Corneous

Corneous Tissue

Corneous tissue, also known as keratinized tissue, is a type of epithelial tissue that is characterized by the presence of keratin, a fibrous structural protein. This tissue is primarily found in the outermost layer of the skin, known as the epidermis, as well as in other structures such as hair and nails.

Structure and Composition

Corneous tissue is composed of several layers of cells, with the outermost layer being the stratum corneum. This layer consists of dead, flattened keratinocytes that have lost their nuclei and are filled with keratin. The keratin provides a tough, protective barrier that is resistant to physical and chemical damage.

Keratinocytes

Keratinocytes are the predominant cell type in the epidermis, making up about 90% of the cells. These cells originate in the stratum basale, the deepest layer of the epidermis, and gradually move upwards as they differentiate and accumulate keratin.

Keratin

Keratin is a key structural protein that is insoluble in water, making it ideal for providing a waterproof barrier. It is also responsible for the mechanical strength of corneous tissue. There are two main types of keratin: alpha-keratin, found in humans and other mammals, and beta-keratin, found in reptiles and birds.

Functions

Corneous tissue serves several important functions in the human body:

• Protection: It acts as a barrier against environmental damage, pathogens, and dehydration.
• Regulation: It helps in regulating body temperature through the process of sweating and evaporation.
• Sensation: The skin contains sensory receptors that allow for the perception of touch, temperature, and pain.

Clinical Significance

Disorders of corneous tissue can lead to various skin conditions. Some common disorders include:

• Psoriasis: A condition characterized by the rapid turnover of keratinocytes, leading to thick, scaly patches on the skin.
• Ichthyosis: A group of genetic disorders that result in dry, scaly skin due to abnormal keratinization.
• Eczema: An inflammatory condition that can cause the skin to become red, itchy, and cracked.

Related Pages

• Epidermis
• Keratin
• Stratum corneum
• Keratinocyte
• Skin

Corneous

• 
  Horn
• 
  Viviparus contectus with operculum