Dermis

Information about Dermis

Dermis
The distribution of the bloodvessels in the skin of the sole of the foot. (Corium - TA alternate term for dermis - is labeled at upper right.)
A diagrammatic sectional view of the skin (magnified). (Dermis labeled at center right.)
subject #234 1065
MeSH Dermis
Dorlands/Elsevier d_11/12289496
The dermis is a layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many nerve endings that provide the sense of touch and heat. It contains the hair follicles, sweat glands, sebaceous glands, apocrine glands and blood vessels. The blood vessels in the dermis provide nourishment and waste removal to its own cells as well as the Stratum basale of the epidermis.

Structure

The dermis is structurally divided into two areas: a superficial area adjacent to the epidermis, called the papillary region, and a deep thicker area known as the reticular region.

Papillary region

The papillary region is composed of loose areolar connective tissue. It is named for its fingerlike projections called papillae, that extend toward the epidermis. The papillae provide the dermis with a "bumpy" surface that interdigitates with the epidermis, strengthening the connection between the two layers of skin.

In the palms, fingers, soles, and toes, the influence of the papillae projecting into the epidermis forms contours in the skin's surface. These are called friction ridges, because they help the hand or foot to grasp by increasing friction. Friction ridges occur in patterns (see fingerprint) that are genetically determined and are therefore unique to the individual, making it possible to use fingerprints or footprints as a means of identification.

Reticular region

The reticular region lies deep in the papillary region and is usually much thicker. It is composed of dense irregular connective tissue, and receives its name from the dense concentration of collagenous, elastic, and reticular fibers that weave throughout it. These protein fibers give the dermis its properties of strength, extensibility, and elasticity.

Located within the reticular region are also the hair roots, sebaceous glands, sweat glands, receptors, nails, and blood vessels.

Tattoo ink is injected into the dermis. Stretch marks are also located in the dermis.

Additional images


Cross-section of all skin layers.


External links

 •  • [ e]
Integumentary system
structuresSkin • Sweat glands • Sebaceous glands • Hair (Hair follicle) • Nails • Scale
layersEpidermis (Stratum corneum, Stratum lucidum, Stratum granulosum, Stratum spinosum, Stratum germinativum/basale) • Dermis • Subcutis
Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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Skin layers: epidermis, dermis, and subcutis, showing a hair follicle, sweat gland & sebaceous gland.]] In zootomy and dermatology, skin is the largest organ of the integumentary system made up of multiple layers of epithelial tissues that guard underlying muscles and organs.
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Epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the body's surface and is made up of stratified squamous epithelium with an underlying basal lamina.
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Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, muscle, and nervous tissue.) It is largely a category of exclusion rather than one with a precise definition, but all or most tissues in this category are similarly:
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basement membrane is a structure that supports overlying epithelial or endothelial cells.

Composition

The basement membrane consists of an electron-dense membrane called the lamina densa, about 30–70 nanometers in thickness, and an underlying network of reticular
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A hair follicle is part of the skin that grows hair by packing old cells together. Attached to the follicle is a sebaceous gland, a tiny sebum-producing gland found everywhere except on the palms, lips and soles of the feet.
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In humans, there are four kinds of sudoriferous or sweat glands which differ greatly in both the composition of the sweat and its purpose.
  • eccrine glands - sweat (normal sweat used in temperature control)
  • apocrine glands - sweat,fats,proteins (slightly more viscous sweat)

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The sebaceous glands are glands found in the skin of mammals.

Locations and morphology

A branched type of acinar gland, these glands exist in humans throughout the skin except in the palms of the hands and soles of the feet.
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Apocrine sweat glands develop during the early to mid puberty ages approximately around the age of 13-15 and release more than normal amounts of sweat for approximately a month and subsequently regulate and release normal amounts of sweat after a certain period of time.
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The blood vessels are part of the cardiovascular system and function to transport blood throughout the body. The most important types, arteries and veins, carry blood away from or towards the heart, respectively.
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Areolar connective tissue (or loose connective tissue) is the most widely distributed connective tissue type in vertebrates.

Location

It can be found in the skin as well as in places that connect epithelium to other tissues.
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Friction is the force of two surfaces in contact. It is not a fundamental force, as it is derived from electromagnetic forces between atoms. When contacting surfaces move relative to each other, the friction between the two objects converts kinetic energy into thermal energy, or
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fingerprint is an impression of the friction ridges of all or any part of the finger.[1] A friction ridge is a raised portion of the epidermis on the palmar (palm and fingers) or plantar (sole and toes) skin, consisting of one or more connected ridge units of friction
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Recognition of human individuals involves physical recognition, such as visual, auditory, or behavior recognition.

Recognition of acquaintances

From nearby, a human individual is mainly recognized by his or her face; individuals with prosopagnosia
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Collagen is the main protein of connective tissue in animals and the most abundant protein in mammals, [1] making up about 25% of the total protein content.

Uses


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Elastic fibers (or yellow fibers) are bundles of proteins (elastin) found in connective tissue and produced by fibroblasts and smooth muscle cells in arteries. These fibers can stretch up to 1.5 times their length, and snap back to their original length when relaxed.
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Reticular fibers or reticulin is a histological term used to describe a type of structural fiber composed of type III collagen. Reticular fibers crosslink to form a fine meshwork (reticulum).
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Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
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The root of the hair ends in an enlargement, the hair bulb, which is whiter in color and softer in texture than the shaft, and is lodged in a follicular involution of the epidermis called the hair follicle.
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The sebaceous glands are glands found in the skin of mammals.

Locations and morphology

A branched type of acinar gland, these glands exist in humans throughout the skin except in the palms of the hands and soles of the feet.
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In humans, there are four kinds of sudoriferous or sweat glands which differ greatly in both the composition of the sweat and its purpose.
  • eccrine glands - sweat (normal sweat used in temperature control)
  • apocrine glands - sweat,fats,proteins (slightly more viscous sweat)

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nail is a horn-like structure at the end of a human's or an animal's finger or toe. See also claw.

Parts of the nail

Anatomically fingernails and toenails
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The blood vessels are part of the cardiovascular system and function to transport blood throughout the body. The most important types, arteries and veins, carry blood away from or towards the heart, respectively.
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A tattoo, or dermal pigmentation, is a mark made by inserting pigment into the skin for decorative or other reasons. Tattoos on humans are a type of decorative body modification, while tattoos on animals are most commonly used for identification or branding.
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Striae atrophicae
Classification & external resources

Stretch marks near the Navel
ICD-10 L 90.6
ICD-9 701.3

DiseasesDB 30027
MedlinePlus 003287
eMedicine derm/406   Stretch marks or striae
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Boston University (BU) is a private research university located in Boston, Massachusetts, United States. Although chartered by the Massachusetts Legislature in 1869, Boston University traces its roots to the establishment of the Newbury Biblical Institute in Newbury,
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In zootomy, the integumentary system is the external covering of the body, comprising the skin, hair, feathers, scales, nails, sweat glands and their products (sweat and mucus).
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Skin layers: epidermis, dermis, and subcutis, showing a hair follicle, sweat gland & sebaceous gland.]] In zootomy and dermatology, skin is the largest organ of the integumentary system made up of multiple layers of epithelial tissues that guard underlying muscles and organs.
..... Click the link for more information.
Perspiration (also called sweating or sometimes transpiration) is the production and evaporation of a fluid, consisting primarily of water as well as a smaller amount of sodium chloride (the main constituent of "table salt"), that is excreted by the sweat glands in the skin of
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