In: Anatomy and Physiology
Describe the tissue types and structure of the epidermis and dermis in detail?
Tissue types and structure of the epidermis and dermis
A group of similar cells that carry out a specific function is calle a tissue. There are four main types of tissues: Epithelial tissue, connective tissue, muscle and nervous tissue.
Epidermis and dermis are layers of the skin.
EPIDERMIS is a type of epithelial tissue, which line the outer surfaces of organs and blood vessel and the inner surfaces of internal organs. Epidermis made of keratinized stratified squamous epithelial tissue. The epidermis has five layers: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.
Stratum corneum - outermost layer of the skin consisting of keratinized cells.
Stratum lucidum - layer of dead cells in the epidermis beneath the corneum which appear translucent under a microscope
Stratum granulosum - thin layer of cells in the epidermis consisting of keratinocytes migrating from the stratum spinosum.
Stratum spinosum - is 2 to 4 cells thick and allow keratinocytes to mature
Stratum basale - deepest layer of epidermis composed of single layer of columnar or cuboidal cells.
DERMIS is a type of connective tissue and is located between the epidermis and subcutaneous tissue. It is composed of collagen, elastin and other extracellular components and it contains blood capillaries, nerve endings, sweat glands, hair follicles, and other structures.