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| [[Integumentary System Development|Integumentary Development]]
| [[Integumentary System Development|Integumentary Development]]
* '''acrosyringium''' -  coiled intra-epidermal region of the eccrine gland sweat duct.
* '''acrosyringium''' -  coiled intra-epidermal region of the eccrine gland sweat duct.
* '''apocrine gland''' - (sweat gland) proteinaceous secretion associated with hair (axilla, areola, genital and anal regions). Additional glands associated with eyelashes are called the glands of Moll (ciliary gland). (More? [[:File:Apocrine secretion animation.gif|image - apocrine secretion]])
* '''apocrine gland''' - (sweat gland) proteinaceous secretion associated with hair (axilla, areola, genital and anal regions). Additional glands associated with eyelashes are called the glands of Moll (ciliary gland). (More? [[:File:Apocrine secretion animation.gif|image - apocrine secretion]])
* '''arrector pili muscle''' - bundle of smooth muscle associated with hair follicle, inserts into the papillary layer of the dermis and attaches to the dermal sheath of the hair follicle. (More? [[:File:Integumentary- hair follicle 03.jpg|image - arrector pili muscle]])
* '''arrector pili muscle''' - bundle of smooth muscle associated with hair follicle, inserts into the papillary layer of the dermis and attaches to the dermal sheath of the hair follicle. (More? [[:File:Integumentary- hair follicle 03.jpg|image - arrector pili muscle]])
* '''Blaschko lines''' - (lines of Blaschko) may represent pathways of epidermal cell migration and proliferation during development. Specific type of lupus erythematosus shows this distinctive pattern. Named after Alfred Blaschko a German dermatologist who first described the feature in 1901. (More? [https://www.ncbi.nlm.nih.gov/pubmed/21396561 PMID 21396561] | [[Embryology Historic Terminology|Historic Terminology]])
* '''bulb''' - the hair follicle enlargement located at its deepest end, dividing cells form the hair and the root sheath.
* '''bulb''' - the hair follicle enlargement located at its deepest end, dividing cells form the hair and the root sheath.
* <span id="Term-café-aut-lait">'''café-aut-lait macule'''</span> - (French, ''cafe-au-lait'' = coffee with milk; birthmark) describes the characteristic colour of the skin hyperpigmented patch present at birth (congenital) or appearing in early infancy. Common single feature, multiple are associated with various genetic syndromes including Neurofibromatosis type 1 and 2.
* <span id="Term-café-aut-lait">'''café-aut-lait macule'''</span> - (French, ''cafe-au-lait'' = coffee with milk; birthmark) describes the characteristic colour of the skin hyperpigmented patch present at birth (congenital) or appearing in early infancy. Common single feature, multiple are associated with various genetic syndromes including Neurofibromatosis type 1 and 2.
* '''columnar''' - cells are longer than they are wide. (More? [[:File:Epithelium histology cartoon 01.jpg|image - cell shapes]])
* '''columnar''' - cells are longer than they are wide. (More? [[:File:Epithelium histology cartoon 01.jpg|image - cell shapes]])
* '''corneocytes''' - terminally differentiated keratinocytes forming the stratum corneum.
* '''corneocytes''' - terminally differentiated keratinocytes forming the stratum corneum.
* '''cuboidal''' - cells are about the same length and width. (More? [[:File:Epithelium histology cartoon 01.jpg|image - cell shapes]])
* '''cuboidal''' - cells are about the same length and width. (More? [[:File:Epithelium histology cartoon 01.jpg|image - cell shapes]])
* '''cutis''' - alternative term for the epidermis and the dermis layers of the skin.
* '''cutis''' - alternative term for the epidermis and the dermis layers of the skin.
* '''dermal papillae''' - interdigitation of the dermis with the epidermis.
* '''dermal papillae''' - interdigitation of the dermis with the epidermis.
* '''dermatoglyphic patterns''' - (Greek, ''derma'' = "skin", ''glyph'' = "carving") fingers, palms, toes, and soles skin patterns.
* '''dermis''' -  connective tissue middle layer of the skin, consists of two sublayers (papillary and reticular layers) that do not have a clear boundary. Embryologically derived from the somite dermatome.
* '''dermis''' -  connective tissue middle layer of the skin, consists of two sublayers (papillary and reticular layers) that do not have a clear boundary. Embryologically derived from the somite dermatome.
* '''dermatome''' - The early embryonic dorsal portion of the somite that will contribute the dermis and hypodermis of the skin. Note in the adult, this term is used to the skin sensory region innervated by a single spinal (nerve) segment. [[M#mesoderm|mesoderm]] - paraxial mesoderm - somite - dermomyotome - dermatome - dermis. (More? [[:File:Dermatomes.png|image - skin dermatome]] | [[Somitogenesis]] | [[Musculoskeletal System Development]] | [[Integumentary System Development]] | [[Neural System Development]])
* '''dermomyotome''' - Early embryonic dorsolateral half of the somite that will later divide to form both the dermatome and myotome. The dermatome will contribute the dermis and hypodermis of the skin. The myotome will contribute the skeletal muscle of muscoloskeletal system. Development sequence: [[M#mesoderm|mesoderm]] to paraxial mesoderm to somite to "dermomyotome" then  dermatome and myotome. (More? [[Somitogenesis]] | [[Musculoskeletal System Development]] | [[Integumentary System Development]])
* '''dermomyotome''' - Early embryonic dorsolateral half of the somite that will later divide to form both the dermatome and myotome. The dermatome will contribute the dermis and hypodermis of the skin. The myotome will contribute the skeletal muscle of muscoloskeletal system. Development sequence: [[M#mesoderm|mesoderm]] to paraxial mesoderm to somite to "dermomyotome" then  dermatome and myotome. (More? [[Somitogenesis]] | [[Musculoskeletal System Development]] | [[Integumentary System Development]])
* '''dermatome''' - The early embryonic dorsal portion of the somite that will contribute the dermis and hypodermis of the skin. Note in the adult, this term is used to the skin sensory region innervated by a single spinal (nerve) segment. [[M#mesoderm|mesoderm]] - paraxial mesoderm - somite - dermomyotome - dermatome - dermis. (More? [[:File:Dermatomes.png|image - skin dermatome]] | [[Somitogenesis]] | [[Musculoskeletal System Development]] | [[Integumentary System Development]] | [[Neural System Development]])
 
