Skip to main content
Biology LibreTexts

8.9: Glossary- The Integumentary System

  • Page ID
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    \( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)

    ( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\id}{\mathrm{id}}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\kernel}{\mathrm{null}\,}\)

    \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\)

    \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\)

    \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    \( \newcommand{\vectorA}[1]{\vec{#1}}      % arrow\)

    \( \newcommand{\vectorAt}[1]{\vec{\text{#1}}}      % arrow\)

    \( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vectorC}[1]{\textbf{#1}} \)

    \( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)

    \( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)

    \( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)

    \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    acne: skin condition due to infected sebaceous glands

    albinism: genetic disorder that affects the skin, in which there is no melanin production

    anagen: active phase of the hair growth cycle

    apocrine sweat gland: type of sweat gland that is associated with hair follicles in the armpits and genital regions

    arrector pili: smooth muscle that is activated in response to external stimuli that pull on hair follicles and make the hair “stand up”

    basal cell carcinoma: cancer that originates from basal cells in the epidermis of the skin

    basal cell: type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the keratinocytes of the epidermis

    bedsore: sore on the skin that develops when regions of the body start necrotizing due to constant pressure and lack of blood supply; also called decubitis ulcers

    callus: thickened area of skin that arises due to constant abrasion

    catagen: transitional phase marking the end of the anagen phase of the hair growth cycle

    corn: type of callus that is named for its shape and the elliptical motion of the abrasive force

    cortex: in hair, the second or middle layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb

    cuticle: in hair, the outermost layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb

    dermal papilla: (plural = dermal papillae) extension of the papillary layer of the dermis that increases surface contact between the epidermis and dermis

    dermis: layer of skin between the epidermis and hypodermis, composed mainly of connective tissue and containing blood vessels, hair follicles, sweat glands, and other structures

    desmosome: structure that forms an impermeable junction between cells

    eccrine sweat gland: type of sweat gland that is common throughout the skin surface; it produces a hypotonic sweat for thermoregulation

    eczema: skin condition due to an allergic reaction, which resembles a rash

    elastin fibers: fibers made of the protein elastin that increase the elasticity of the dermis

    eleiden: clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent water loss

    epidermis: outermost tissue layer of the skin

    eponychium: nail fold that meets the proximal end of the nail body, also called the cuticle

    external root sheath: outer layer of the hair follicle that is an extension of the epidermis, which encloses the hair root

    first-degree burn: superficial burn that injures only the epidermis

    fourth-degree burn: burn in which full thickness of the skin and underlying muscle and bone is damaged

    glassy membrane: layer of connective tissue that surrounds the base of the hair follicle, connecting it to the dermis

    hair bulb: structure at the base of the hair root that surrounds the dermal papilla

    hair follicle: cavity or sac from which hair originates

    hair matrix: layer of basal cells from which a strand of hair grows

    hair papilla: mass of connective tissue, blood capillaries, and nerve endings at the base of the hair follicle

    hair root: part of hair that is below the epidermis anchored to the follicle

    hair shaft: part of hair that is above the epidermis but is not anchored to the follicle

    hair: keratinous filament growing out of the epidermis

    hypodermis: connective tissue connecting the integument to the underlying bone and muscle

    hyponychium: thickened layer of stratum corneum that lies below the free edge of the nail

    integumentary system: skin and its accessory structures

    internal root sheath: innermost layer of keratinocytes in the hair follicle that surround the hair root up to the hair shaft

    keloid: type of scar that has layers raised above the skin surface

    keratin: type of structural protein that gives skin, hair, and nails its hard, water-resistant properties

    keratinocyte: cell that produces keratin and is the most predominant type of cell found in the epidermis

    keratohyalin: granulated protein found in the stratum granulosum

    Langerhans cell: specialized dendritic cell found in the stratum spinosum that functions as a macrophage

    lunula: basal part of the nail body that consists of a crescent-shaped layer of thick epithelium

    Meissner corpuscle: (also, tactile corpuscle) receptor in the skin that responds to light touch

    Merkel cell: receptor cell in the stratum basale of the epidermis that responds to the sense of touch

    medulla: in hair, the innermost layer of keratinocytes originating from the hair matrix

    melanin: pigment that determines the color of hair and skin

    melanocyte: cell found in the stratum basale of the epidermis that produces the pigment melanin

    melanoma: type of skin cancer that originates from the melanocytes of the skin

    melanosome: intercellular vesicle that transfers melanin from melanocytes into keratinocytes of the epidermis

    metastasis: spread of cancer cells from a source to other parts of the body

    nail bed: layer of epidermis upon which the nail body forms

    nail body: main keratinous plate that forms the nail

    nail cuticle: fold of epithelium that extends over the nail bed, also called the eponychium

    nail fold: fold of epithelium at that extend over the sides of the nail body, holding it in place

    nail root: part of the nail that is lodged deep in the epidermis from which the nail grows

    Pacinian corpuscle: (also, lamellated corpuscle) receptor in the skin that responds to vibration

    papillary layer: superficial layer of the dermis, made of loose, areolar connective tissue

    reticular layer: deeper layer of the dermis; it has a reticulated appearance due to the presence of abundant collagen and elastin fibers

    rickets: disease in children caused by vitamin D deficiency, which leads to the weakening of bones

    scar: collagen-rich skin formed after the process of wound healing that is different from normal skin

    sebaceous gland: type of oil gland found in the dermis all over the body and helps to lubricate and waterproof the skin and hair by secreting sebum

    sebum: oily substance that is composed of a mixture of lipids that lubricates the skin and hair

    second-degree burn: partial-thickness burn that injures the epidermis and a portion of the dermis

    squamous cell carcinoma: type of skin cancer that originates from the stratum spinosum of the epidermis

    stratum basale: deepest layer of the epidermis, made of epidermal stem cells

    stratum corneum: most superficial layer of the epidermis

    stratum granulosum: layer of the epidermis superficial to the stratum spinosum

    stratum lucidum: layer of the epidermis between the stratum granulosum and stratum corneum, found only in thick skin covering the palms, soles of the feet, and digits

    stratum spinosum: layer of the epidermis superficial to the stratum basale, characterized by the presence of desmosomes

    stretch mark: mark formed on the skin due to a sudden growth spurt and expansion of the dermis beyond its elastic limits

    sudoriferous gland: sweat gland

    telogen: resting phase of the hair growth cycle initiated with catagen and terminated by the beginning of a new anagen phase of hair growth

    third-degree burn: burn that penetrates and destroys the full thickness of the skin (epidermis and dermis)

    vitamin D: compound that aids absorption of calcium and phosphates in the intestine to improve bone health

    vitiligo: skin condition in which melanocytes in certain areas lose the ability to produce melanin, possibly due an autoimmune reaction that leads to loss of color in patches

    Contributors and Attributions

    CC licensed content, Shared previously

    8.9: Glossary- The Integumentary System is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

    • Was this article helpful?