Dermis

From Wikipedia, the free encyclopedia

Jump to navigation
Jump to search

Dermis
Skin.png

Cross-section of human skin
Normal Epidermis and Dermis with Intradermal Nevus 10x.JPG

Cross section of skin under the microscope
Details
Part of Skin
Identifiers
MeSH D020405
TA A16.0.00.010
TH H3.12.00.1.03001
FMA 70323
Anatomical terminology

[ edit on Wikidata ]

The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis ) and subcutaneous tissues , that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided into two layers, the superficial area adjacent to the epidermis called the papillary region and a deep thicker area known as the reticular dermis. [1] The dermis is tightly connected to the epidermis through a basement membrane . Structural components of the dermis are collagen , elastic fibers , and extrafibrillar matrix . [2] It also contains mechanoreceptors that provide the sense of touch and thermoreceptors that provide the sense of heat . In addition, hair follicles , sweat glands , sebaceous glands , apocrine glands , lymphatic vessels and blood vessels are present in the dermis. Those blood vessels provide nourishment and waste removal for both dermal and epidermal cells.

Contents

  • 1 Structure
  • 2 Layers
    • 2.1 Papillary dermis
    • 2.2 Reticular dermis
    • 2.3 Dermal papillae
  • 3 See also
  • 4 References

Structure[ edit ]

The dermis is composed of three major types of cells : [3] fibroblasts , macrophages , and adipocytes .

Apart from these cells, the dermis is also composed of matrix components such as collagen (which provides strength ), elastin (which provides elasticity ), and extrafibrillar matrix , an extracellular gel-like substance primarily composed of glycosaminoglycans (most notably hyaluronan ), proteoglycans , and glycoproteins . [3]

Layers[ edit ]

Illustration of dermal circulation and layers

Papillary dermis[ edit ]

The papillary dermis is the uppermost layer of the dermis. It intertwines with the rete ridges of the epidermis and is composed of fine and loosely arranged collagen fibers. [2]

The papillary region is composed of loose areolar connective tissue . This is named for its fingerlike projections called papillae, that extend toward the epidermis and contain either terminal networks of blood capillaries or tactile Meissner’s corpuscles . [4]

Reticular dermis[ edit ]

The reticular dermis is the lower layer of the dermis, found under the papillary dermis, composed of dense irregular connective tissue featuring densely packed collagen fibers. It is the primary location of dermal elastic fibers. [2]

The reticular region is usually much thicker than the overlying papillary dermis. It 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. Within the reticular region are the roots of the hair , sebaceous glands , sweat glands , receptors , nails , and blood vessels. The orientation of collagen fibers within the reticular dermis creates lines of tension called Langer’s lines , which are of some relevance in surgery and wound healing. [5]

Dermal papillae[ edit ]

Dermal papillae
Gray936.png

Papilla of the hand, treated with acetic acid. Magnified 350 times.

A. Side view of a papilla of the hand.
a. Cortical layer.
b. Tactile corpuscle.
c. Small nerve of the papilla, with neurolemma .
d. Its two nervous fibers running in spiral coils around the tactile corpuscle.
e. Apparent termination of one of these fibers.

B. Tactile papilla seen from above so as to show its transverse section.
a. Cortical layer.
b. Nerve fiber.
c. Outer layer of the tactile body, with nuclei.
d. Clear interior substance.

Details
Identifiers
Latin papillae dermis
MeSH D020405
TA A16.0.00.010
TH H3.12.00.1.03001
FMA 70323
Anatomical terminology

[ edit on Wikidata ]

The dermal papillae (DP) (singular papilla, diminutive of Latin papula, ‘pimple’) are small, nipple-like extensions (or interdigitations) of the dermis into the epidermis . At the surface of the skin in hands and feet, they appear as epidermal or papillary ridges (colloquially known as fingerprints ).