* '''eccrine gland''' (Greek, ''ekkrinein'' = "secrete"; merocrine glands) sweat glands unique to some primates and used in humans for thermoregulation. Adult body has 2 to 4 million sweat glands with concentrations (700/cm) on the palms of the hand, soles of the feet and forehead. Secretion is timulated by sympathetic nervous system, post-ganglionic cholinergic branch, and other stimuli
* '''eccrine gland''' (Greek, ''ekkrinein'' = "secrete"; merocrine glands) sweat glands unique to some primates and used in humans for thermoregulation. Adult body has 2 to 4 million sweat glands with concentrations (700/cm) on the palms of the hand, soles of the feet and forehead. Secretion is timulated by sympathetic nervous system, post-ganglionic cholinergic branch, and other stimuli
* <span id="Term-ephilis">'''ephilis'''</span> - (pl., ephilides; freckle) Clinical term describing a "freckle", that is a small brown or tan mark on the skin. These inherited features result from a copy of variant Melanocortin 1 Receptor (MC1R) gene and are common on fair skinned Celtic children. Melanocytes produce locally more melanin, this can also increase following exposure to ultraviolet radiation in sunlight. (More? [[Integumentary System Development|Integumentary]] | [[Neural Crest Development|Neural Crest]] | [http://www.omim.org/entry/155555 OMIM MC1R])
* <span id="Term-ephilis">'''ephilis'''</span> - (pl., ephilides; freckle) Clinical term describing a "freckle", that is a small brown or tan mark on the skin. These inherited features result from a copy of variant Melanocortin 1 Receptor (MC1R) gene and are common on fair skinned Celtic children. Melanocytes produce locally more melanin, this can also increase following exposure to ultraviolet radiation in sunlight. (More? [[Integumentary System Development|Integumentary]] | [[Neural Crest Development|Neural Crest]] | [http://www.omim.org/entry/155555 OMIM MC1R])
* <span id="Term-epidermis">'''epidermis'''</span> - Histological term describing the external cellular epithelial layer of the integumentary (skin) covering the entire body. This surface layer of keratinocytes is [[E#ectoderm|ectoderm]] in origin, while the underlying connective tissue layers of [[D#dermis|dermis]] and [[H#hypodermis|hypodermis]] are [[M#mesoderm|mesoderm]] in origin. (More? [[Integumentary Development]])
* <span id="Term-epidermis">'''epidermis'''</span> - Histological term describing the external cellular epithelial layer of the integumentary (skin) covering the entire body. This surface layer of keratinocytes is [[E#ectoderm|ectoderm]] in origin, while the underlying connective tissue layers of [[D#dermis|dermis]] and [[H#hypodermis|hypodermis]] are [[M#mesoderm|mesoderm]] in origin. (More? [[Integumentary Development]])
* <span id="Term-EDC">'''epidermal differentiation complex'''</span> - (EDC) human chromosome (1q2) containing linked 63 genes within four gene families  that are molecular markers for stratified epidermis terminal differentiation.
* <span id="Term-EDC">'''epidermal differentiation complex'''</span> - (EDC) human chromosome (1q2) containing linked 63 genes within four gene families  that are molecular markers for stratified epidermis terminal differentiation.
* <span id="Term-EGFR">'''epidermal growth factor receptor'''</span> - expressed on cells in the epidermis basal layer, signaling stimulates both epidermal growth and wound healing and also mediates an inhibition of differentiation.
* <span id="Term-freckle">'''freckle'''</span> - See [[#ephilis|ephilis]].
* <span id="Term-freckle">'''freckle'''</span> - See [[#ephilis|ephilis]].
* <span id="Term-glabrous_skin">'''glabrous skin'''</span> - skin without hair, refers to the palms of hands and soles of feet.
* '''hair''' - (pili) in humans consists of vellus and terminal hairs.
* '''hair''' - (pili) in humans consists of vellus and terminal hairs.
* '''holocrine''' - form of gland secretion where the secretory cells eventually lyse (rupture) and are lost. On the skin, these cells release sebum consisting mainly of lipid. (More? [[:File:Holocrine secretion animation.gif|image - holocrine secretion]])
* '''holocrine''' - form of gland secretion where the secretory cells eventually lyse (rupture) and are lost. On the skin, these cells release sebum consisting mainly of lipid. (More? [[:File:Holocrine secretion animation.gif|image - holocrine secretion]])
* '''hypodermis''' -  (subcutis) connective tissue inner layer of the skin that binds it to underlying structures.
 
