is the deepest layer of the skin
  • Thermoregulation: The regulation of the bodily temperature
  • Tactile sense: One of the 5 senses of the body that is the sense of touch
  • Hair: The fine and thick follicles that cover the vast majority of the human bodily surface
  • Finger and toe nails: These integumentary system structures protect the tips of the fingers and the toes.
  • Nail plate: The hard, strong and somewhat bendable surface of the nail and the part of the nail that is made of keratin.
  • Cuticles: Dead skin cells that are pushed over the peripheries of the nails at their base and around the edges.
  • Nail sinus: The base of the nail under the skin where the new nail tissue emerges from
  • Nail matrix: The tissue below the surface of the nail that is protected by its nail plate.
  • Nail bed: The skin that has three layers like other skin and is found below the entire nail plate
  • Lunula: The half-moon (luna) white area at the base of the nail.
  • Sebaceous glands: Exocrine glands that lubricate and moisturize the skin with an oily secretion which is called sebum
  • Sweat glands: As eccrine glands, sweat glands are found across the body and they secrete a substance that cools the body off with perspiration and they also eliminate some bodily wastes.
  • Acne: Also referred to as acne vulgaris, this is clogging of skin pores with dead skin and skin oils
  • Rash: An often itchy irregular reddened area on the skin that can occur from a number of different causes
  • Yeast infections: Infections of the skin
  • Athlete's foot: Also referred to as tinea pedis (foot), it is a fungal infection of the skin most often found on the feet
  • Pressure ulcer: Skin breakdown as the result of prolonged bed rest
  • Sunburn: Burning of the skin as the result of exposure to the sun
  • Skin cancer: Cancer occurring on one or more areas of the skin
  • Albinism: Defective melanin that causes an abnormal coloration of the skin and hair
  • Herpes: A viral infection
  • Herpes labialis: Also called cold sores, is a viral infection that typically affects the lips
  • Impetigo: A contagious skin condition that appears as a rash on the skin
  • Psoriasis: Thick skin on the skin surface as the result of an abnormal buildup of cells on the skin surface
  • Rosacea: A skin disorder that causes redness and skin break outs

The Role of the Integumentary System

The integumentary system consists of the skin, hair finger nails and toe nails and other structures including glands. Unlike the other bodily systems throughout the body, the integumentary system is not localized to one area or region of the body; instead the integumentary system covers the entire body.

The skin is by far the largest and most vast organ of the entire body.

The integumentary system plays several roles in the body including:

  • The protection of the body against the external environment. The skin is, for example, the first line of defense against germs and infections that are in the external environment outside of the body.
  • Temperature regulation. The skin, its thickness and its components, such as sweat glands, maintain the bodily temperature with little variation when the heat and cold of the environmental temperatures come in contact with it. The maintenance of bodily temperature is called thermoregulation.
  • Vitamin D production
  • Protection against harmful UV rays
  • The elimination of wastes through the pores with the process of perspiration, for example.
  • The prevention of bodily water losses and dehydration
  • The reception of tactile sensory messages such as heat, cold, and pain sensations such as a prick from a sharp object

The Parts of the Iintegumentary System

The integumentary system consists of the:

  • Skin
  • Hair
  • Finger and toe nails
  • Sebaceous glands
  • Sweat glands

The Skin

Cross-section of all skin layers.

The skin is the body's first line of defense against the threats in the environment that are external to the body.

The skin, as shown in the picture above, has several layers that include the following layers from the most exterior and upper level to the deepest most inner layer in that sequential order are:

  • The epidermis
  • The dermis
  • The hypodermis which is also referred to as the subcutaneous layer

The epidermis is avascular, which is defined as without blood vessels; the skin is comprised of squamous epithelial cells with the main type of cell being a cell that contains keratin which plays a role in the protection of the body and also prevents the skin from becoming water logged.

The dermis, the middle layer of the skin, contains blood vessels and it has two sublayers which are the reticular and papillary sublayers, both of which gives the skin its elasticity and its ability to stretch, such as occurs when there is swelling under the skin and when the abdominal area skin stretches during pregnancy.

The hypodermis, which is also referred to as the subcutaneous layer, is the fat storage layer of the skin. These fats, which are stored in the hypodermis, are ready for use and ready for the transport of this to cells when this energy is needed. This layer of skin with fat also maintains bodily temperature by serving as an insulator of the body.

