Definition of Papillary Layer

The skin of the human body is its most extensive organ system. It is the primary line of defense against disease causing bacteria. It provides protection for the underlying structures and even regulates temperature. It is composed of two layers, the epidermis and dermis. The papillary layer is a part of the dermis layer of skin.

Identification

The dermis is often called the "true skin." It is underneath the epidermis. It is composed of two layers: the papillary and the reticular. Throughout the whole dermis there are three types of tissue. These are collagen, elastic and reticular fibers. While these are contained in both layers of the dermis, the papillary layer primarily has collagen fibers.

Function

The papillary layer is located directly under the epidermis and is attached to it via papillae. Papillae are projections that are finger-like in appearance. The papillae serve some important functions. One is to nourish the epidermis. Therefore, some of them contain capillaries. Another job for the papillae is to provide the touch sensation. Those that serve this purpose contain Meissner's corpuscles, which are sensory touch receptors.

Function

An interesting function for the papillae is the creation of fingerprints and footprints. These are created due to double rows of papillae. Fingerprints and footprints are useful in assisting in gripping objects and in preventing the skin from tearing.

Size

The dermis varies in thickness. For example, the eyelids are about 0.3 mm while the back is usually about 3 mm. The papillary layer of the dermis is the thinner part, as it contains thinner fibers than the reticular layer.

Types

There are various types of cells and structures that are throughout the dermis, including the papillary layer. Some of these include hair follicles, erector pili muscles (they attach the hair follicle to the layer), blood vessels, nerve cells (convey pain and temperature information), and sweat glands.

Effects

The skin is so complex and amazing in its efficiency as an organ system. The papillary layer is definitely an example of this. It appears to almost be the "middleman" in the functioning between the epidermis and dermis. It is so connected to the reticular layer that it is often difficult to differentiate where one ends and the other begins. It is a hard working team player in the skin's functioning.