* '''hypodermis''' -  (subcutis, subcutaneous adipose) a connective tissue ilower layer of the skin that binds it to underlying structures.
 
* '''integumentary''' - term for the skin and its appendages.
* '''integumentary''' - term for the skin and its appendages.
* '''involucrin'''  - protein that binds loricrin in the development of the cell envelope protecting corneocytes in the skin.
* '''involucrin'''  - protein that binds loricrin in the development of the cell envelope protecting corneocytes in the skin.
* <span id="Term-keratinocyte">'''keratinocyte'''</span> - the main cell type forming the layers of the epidermis, derived from ectoderm.
* '''keratohyalin granule''' - found in the stratum granulosum consist of profilaggrin and loricrin.
* '''Langerhans cell''' - skin dendritic cell (antigen presenting cell) develops initially from fetal liver monocytes and yolk sac macrophages. May, depending on the immunological setting, elicit immunity or tolerance. Named after Paul Langerhans.
* '''Langerhans cell''' - skin dendritic cell (antigen presenting cell) develops initially from fetal liver monocytes and yolk sac macrophages. May, depending on the immunological setting, elicit immunity or tolerance. Named after Paul Langerhans.
* '''keratinocyte''' - the main cell type forming the layers of the epidermis, derived from ectoderm.
 
* '''keratohyalin granule''' - found in the stratum granulosum consist of profilaggrin and loricrin.
* '''Langer's lines''' - (skin cleavage lines, cleavage lines) Clinical term for the orientation of reticular dermis collagen bundles causing tensions on skin and subcutaneous tissues. Lines tend to be horizontal in the trunk and neck, and longitudinal in the skin and limbs. (More? [https://www.ncbi.nlm.nih.gov/pubmed/15791423 PMID 15791423])
 
