Dermal papillae
Encyclopedia
In the human skin
, the dermal papillae (DP) (singular papilla, diminutive of Latin papula, 'pimple') are small, nipple-like extensions (or interdigitations) of the dermis
into the epidermis. They can be observed at the surface of the skin in hands and feet as epidermal or papillary ridges (colloquially known as fingerprint
s).
The dermal papillae nourishes all hair follicle
s and bring food and oxygen to the lower layers of epidermal cells. The pattern of ridges they produce in hands and feet are inherited features that are developed before birth. They remain unaltered (except in size) throughout life, and are therefore used for fingerprints.
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 dermis' main function 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 prevent the dermal and epidermal layers from separating from each others by strengthening the junction between them. With age, the papillae tend to flatten and sometimes increase in numbers.
Dermal papillae also play a pivotal role in hair formation, growth and, cycling.
Skin
-Dermis:The dermis is the 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 Mechanoreceptors that provide the sense of touch and heat...
, the dermal papillae (DP) (singular papilla, diminutive of Latin papula, 'pimple') are small, nipple-like extensions (or interdigitations) of the dermis
Dermis
The dermis is a layer of skin between the epidermis and subcutaneous tissues, and is composed of two layers, the papillary and reticular dermis...
into the epidermis. They can be observed at the surface of the skin in hands and feet as epidermal or papillary ridges (colloquially known as fingerprint
Fingerprint
A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger. In a wider use of the term, fingerprints are the traces of an impression from the friction ridges of any part of a human hand. A print from the foot can also leave an impression of friction ridges...
s).
The dermal papillae nourishes all hair follicle
Hair follicle
A hair follicle is a skin organ that produces hair. Hair production occurs in phases, including a growth phase , and cessation phase , and a rest phase . Stem cells are principally responsible for the production of hair....
s and bring food and oxygen to the lower layers of epidermal cells. The pattern of ridges they produce in hands and feet are inherited features that are developed before birth. They remain unaltered (except in size) throughout life, and are therefore used for fingerprints.
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 dermis' main function 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 prevent the dermal and epidermal layers from separating from each others by strengthening the junction between them. With age, the papillae tend to flatten and sometimes increase in numbers.
Dermal papillae also play a pivotal role in hair formation, growth and, cycling.