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The papilla is a large structure at the base of the hair follicle. [4] The papilla is made up mainly of connective tissue and a capillary loop. Cell division in the papilla is either rare or non-existent. [contradictory] Around the papilla is the hair matrix. A root sheath composed of an external and
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 ...
The dermis has two layers: the papillary dermis and the reticular layer. The papillary layer is the superficial layer that forms finger-like projections into the epidermis (dermal papillae), [5] and consists of highly vascularized, loose connective tissue. The reticular layer is the deep layer of the dermis and consists of the dense irregular ...
The longer the hair stays in the anagen phase, the longer it will grow. During this phase, cells neighboring the papilla in a germinative layer divide to produce new hair fibers, [13] and the follicle buries itself into the dermal layer of the skin to nourish the strand. About 85%–90% of the hairs on one's head are in the anagen phase at any ...
The human skin is the outer covering of the body and is the largest organ of the integumentary system. The skin has up to seven layers of ectodermal tissue guarding muscles, bones, ligaments and internal organs. Human skin is similar to most of the other mammals ' skin, and it is very similar to pig skin. Though nearly all human skin is covered ...
Each arrector pili is composed of a bundle of smooth muscle fibres which attach to several follicles (a follicular unit). [4] Each is innervated by the sympathetic division of the autonomic nervous system. [4] The muscle attaches to the follicular stem cell niche in the follicular bulge, [3] [4] [5] splitting at their deep end to encircle the ...
The base of the hair follicle contains the bulb, housing dermal fibroblasts known as the dermal papilla, crucial for morphogenesis and the hair follicle's cyclic activity. Encircling these cells is the matrix cell region, the hair follicle's proliferative compartment, responsible for the formation of different follicle compartments (except the ...
the hair shaft, which is the hard filamentous part that extends above the skin surface. It is made of multi-layered keratinized (dead) flat cells whose rope-like filaments provide structure and strength to it. The protein called keratin makes up most of its volume. A cross section of the hair shaft may be divided roughly into three zones.