* '''Meissner corpuscle''' - sensory structure acting as a rapidly-adapting mechanoreceptor mainly in the dermal papillae of (digital) skin. (More?[[Sensory - Touch Development|Touch]]
* '''Meissner corpuscle''' - sensory structure acting as a rapidly-adapting mechanoreceptor mainly in the dermal papillae of (digital) skin. (More?[[Sensory - Touch Development|Touch]]
* '''melanin''' - (Greek, ''melanos'' = black) The pigment produced by [[M#melanocyte|melanocytes]] that provides photoprotection, preventing cellular DNA damage, and colouring of the basal epithelial cells that  absorb the pigment.
* '''melanin''' - (Greek, ''melanos'' = black) The pigment produced by [[M#melanocyte|melanocytes]] that provides photoprotection, preventing cellular DNA damage, and colouring of the basal epithelial cells that  absorb the pigment.
* '''melanodermia''' -  hyperpigmentation causing abnormal darkening (brown/black) of the skin due to excess melanin or by metallic substances. See also the abnormality ceruloderma (blue/grey). (More? PMID 23522626)
 
* '''melanodermia''' -  hyperpigmentation causing abnormal darkening (brown/black) of the skin due to excess melanin or by metallic substances. See also the abnormality ceruloderma (blue/grey). (More? [https://www.ncbi.nlm.nih.gov/pubmed/23522626 PMID 23522626])
 
*''' melanoblast''' - (Greek, ''melanos'' = black) The [[N#neural crest|neural crest]] precursor cell that differentiates to form [[M#melanocyte|melanocytes]] located in the skin and other tissues that produces [[M#melanin|melanin]]. (More? [[Neural Crest Development]] | [[Integumentary System Development]])
*''' melanoblast''' - (Greek, ''melanos'' = black) The [[N#neural crest|neural crest]] precursor cell that differentiates to form [[M#melanocyte|melanocytes]] located in the skin and other tissues that produces [[M#melanin|melanin]]. (More? [[Neural Crest Development]] | [[Integumentary System Development]])
* '''melanocyte''' - (Greek, ''melanos'' = black) A pigmented cell, [[N#neural crest|neural crest]] in origin, differentiating from [[M#melanoblast|melanoblasts]] located in the skin and other tissues that produces [[M#melanin|melanin]]. The melanocytes within the integument (skin) transfer melanin to keratinocytes to give skin colour and to the hair follicle to give hair colour. Melanocytes are also located within "non-cutaneous" tissues in the eye (for eye colour), [[H#harderian gland|harderian gland]] and inner ear. This is the cell type that proliferates in the cancer melanoma. (More? [[Neural Crest Development]] | [[Integumentary System Development]])
* '''melanocyte''' - (Greek, ''melanos'' = black) A pigmented cell, [[N#neural crest|neural crest]] in origin, differentiating from [[M#melanoblast|melanoblasts]] located in the skin and other tissues that produces [[M#melanin|melanin]]. The melanocytes within the integument (skin) transfer melanin to keratinocytes to give skin colour and to the hair follicle to give hair colour. Melanocytes are also located within "non-cutaneous" tissues in the eye (for eye colour), [[H#harderian gland|harderian gland]] and inner ear. This is the cell type that proliferates in the cancer melanoma. (More? [[Neural Crest Development]] | [[Integumentary System Development]])
* '''Merkel cell''' - An epidermal-derived cell in touch-sensitive area of the epidermis and mediate mechanotransduction in the skin. Previously thought to be neural crest in origin, but recently shown to arise from the embryonic epithelium. The cells are named after Friedrich Sigmund Merkel, a German anatomist who was the first to describe them in 1875. (More? [[Sensory - Touch Development|Touch]] | [[Lecture - Integumentary Development]] |  PMID 19786578 | PMID 3782861)
 
* '''Merkel cell''' - An epidermal-derived cell in touch-sensitive area of the epidermis and mediate mechanotransduction in the skin. Previously thought to be neural crest in origin, but recently shown to arise from the embryonic epithelium. The cells are named after Friedrich Sigmund Merkel, a German anatomist who was the first to describe them in 1875. (More? [[Sensory - Touch Development|Touch]] | [[Lecture - Integumentary Development]] |  [https://www.ncbi.nlm.nih.gov/pubmed/19786578 PMID 19786578] | [https://www.ncbi.nlm.nih.gov/pubmed/3782861 PMID 3782861])
 