Blood vessels in the dermal papillae nourish all hair follicles and bring nutrients and oxygen to the lower layers of epidermal cells. The pattern of ridges they produce in hands and feet are partly genetically determined features that develop before birth. They remain substantially unaltered (except in size) throughout life, and therefore determine the patterns of fingerprints, making them useful in certain functions of personal identification.
[6]

The dermal papillae are part of the uppermost layer of the dermis, the papillary dermis , and the ridges they form greatly increase the surface area between the dermis and epidermis. Because the main function of the dermis is to support the epidermis, this greatly increases the exchange of oxygen, nutrients, and waste products between these two layers. Additionally, the increase in surface area prevents the dermal and epidermal layers from separating from each other by strengthening the junction between them. With age, the papillae tend to flatten and sometimes increase in number.
[7]

Dermal papillae also play a pivotal role in hair formation, growth and cycling.
[8]

In mucous membranes , the equivalent structures to dermal papillae are generally termed “connective tissue papillae”, which interdigitate with the rete pegs of the superficial epithelium.

See also[ edit ]

  • List of cutaneous conditions

References[ edit ]

  1. ^ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews’ Diseases of the Skin: Clinical Dermatology (10th ed.). Saunders. Pages 1, 11–12.

    ISBN   0-7216-2921-0 .

