Histology of the skin - Term Paper Example

Histology of the Skin The skin among the most vital organs found on the human body. This is so because it is the body’s first structure of defense against diseases. A healthy skin has certain characteristics; it is soft, moist, and flexible with a smooth fine texture. A healthy skin also is naturally acidic, a factor that protects it against microorganisms that may try to enter it. This paper will explore the histology of the skin.The skin is one of the largest organs in the body and varies in thickness.

It is thickest on the soles of the feet and palm of the hand. It is, however, thinnest on the eyelids and on the face. Continued pressure on the skin may cause it to thicken. The appendages of the skin include the nails, hair, sweat gland, and oil glands (Milady 220).The skin is grouped into two main divisions namely the epidermis and the dermis. The epidermis also known as cuticle is the outermost layer of the skin. Its main purpose is to offer protection to the body. It is the thinnest layer and contains no blood vessels but has numerous small nerve endings.

The layer is divided into five sub-layers namely the stratum corneum, stratum lucidum, stratum granulosum, and stratum spinosum and stratum germinativum (Milady 220). Stratum corneum or horny layer is the outermost layer of the epidermis. It is composed of packed scale-like cells, which are usually shed off and replaced by other new cells coming to the surface from the layers beneath it. The cells are made up of chemical proteins known as Keratin, which mixes with sebum, a thin layer of oil, to aid in protecting and waterproofing the horny layer (Milady 220).

The stratum lucidum also known as clear layer lies underneath the horny layer. It consists of small transparent cells through which rays from the sun pass. The stratum granulosum or granular layer consists of a group of cells that resembles granules. The cells are usually dead and are normally pushed to the surface to substitute the cells that have been shed from the stratum corneum (Busam, and Goldblum 2). The stratum spinosum or spiny layer is a sub-layer and usually lies above the basal stratum and beneath stratum granulosum.

Milady (220) notes that it is in the stratum spinosum that the process that causes skin cells to shed starts. The stratum germinativum, malpighian, or basal cell layer is part of the epidermis found deepest. It consists of a dark pigment known as melanin that protects the skin from ultraviolet rays of the sun. It is also responsible for development of the epidermis (Milady 220).Dermis also known as derma, corium, true skin, or cutis is the inner layer of the skin. It is about 25 thicker than the epidermis.

It consists of sensitive vascular layer of connective tissues. It has numerous blood vessels, oil glands, nerves, lymph nodes, hair follicles papillae and erector pili muscles. The dermis is composed of two layers namely the papillary or superficial layer and the reticular or the deeper layer (Busam, and Goldblum 2). The papillary layer lies immediately beneath the stratum germinativum of the epidermis. The papillary layer is made up of small con-shaped projections of tissues known as papillae that usually points upwards into the epidermis.

Some papillae have blood vessels while others contain tactile corpuscles with nerve fiber endings, which are sensitive to touch and pressure. The layer also has some melanin that protects it from ultraviolet rays of the sun (Busam, and Goldblum 3). The reticular layer of the dermis is the deeper layer, which supplies the skin with nutrients and oxygen. The layer consists of the following; fat cells, oil glands, sweat glands, lymph glands, blood vessels, hair follicles, and erector pili muscles.

The dermis also has the adipose tissue or the subcutaneous tissue which is a layer of fatty tissues located below the dermis. Adipose tissue varies in thickness usually according to age, health, and gender. It is responsible for giving the body smoothness and contour. It contains fats that the body uses as a source of energy and for protection of the outer skin (Milady 222).The skin is composed of different nerve fibers that perform different functions. It has the motor nerve fiber that triggers goose bumps during change in weather or when one is frightened.

Sensory nerve fibers acts as receptors that send messages to the brain usually those of touch, heat, pressure, cold, pain and cold. Secretory nerves fibers help in regulating the excretion of sweat from the sweat glands (Busam, and Goldblum 3). The skin as a body organ performs other vital functions in the body such as heat regulation, absorption, protection against injury and organisms, excretion of sweat, secretion that keeps the body smooth and soft. It also acts as a sensory organ (Milady 222).

Work CitedBusam, Klaus & Goldblum, John. Dermatopathology E-Book: A Volume in the Foundations. New York: Elsevier Health Sciences. 2009. Print.Milady, Maura. Miladys Standard Professional Barbering. Fifth Edition, New York: Cengage Learning. 2010. Print.