Dermis | Definition, Anatomy and Function


Dermis Definition

The dermis is the second layer of skin which present underneath the Epidermis and overhead the Subcutaneous layer. It is the most impenetrable layer of the skin, and generally, it is composed of elastic and fibrous tissue. In short, it delivers strength and elasticity to the skin.

Dermis Layers

The dermal layer is generally composed of two layers of cells:

  1. Papillary Dermis
  2. Reticular Dermis.


Papillary Dermis

The Papillary Dermis is a supplementary superficial layer which presents beneath the Epidermal intersection. It is comparatively thin. It is composed of Loose Connective Tissues.

Dermal Papillae

Papillae Dermal layer comprised of the following components:

  • Capillaries
  • �Elastic fibers
  • �Reticular fibers
  • �Collagen

Reticular Dermis

The reticular dermal layer is the subterranean and impenetrable Dermal layer, that is present overhead the Subcutaneous skin. Reticular Dermis comprised of the following components:

  • Blood vessels
  • Elastic fibers (interlaced)
  • Collagen fibers (in parallel layers)
  • Fibroblasts
  • Mast cells
  • Nerve endings
  • Lymphatics

Dermis cells

Fibroblasts are the chief cells and are accountable for the Procollagen and elastic fibers production. �After the enzymatic catalyzation, Procollagen is then converted into collagen. Approximately 70% of the weight of the dermal layer is comprised of Collagen.

Supplementary cells which are present in it consist of:

  • Mast cells: that comprised of granules of Histamine.
  • Vascular smooth muscle cells: present and accountable for relaxation or contraction of the blood vessels to preserve homeostasis of the temperature of the body.


Dermis Function

  • The principal role is to provide strength to the Epidermis and allow the skin to flourish.
  • It also plays a number of vitals roles due to the existence of hair follicles, sweat glands, sebaceous glands, nerve endings, and blood vessels.
  • Inside Dermal layers, Nerve endings are present which allows perceiving temperature, touch, pressure, and pain stimuli.
  • Sweat glands that are present inside the dermal layer that is accountable for the formation of sweat in answer to various conditions, like stress and heat.
  • When sweat evaporates over the skin, it can aid in cooling the body down to sustain homeostasis of the body.
  • When bacteria are present on the skin Apocrine sweat glands that are a special type of sweat glands located inside the armpits and near the genital organs are and they yield a dense, greasy sweat that generates the special distinctive body odor.
  • Sebaceous glands also present inside the dermal layer which is responsible for sebum exudation of sebum. Sebum is the oily material that aids to keep the skin soggy and helps to avert the entry of foreign substances like microbes.
  • Hair follicles are present in the dermal layer of skin which is responsible for hair production around the body.
  • Inside this layer of skin blood vessels are present which carry nutrients to the skin and remove waste products formed by metabolism inside the epidermis and dermal layer.