* '''merocrine gland'''  - (sweat gland, eccrine sweat) simple tubular glands located at the border between the dermis and hypodermis. These glands regulate the body temperature.  (More? [[:File:Merocrine secretion animation.gif|image - merocrine secretion]])
* '''merocrine gland'''  - (sweat gland, eccrine sweat) simple tubular glands located at the border between the dermis and hypodermis. These glands regulate the body temperature.  (More? [[:File:Merocrine secretion animation.gif|image - merocrine secretion]])
* '''nestin''' - (neuroectodermal stem cell marker) an intermediate filament protein (type VI) expressed in stem cells and transiently during development, and in cells within hair follicles, sebaceous and sweat glands.
* '''nestin''' - (neuroectodermal stem cell marker) an intermediate filament protein (type VI) expressed in stem cells and transiently during development, and in cells within hair follicles, sebaceous and sweat glands.
* '''papillary layer''' - dermis sublayer that appears less dense and contains more cells lying close beneath the epidermis.  (More? [[:File:Adult skin histology 04.jpg|image]])
* '''papillary layer''' - dermis sublayer that appears less dense and contains more cells lying close beneath the epidermis.  (More? [[:File:Adult skin histology 04.jpg|image]])
* '''pilosebaceous unit''' - term used to describe a hair and its associated structures: hair follicle, arrector pili muscle and sebaceous gland.
* '''pilosebaceous unit''' - term used to describe a hair and its associated structures: hair follicle, arrector pili muscle and sebaceous gland.
* <span id="Term-rete_ridge">'''rete ridge'''</span> -  the extensions of the epidermis into the dermis. These epidermal surface thickenings extend downward between underlying connective tissue dermal papillae. This is also the site of initial eccrine gland differentiation.
* '''reticular layer''' -  dermis sublayer that appears denser and contains fewer cells with thick collagen bundles lying beneath the papillary layer parallel to the skin surface.  (More? [[:File:Adult skin histology 04.jpg|image]])
* '''reticular layer''' -  dermis sublayer that appears denser and contains fewer cells with thick collagen bundles lying beneath the papillary layer parallel to the skin surface.  (More? [[:File:Adult skin histology 04.jpg|image]])
* '''root sheath''' - cell layers that surround the hair.
* '''root sheath''' - cell layers that surround the hair.
* '''sebaceous gland''' - holocrine gland associated with both the hair follicle and hairless parts of the skin (lips, cheek oral surface and external genitalia). Embedded in the dermis and are sites of infections (acne).
* '''sebaceous gland''' - holocrine gland associated with both the hair follicle and hairless parts of the skin (lips, cheek oral surface and external genitalia). Embedded in the dermis and are sites of infections (acne).
* '''simple''' - consisting of a single cell layer.
* '''simple''' - consisting of a single cell layer.
* '''squamous''' - flattened, used to describe epithelia where the upper cell layer shape is flattened.  (More? [[:File:Epithelium histology cartoon 01.jpg|image - cell shapes]] | [[:File:Epidermis cartoon 01.jpg|image - squamous epithelium]])
* '''squamous''' - flattened, used to describe epithelia where the upper cell layer shape is flattened.  (More? [[:File:Epithelium histology cartoon 01.jpg|image - cell shapes]] | [[:File:Epidermis cartoon 01.jpg|image - squamous epithelium]])
* '''stratified''' - consisting of several cell layers.  (More? [[:File:Epidermis cartoon 01.jpg|image - stratified epithelium]])
* '''stratified''' - consisting of several cell layers.  (More? [[:File:Epidermis cartoon 01.jpg|image - stratified epithelium]])
* '''terminal hairs''' - hair seen in obviously hairy parts of the body.
* '''terminal hairs''' - hair seen in obviously hairy parts of the body.
* '''thick skin''' - refers to the skin histology found on the palms of the hand and soles of the feet, do not contain hair. Note that this is used as a histological term not a measurement of overall skin thickness.
 
* '''thin skin''' - refers to the skin histology found on skin in all other regions beside palms and soles.
* '''thick skin''' - refers to the skin histology found on the palms of the hand and soles of the feet, does not contain hair. Note that this is used as a histological term not a measurement of overall skin thickness.
 
* '''thin skin''' - refers to the skin histology found on skin on all body regions, other than palms and soles (thick skin).
 
