압구정피부과 The Dermis is a thick layer of connective tissue. It provides the skin with its strength and toughness. It contains blood vessels and nerves as well as epidermal invaginations such as hair follicles and sweat glands.
The vascular network in this layer supplies the epidermis with nutrients and removes waste. It also contributes to the pink tint of our skin and is responsible for giving us goosebumps.
The Papillary Layer
The thin layer of connective tissue directly beneath the epidermis is called the papillary dermis. This is the layer that gives elasticity to our skin. It contains blood vessels that supply the epidermis with nutrients and help regulate body temperature. It also contains hair follicles, sebaceous glands (oil glands), lymphatic vessels and sensory nerves.
The loose network of cells in this layer form finger-like projections, called dermal papillae, that extend into the epidermis. These papillae contain terminal networks of blood capillaries and tactile receptors called Meissner corpuscles. The blood vessels in this layer contract and expand to increase or decrease blood flow to the skin, thereby changing its temperature. This is one of the functions that helps cause blushing. The dermis also provides a pink tint to the skin and removes cell waste that would otherwise kill the cells.
The dermis is characterized by a network of coarse collagen fibers arranged irregularly and a few elastic fibers. These elastic fibers provide the stretch-recoil properties of our skin. This layer also contains fibroblasts, which produce collagen and other proteins that give our skin its strength and elasticity. It also contains fat cells (adipocytes), melanocytes, vascular and lymphatic vessels and hair follicles. In the stratum spinosum, which forms a layer just above this papillary layer, cells have a spiny appearance due to protruding cell processes that join them to each other via structures known as desmosomes.
The Reticular Layer압구정피부과
Underneath the papillary layer is the reticular layer, which is thicker and more dense. It has a net-like appearance, with lots of coarse, irregular collagen fibers. These provide structure and elasticity. This layer is well vascularized, with a rich supply of nerves that extend to the epidermis.
The dermis contains sweat glands, sebaceous glands, and hair follicles. It also contains blood vessels and a variety of cells, including fibroblasts and macrophages. These fibroblasts and macrophages help the skin heal after an injury, and make sure that nutrients get to the epidermis.
Another function of the dermis is to regulate body temperature. When your body’s temperature rises, the hypothalamus sends a message through the skin to the sweat glands, which in turn causes them to secrete sweat. This sweat cools the body. It also carries away heat, as it evaporates into the air.
The dermis contains sensory touch receptors, called Meissner’s corpuscles. These are found in the papillae in the papillary layer of the dermis, which protrude up into the epidermis. They can cause the ridges that we know as fingerprints. The papillae also contain capillary loops, and so they can receive and transmit pain signals. They can also sense vibration and pressure. The papillae in this layer also help to give the skin its distinctive pink tint by releasing a pigment called erythropoietin.
The Subcutis
The subcutis, which resides between the dermis layer and the fascia layer, is a network of fat lobules separated by connective tissue septa. It stores energy, protects deeper structures from shock, insulates and helps to regulate body temperature.
It is also the most vascular region of your skin. Blood vessels, lymphatic vessels, hair follicles, sebaceous glands and sweat glands are housed within this layer. Melanocytes, the cells that produce your skin color, are found in this layer as well. Nerves that sense touch, heat and pain are located here as well.
As you age, the thickness of your subcutis decreases and this is what causes your skin to sag. If the hypodermis layer becomes thin enough, the fascia layers and underlying muscles will be exposed, which is why it is important to keep this layer intact with regular exercise, a healthy diet and a good moisturizer.
Also known as adipose tissue, your subcutaneous fat consists of clusters or sheets of lipid-filled cells called adipocytes. Your adipose tissue contains 9-18% and 14-20% of the normal body weight for men and women respectively. It acts as a cushion and absorbs the shock of blunt trauma. It also serves as a reserve source of energy for your body and helps to regulate the temperature of the body. The adipose tissue in the subcutis of your skin also contributes to the elasticity and resilience of your skin.
The Nervous Layer
Your skin has a large network of blood vessels in your dermis. These help regulate your temperature, deliver nutrient supplies and remove the cellular waste products that would otherwise kill the epidermal cells. Your dermis also contains nerve endings, which send signals to your brain that let you feel different sensations, such as pressure, heat and cold.
The reticular layer of your dermis is thick and densely packed with a collagen-rich matrix. It merges with the inferior surface of your papillary layer and has a spiny appearance due to protruding cell structures called desmosomes, which interlock to strengthen the bond between the cells.
Its function is to support the epidermis and provide a cushion that protects your muscles, organs and tissues from injury. Your dermis also has hair follicles, sweat glands, sebaceous glands (oil glands) and lymphatic vessels.
The stratum granulosum forms the outermost layer of your epidermis. It has a grainy appearance due to further changes in the keratinocytes that make up this layer. The keratinocytes become flatter and more crowded together as they make the proteins keratin and keratohyalin. These proteins give hair, nails and your skin their hardness and water resistance. Your body’s natural oils, which keep your skin hydrated, are secreted by the sebaceous glands in this layer. Your skin also has receptors in this layer that detect gentle pressure, vibration and heat.