  2. ^ a b c Marks, James G; Miller, Jeffery (2006). Lookingbill and Marks’ Principles of Dermatology (4th ed.). Elsevier Inc. Page 8–9. ISBN   1-4160-3185-5 .
  3. ^ a b The Ageing Skin – Structure
  4. ^ http://microvet.arizona.edu/Courses/vsc422/secure/VSC422AppledHistologyLabHandout.pdf
  5. ^ Ross M, Pawlina W (2011). Histology: A Text and Atlas (6th ed.). Lippincott Williams & Wilkins. p. 498. ISBN   978-0-7817-7200-6 .
  6. ^ “Dermal papillae” . Probert Encyclopaedia. Retrieved February 2010. Check date values in: |accessdate= ( help )
  7. ^ “Friction Skin” . Ridges and Furrows. Retrieved February 2010. Check date values in: |accessdate= ( help )
  8. ^ Lin, Chang-min; et al. (October 2008). “Microencapsulated human hair dermal papilla cells: a substitute for dermal papilla?” . Archives of Dermatological Research. Springer. 300 (9): 531–535. doi : 10.1007/s00403-008-0852-3 .
  • v
  • t
  • e
Skin and related structures
Skin
Epidermis
  • Stratum corneum
  • Stratum lucidum
  • Stratum granulosum
  • Stratum spinosum
  • Stratum basale
Basement membrane
  • Basal keratinocyte
  • Lamina lucida
  • Lamina densa
Dermis
  • Papillary
    • Dermal papillae
  • Reticular
Subcutaneous tissue
  • Panniculus / Pannus ( Panniculus adiposus
  • Panniculus carnosus )
  • Membranous layer
  • Loose connective tissue
  • Superficial fascia
Adnexa
Skin glands
  • Sweat glands : Apocrine sweat gland
  • Eccrine sweat gland
  • Sebaceous
Hair
Root sheath
  • Outer root sheath
  • Inner root sheath
    • Henle’s layer
    • Huxley’s layer
Hair shaft
  • Cuticle
  • Cortex
  • Medulla
  • Bulb with matrix cells
  • Hair follicle
Muscle
  • Arrector pili muscle
Pilosebaceous unit
  • Hair sebaceous gland
Nail
  • Nail matrix
  • Nail plate
    • Lunula
  • Eponychium
  • Paronychium
  • Hyponychium
  • v
  • t
  • e
Connective tissues
Physiology
  • Soft tissue
  • Fibrosis
  • Scarring
Composition
Cells
Resident
  • Fibroblast
  • Fibrocyte
  • Reticular cell
  • Tendon cell
  • Adipocyte
  • Melanocyte
Wandering cells
  • Mast cell
  • Macrophage
Extracellular
matrix
Ground substance
  • Tissue fluid
Fibers
  • Collagen fibers
  • Reticular fibers
    • COL3A1
  • Elastic fibers
    • Elastin
    • Fibrillin
    • FBN1
      • FBN2
      • FBN3
    • EMILIN1
    • Elaunin
Types
Proper
Loose
  • Reticular
  • Adipose
    • Brown
    • White
Dense
  • Dense irregular connective tissue
    • Submucosa
    • Dermis
  • Dense regular connective tissue
    • Ligament
    • Tendon
    • Aponeurosis
Embryonic
  • Mucoid
  • Mesenchymal
Specialized
  • Cartilage
  • Bone
  • v
  • t
  • e
Routes of administration , dosage forms
Oral
Digestive
tract ( enteral )
Solids
  • Pill
  • Tablet
  • Capsule
  • Pastille
  • Time release technology
  • Osmotic delivery system (OROS)
FlattenedRoundPills.jpg
Hexaaquatitanium(III)-solution.jpg
Liquids
  • Decoction
  • Elixir
  • Electuary
  • Emulsion
  • Extended-release syrup
  • Effervescent powder or tablet
  • Herbal tea
  • Hydrogel
  • Molecular encapsulation
  • Powder
  • Softgel
  • Solution
  • Suspension
  • Syrup
  • Syrup Concentrate for dilution and/or addition of carbonated water
  • Tincture
Buccal ( sublabial ), sublingual
Solids
  • Orally disintegrating tablet (ODT)
  • Film
  • Lollipop
  • Sublingual drops
  • Lozenges
  • Effervescent buccal tablet
  • Chewing gum
Liquids
  • Mouthwash
  • Toothpaste
  • Ointment
  • Oral spray
Respiratory
tract
Solids
  • Smoking device
  • Dry-powder inhaler (DPI)
Inhaler.jpg
0
0
Liquids
  • Anaesthetic vaporizer
  • Vaporizer
  • Nebulizer
  • Metered-dose inhaler (MDI)
Gas
  • Oxygen mask and Nasal cannula
  • Oxygen concentrator
  • Anaesthetic machine
  • Relative analgesia machine
Ophthalmic ,
otologic , nasal
Action photo of nasal spray on a black background.jpg
  • Nasal spray
  • Ear drops
  • Eye drops
  • Ointment
  • Hydrogel
  • Nanosphere suspension
  • Insufflation
  • Mucoadhesive microdisc (microsphere tablet)
Urogenital
  • Ointment
  • Pessary (vaginal suppository)
  • Vaginal ring
  • Vaginal douche
  • Intrauterine device (IUD)
  • Extra-amniotic infusion
  • Intravesical infusion
  • Rectal ( enteral )
    Glycerin suppositories.jpg
    • Ointment
    • Suppository
    • Enema
      • Solution
      • Hydrogel
    • Murphy drip
    • Nutrient enema
    Dermal
    SPF15SunBlock.JPG
  • Ointment
  • Topical cream
  • Topical gel
  • Liniment
  • Paste
  • Film
  • DMSO drug solution
  • Electrophoretic dermal delivery system
  • Hydrogel
  • Liposomes
  • Transfersome vesicles
  • Cream
  • Lotion
  • Lip balm
  • Medicated shampoo
  • Dermal patch
  • Transdermal patch
  • Contact (rubbed into break in the skin)
  • Transdermal spray
  • Jet injector
  • Injection ,
    infusion
    (into tissue/blood)
    Skin
  • Intradermal
  • Subcutaneous
  • Transdermal implant
  • Injection Syringe 01.jpg
    Organs
    • Intracavernous
    • Intravitreal
    • Intra-articular injection
    • Transscleral
    Central nervous system
    • Intracerebral
    • Intrathecal
    • Epidural
    Circulatory , musculoskeletal
    • Intravenous
    • Intracardiac
    • Intramuscular
    • Intraosseous
    • Intraperitoneal
    • Nanocell injection
    • Patient-Controlled Analgesia pump
    • PIC line
    • Category Category
    • WikiProject WikiProject
    • Tabletten.JPG Pharmacy portal

    Retrieved from ” https://en.wikipedia.org/w/index.php?title=Dermis&oldid=865701858 ”
    Categories :

    • Skin anatomy
    • Routes of administration
    Hidden categories:

    • CS1 errors: dates