The Hair

Cross section of a hair.

Section of skin, showing the epidermis and dermis; a hair in its follicle; the Arrector pili muscle; sebaceous glands.

Hair, like the fur of animals, plays a role in keeping the body warm. Additionally, the hair of the eye lashes protects the eyes from foreign debris getting into the eye from the external environment.

Hair covers the majority of the body surface; thick hair is found on the head and fine hair is found on other parts of the body such as the pubic area. Hair, as shown in the picture above, has a follicle, which is the part of the hair that is below the skin, and a shaft, which is the part of the hair that is above the skin. Hair, like skin and nails, contains keratin.

The Nails

The finger nails and toe nails of the body are also made of keratin like the hair and the skin. The three parts of the nail, as shown in the picture above, are the nail bed, the nail matrix and the nail plate. The fingernails and toenails protect the tips of our digits (finger tips and the tips of the toes) form injury.

The nails consist of several parts including the:

  • Nail plate
  • Cuticles
  • Nail sinus
  • Nail matrix
  • Nail bed
  • Lunula

The nail plate is the part of the nail that we typically refer to as a "nail"; however, technically, the nail plate is only one of several parts of the nail. The nail plate is the hard, strong and somewhat bendable surface of the nail and the part of the nail that is made of keratin. The nail plate makes up the majority of the nail that is seen with the naked eye.

The cuticles are dead skin cells that are pushed over the peripheries of the nails at their base and around the edges. Cuticles are removed during nail care and a manicure.

The nail sinus is the base of the nail under the skin where the new nail tissue emerges from.

The nail matrix is the tissue below the surface of the nail that is protected by its nail plate. This part of the nail, the nail matrix, will continue to grow infinitely until its nutrition and its blood supply are no longer adequate.

The nail bed is skin that has three layers like other skin. This skin is found below the entire nail plate.

The lunula, as the name suggests, is the half-moon (luna) white area at the base of the nail.

Sebaceous Glands

Schematic view of hair follicle and sebaceous gland.

Sebaceous glands, are exocrine glands, as contrasted to endocrine glands. Sebaceous glands lubricate and moisturize the skin with an oily secretion which is called sebum and the sebaceous glands also play minor roles in the thermoregulation of the body and its protective role that armors us against the invasion of infections because sebum is acidic and not an environment that germs thrive in.

The majority of sebaceous glands anatomically lie in the face and head, although sebaceous glands are found in all body surface areas which the exception of the palms and sole of the feet.

Sweat Glands

Sweat glands are eccrine and apocrine glands that secrete sweat to the surface of the skin.

Sweat glands, as apocrine glands, are found under the arms in the axillar area; they perform little function among humans. On the other hand, sweat glands, as eccrine glands and found across the body secrete a substance that cools the body off with perspiration and they eliminate some bodily wastes. Perspiration is a response to heat and stress and perspiration is a cooling off mechanism.

Disorders Affecting the Integumentary System

  • Acne
  • Rash
  • Yeast
  • Athlete's foot
  • Pressure ulcers
  • Infection
  • Sunburn
  • Skin cancer
  • Albinism
  • Herpes
  • Herpes labialis, commonly called cold sores
  • Impetigo
  • Psoriasis
  • Rosacea

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Alene Burke

Alene Burke

Alene Burke RN, MSN is a nationally recognized nursing educator. She began her work career as an elementary school teacher in New York City and later attended Queensborough Community College for her associate degree in nursing. She worked as a registered nurse in the critical care area of a local community hospital and, at this time, she was committed to become a nursing educator. She got her bachelor’s of science in nursing with Excelsior College, a part of the New York State University and immediately upon graduation she began graduate school at Adelphi University on Long Island, New York. She graduated Summa Cum Laude from Adelphi with a double masters degree in both Nursing Education and Nursing Administration and immediately began the PhD in nursing coursework at the same university. She has authored hundreds of courses for healthcare professionals including nurses, she serves as a nurse consultant for healthcare facilities and private corporations, she is also an approved provider of continuing education for nurses and other disciplines and has also served as a member of the American Nurses Association’s task force on competency and education for the nursing team members.
Alene Burke

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