* '''vellus hairs''' - fine short hairs only lightly pigmented covering the body.
* '''vellus hairs''' - fine short hairs only lightly pigmented covering the body.
* '''vernix caseosa''' - (vernix, Latin, "caseosa" = cheese-like) a fetal protective coating consisting of sebum, skin cells and lanugo hair. Forming late in fetal development in a rostra-caudal sequence associated with epithelium differentiation.
* '''vernix caseosa''' - (vernix, Latin, "caseosa" = cheese-like) a fetal protective coating consisting of sebum, skin cells and lanugo hair. Forming late in fetal development in a rostra-caudal sequence associated with epithelium differentiation.
* '''Voigt's lines''' - clinical term to describe the skin borders between areas of innervations by specific peripheral cutaneous nerves. (More? [[Sensory_-_Touch_Development|Sensory Touch]] | [[Embryology Historic Terminology|Historic Terminology]])
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Latest revision as of 14:09, 9 October 2017

Integumentary Terms  
Integumentary Development
  • acrosyringium - coiled intra-epidermal region of the eccrine gland sweat duct.
  • apocrine gland - (sweat gland) proteinaceous secretion associated with hair (axilla, areola, genital and anal regions). Additional glands associated with eyelashes are called the glands of Moll (ciliary gland). (More? image - apocrine secretion)
  • arrector pili muscle - bundle of smooth muscle associated with hair follicle, inserts into the papillary layer of the dermis and attaches to the dermal sheath of the hair follicle. (More? image - arrector pili muscle)
  • Blaschko lines - (lines of Blaschko) may represent pathways of epidermal cell migration and proliferation during development. Specific type of lupus erythematosus shows this distinctive pattern. Named after Alfred Blaschko a German dermatologist who first described the feature in 1901. (More? PMID 21396561 | Historic Terminology)
  • bulb - the hair follicle enlargement located at its deepest end, dividing cells form the hair and the root sheath.
  • café-aut-lait macule - (French, cafe-au-lait = coffee with milk; birthmark) describes the characteristic colour of the skin hyperpigmented patch present at birth (congenital) or appearing in early infancy. Common single feature, multiple are associated with various genetic syndromes including Neurofibromatosis type 1 and 2.
  • corneocytes - terminally differentiated keratinocytes forming the stratum corneum.
  • cutis - alternative term for the epidermis and the dermis layers of the skin.
  • dermal papillae - interdigitation of the dermis with the epidermis.
  • dermatoglyphic patterns - (Greek, derma = "skin", glyph = "carving") fingers, palms, toes, and soles skin patterns.
  • dermis - connective tissue middle layer of the skin, consists of two sublayers (papillary and reticular layers) that do not have a clear boundary. Embryologically derived from the somite dermatome.
  • dermomyotome - Early embryonic dorsolateral half of the somite that will later divide to form both the dermatome and myotome. The dermatome will contribute the dermis and hypodermis of the skin. The myotome will contribute the skeletal muscle of muscoloskeletal system. Development sequence: mesoderm to paraxial mesoderm to somite to "dermomyotome" then dermatome and myotome. (More? Somitogenesis | Musculoskeletal System Development | Integumentary System Development)
  • eccrine gland (Greek, ekkrinein = "secrete"; merocrine glands) sweat glands unique to some primates and used in humans for thermoregulation. Adult body has 2 to 4 million sweat glands with concentrations (700/cm) on the palms of the hand, soles of the feet and forehead. Secretion is timulated by sympathetic nervous system, post-ganglionic cholinergic branch, and other stimuli
  • ephilis - (pl., ephilides; freckle) Clinical term describing a "freckle", that is a small brown or tan mark on the skin. These inherited features result from a copy of variant Melanocortin 1 Receptor (MC1R) gene and are common on fair skinned Celtic children. Melanocytes produce locally more melanin, this can also increase following exposure to ultraviolet radiation in sunlight. (More? Integumentary | Neural Crest | OMIM MC1R)
  • epidermis - Histological term describing the external cellular epithelial layer of the integumentary (skin) covering the entire body. This surface layer of keratinocytes is ectoderm in origin, while the underlying connective tissue layers of dermis and hypodermis are mesoderm in origin. (More? Integumentary Development)
  • epidermal differentiation complex - (EDC) human chromosome (1q2) containing linked 63 genes within four gene families that are molecular markers for stratified epidermis terminal differentiation.
  • epidermal growth factor receptor - expressed on cells in the epidermis basal layer, signaling stimulates both epidermal growth and wound healing and also mediates an inhibition of differentiation.
  • glabrous skin - skin without hair, refers to the palms of hands and soles of feet.
  • hair - (pili) in humans consists of vellus and terminal hairs.
