Collagen and elastin are two proteins that help skin to maintain its strength, elasticity and structure. Collagen makes up approximately 75% of the skin’s dry weight, while elastin comprises about 15%. They are responsible for the strength and support of the skin, and their degradation is a key factor in sagging, wrinkling and the appearance of aging skin.
The epidermis (the outermost layer of skin) naturally loses collagen and elastin as we age. In addition, smoking and sun exposure can damage these proteins, causing them to break down at an increased rate. As a result, collagen and elastin levels will continue to drop as we age.
When collagen and elastin levels decrease in the skin, it becomes more fragile and begins to lose its ability to bounce back into shape after being stretched. The connective tissue supporting the blood vessels in our skin is also weakened, leading to spider veins on the legs or broken capillaries on the face.
Elastin and collagen are the two major proteins of the dermis. The dermis is the underlying layer of skin that supports the epidermis and gives it strength. Elastin is a very elastic protein which allows tissues to recoil after stretching. Collagen, on the other hand, is a very tough protein that gives structure to tissues.
In young skin over 80% of the dermal proteins are collagen and elastin. In mature skin this percentage decreases to 65%. This decrease in collagen leads to loose skin and wrinkles. Elastin forms an organized network of fibers that resemble a rubber band. In addition, elastin helps wounds heal by allowing new cells to stretch into position.
Mutated genes cause diseases that affect collagen or elastin or both. Some of these diseases have symptoms that affect only the skin, while others also affect other parts of the body.
The skin is the largest organ of the body, accounting for approximately 15% of the total body weight. It covers an area of approximately 20 square feet. The skin has three layers: the epidermis, or outer layer; the dermis, or middle layer; and the subcutaneous tissue, or deepest layer. The epidermis is made up of three distinct layers: the stratum corneum, stratum lucidum (only present in thick skin such as that on the palms and soles), and stratum granulosum. Below these layers lies the stratum spinosum, a layer containing several cell types including keratinocytes and Langerhans cells. These cells are attached to each other by desmosomes. The stratum basale is found at the base of the epidermis and is attached to the dermis through a basement membrane. The epidermis is responsible for providing a barrier to protect underlying tissues from infection, dehydration, chemicals and mechanical stress.
Collagen and elastin are two major structural components of mammalian connective tissues that allow for motion without tearing or deformation. Collagen is a triple helical molecule composed of three structurally similar polypeptide chains coiled together. Elastin is
Collagen and elastin are the two most important proteins that make up the dermis. Collagen is the scaffolding that gives strength and structure, while elastin is the resilient fiber that maintains skin’s ability to stretch. When collagen and elastin fibers break down, skin loses its strength and elasticity. Wrinkles form, and skin sags. Damage to collagen and elastin fibers results in a loss of firmness, leading to wrinkles and sagging skin.
The epidermis is the outermost layer of our skin. It provides a waterproof barrier and creates our skin tone. The epidermis is mostly made of flat, scale-like cells called squamous cells. Underneath the squamous cells are round cells called basal cells. The deepest part of this layer contains melanocytes. These are pigment-containing cells that give our skin its natural color.
The epidermis can be further divided into the following layers (beginning with the outermost layer):
The epidermis covers the body in a protective layer of epithelial cells that form the outermost layer of skin. It is composed of multiple layers of flattened cells that overlie a base layer (stratum basale) composed of columnar cells arranged perpendicularly. The layers of the epidermis include the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale.
In response to damaging stimuli, cells in the stratum basale proliferate and move up through the other layers until they reach the top. Here they are shed as part of desquamation, the process by which dead superficial cells are continually shed.
New cells are made within the stratum basale by mitosis and move up through the other layers before being shed. Thus, mature human epidermis is composed primarily of dead cells.
The thickness varies throughout on different parts of the body from 0.5 mm on eyelids to 1.5 mm on palms and soles. In humans there are only four to five strata instead of seven as in many other mammals.
The epidermis is the outermost layer of the skin. It forms a protective barrier over the body’s surface, responsible for keeping water in the body and preventing pathogens from entering, and is a stratified squamous epithelium, composed of proliferating basal and differentiated suprabasal keratinocytes. Keratinocytes are the major cells, constituting 95% of the epidermis, while Merkel cells and Langerhans cells are present; the latter reside in the deepest level of the epidermis and are part of the immune system. The epidermis can be further subdivided into the following strata (beginning with the outermost layer): corneum, lucidum (only in palms of hands and soles of feet), granulosum, spinosum, basale. Cells are formed through mitosis at the basale layer. The daughter cells move up the strata changing shape and composition as they undergo multiple stages of cell differentiation to eventually become anucleated corneocytes (corneous cells). Corneocytes contain a protein envelope underneath the plasma membrane, attached to filamentous proteins embedded in a glycocalyx matrix. The corneocytes are then connected through corneodesmosomes to create cohesive layers.
The epidermis is the outermost layer of the skin. Its main function is to serve as a barrier against environmental insults, including ultraviolet (UV) radiation and mechanical, chemical, or thermal trauma. It is composed of four or five layers of cells that are continually shed from the surface and replaced by new cells originating from deeper layers. The epidermis itself does not contain blood vessels and derives all of its nutrients from underlying tissues. The epidermis is generally classified into five layers: basale, spinosum, granulosum, lucidum, and corneum. The inner three layers are responsible for cell replication and keratinization (the process of making keratin). The outermost layer is made up of dead cells that have been flattened underneath newer living epidermal cells. These dead cells are continuously shed off the skin surface (desquamation), which causes the body to lose about 50 million skin cells every day!
The epidermis is different in thickness depending on its location on the body. Skin found on areas like the palms or soles may be 15 cell layers thick as compared to 1-2 cell layers thick in areas such as eyelids or genitals. This difference in thickness is due to specific environments that certain areas of the body