Papillary dermis

Papillary dermis is the uppermost layer of the dermis, which is a layer of the skin. It lies below the epidermis and above the reticular dermis. The papillary dermis is named for its finger-like projections called dermal papillae that extend towards the epidermis. These projections increase the surface area between the dermis and epidermis, allowing for increased exchange of oxygen, nutrients, and waste products.

The papillary dermis is composed of loose connective tissue and is rich in small blood vessels. It also contains lymphatic vessels, nerve endings, and touch receptors known as Meissner's corpuscles. The papillary dermis plays a crucial role in temperature regulation, sensation, and immune defense.

Structure

The papillary dermis is characterized by thin, collagenous fibers known as collagen type III. These fibers are loosely arranged, allowing for flexibility and movement. The papillary dermis also contains elastin fibers, which provide elasticity to the skin.

The dermal papillae that characterize the papillary dermis are not uniformly distributed. They are more numerous in areas of the skin that are exposed to friction, such as the palms of the hands and the soles of the feet. These areas also contain more Meissner's corpuscles, which are responsible for the sense of touch.

Function

The papillary dermis has several important functions. It provides nutrients and oxygen to the epidermis through its rich network of blood vessels. It also plays a role in temperature regulation by controlling the amount of blood flowing to the skin's surface. In addition, the papillary dermis is involved in the immune response, as it contains lymphatic vessels that carry white blood cells to and from the skin.

The nerve endings in the papillary dermis are responsible for the sensation of touch. The Meissner's corpuscles, in particular, are sensitive to light touch and vibrations.

Clinical significance

Changes in the papillary dermis can be indicative of certain skin conditions. For example, a thinning of the papillary dermis is often seen in aging skin and in skin affected by chronic sun damage. Inflammatory skin conditions, such as psoriasis and eczema, can also affect the papillary dermis.

Papillary dermis Resources
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