  • holocrine - form of gland secretion where the secretory cells eventually lyse (rupture) and are lost. On the skin, these cells release sebum consisting mainly of lipid. (More? image - holocrine secretion)
  • hypodermis - (subcutis, subcutaneous adipose) a connective tissue ilower layer of the skin that binds it to underlying structures.
  • integumentary - term for the skin and its appendages.
  • involucrin - protein that binds loricrin in the development of the cell envelope protecting corneocytes in the skin.
  • keratinocyte - the main cell type forming the layers of the epidermis, derived from ectoderm.
  • keratohyalin granule - found in the stratum granulosum consist of profilaggrin and loricrin.
  • Langerhans cell - skin dendritic cell (antigen presenting cell) develops initially from fetal liver monocytes and yolk sac macrophages. May, depending on the immunological setting, elicit immunity or tolerance. Named after Paul Langerhans.
  • Langer's lines - (skin cleavage lines, cleavage lines) Clinical term for the orientation of reticular dermis collagen bundles causing tensions on skin and subcutaneous tissues. Lines tend to be horizontal in the trunk and neck, and longitudinal in the skin and limbs. (More? PMID 15791423)
  • Meissner corpuscle - sensory structure acting as a rapidly-adapting mechanoreceptor mainly in the dermal papillae of (digital) skin. (More?Touch
  • melanin - (Greek, melanos = black) The pigment produced by melanocytes that provides photoprotection, preventing cellular DNA damage, and colouring of the basal epithelial cells that absorb the pigment.
  • melanodermia - hyperpigmentation causing abnormal darkening (brown/black) of the skin due to excess melanin or by metallic substances. See also the abnormality ceruloderma (blue/grey). (More? PMID 23522626)
  • melanocyte - (Greek, melanos = black) A pigmented cell, neural crest in origin, differentiating from melanoblasts located in the skin and other tissues that produces melanin. The melanocytes within the integument (skin) transfer melanin to keratinocytes to give skin colour and to the hair follicle to give hair colour. Melanocytes are also located within "non-cutaneous" tissues in the eye (for eye colour), harderian gland and inner ear. This is the cell type that proliferates in the cancer melanoma. (More? Neural Crest Development | Integumentary System Development)
  • Merkel cell - An epidermal-derived cell in touch-sensitive area of the epidermis and mediate mechanotransduction in the skin. Previously thought to be neural crest in origin, but recently shown to arise from the embryonic epithelium. The cells are named after Friedrich Sigmund Merkel, a German anatomist who was the first to describe them in 1875. (More? Touch | Lecture - Integumentary Development | PMID 19786578 | PMID 3782861)
  • merocrine gland - (sweat gland, eccrine sweat) simple tubular glands located at the border between the dermis and hypodermis. These glands regulate the body temperature. (More? image - merocrine secretion)
  • nestin - (neuroectodermal stem cell marker) an intermediate filament protein (type VI) expressed in stem cells and transiently during development, and in cells within hair follicles, sebaceous and sweat glands.
  • papillary layer - dermis sublayer that appears less dense and contains more cells lying close beneath the epidermis. (More? image)
  • pilosebaceous unit - term used to describe a hair and its associated structures: hair follicle, arrector pili muscle and sebaceous gland.
  • rete ridge - the extensions of the epidermis into the dermis. These epidermal surface thickenings extend downward between underlying connective tissue dermal papillae. This is also the site of initial eccrine gland differentiation.
  • reticular layer - dermis sublayer that appears denser and contains fewer cells with thick collagen bundles lying beneath the papillary layer parallel to the skin surface. (More? image)
  • root sheath - cell layers that surround the hair.
  • sebaceous gland - holocrine gland associated with both the hair follicle and hairless parts of the skin (lips, cheek oral surface and external genitalia). Embedded in the dermis and are sites of infections (acne).
  • simple - consisting of a single cell layer.
  • terminal hairs - hair seen in obviously hairy parts of the body.
  • thick skin - refers to the skin histology found on the palms of the hand and soles of the feet, does not contain hair. Note that this is used as a histological term not a measurement of overall skin thickness.
  • thin skin - refers to the skin histology found on skin on all body regions, other than palms and soles (thick skin).
  • vellus hairs - fine short hairs only lightly pigmented covering the body.
  • vernix caseosa - (vernix, Latin, "caseosa" = cheese-like) a fetal protective coating consisting of sebum, skin cells and lanugo hair. Forming late in fetal development in a rostra-caudal sequence associated with epithelium differentiation.
  • Voigt's lines - clinical term to describe the skin borders between areas of innervations by specific peripheral cutaneous nerves. (More? Sensory Touch | Historic Terminology)
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