The papillary dermis is the very top layer of the skin, which serves to protect the body from the external environment. It contains blood vessels, which supply the skin tissue with essential nutrients and oxygen, as well as regulating body temperature. This layer of dermis also includes free nerve endings in sensitive parts of the body. The nerves help protect the body from danger, such as sharp objects and heat, and send messages to the brain and spinal cord to protect the body by regulating body temperature or avoiding a source of pain.
The most essential function of the papillary dermis is to protect the muscles and internal organs of the body. The skin is actually an external organ that is elastic and stretches over the entire body. It keeps germs and other harmful materials from coming into contact with the sensitive and vulnerable systems within the skin that keep humans and other animals alive.
The papillary dermis contains blood vessels that serve two primary functions. One of these functions is to provide the tissue of the skin with vital nutrients and oxygen. The blood vessels also remove used, oxygen-depleted blood from the skin to make room for fresh blood.
The second function of the blood vessels within the papillary dermis to to regulate body temperature. Nerves present in the skin tell the body what the surrounding temperature is. This information can be used to either conserve or dissipate heat by increasing or decreasing blood flow to the dermis.
Free nerve endings are also contained within the papillary dermis in highly sensitive areas of the body, such as the fingers and genitals. These nerves are directly connected to the brain and spinal cord through the periphery nervous system. The nerves are located in the top layer of the skin in order to best determine the surrounding environment. They can tell the body that it is too cold or too hot in the surrounding environment, which the central nervous system will use to conserve or disperse heat.
The nerves in the papillary dermis can also sense danger in the surrounding environment other than from temperature. These nerves are responsible for sending pain messages to the brain and connected nervous system. When pain is detected on the skin from trauma or some other source, the nerves send a reaction through the body that determines how the body reacts to the sensation. This can be experienced when the skin comes in contact with a sharp edge, and the nervous system responds by causing the person to flinch away from the source of the pain.