What layer of the epidermis is actively mitotic?
The stratum basale or stratum germinativum undergoes constant mitosis to replace the cells exfoliated from the skin’s surface.
Which cells of the epidermis are mitotic?
All keratinocytes are formed by mitosis (cell division) in the lower region of the malpighian layer. Most of the dividing cells are found in the basal layer, although it is likely that about one-third of the divisions occur above this level.
Which epidermal stratum has the highest mitotic activity?
stratum basale layer
Mitotic activity in the epidermis is highest in the stratum basale layer.
Which layer of the skin do you find actively dividing epidermal cells?
The Basal Cell Layer The basal layer is the innermost layer of the epidermis, and contains small round cells called basal cells. The basal cells continually divide, and new cells constantly push older ones up toward the surface of the skin, where they are eventually shed.
What are the dermal papillae?
The dermal papillae (DP) (singular papilla, diminutive of Latin papula, ‘pimple’) are small, nipple-like extensions (or interdigitations) of the dermis into the epidermis. At the surface of the skin in hands and feet, they appear as epidermal, papillary or friction ridges (colloquially known as fingerprints).
Which of the following layers of the epidermis is made up of stem cells and so is in a constant state of replacement?
What are the characteristics of the stratum basale? Layer just one cell thick that joins the basal lamina of the epidermis to the upper surface of the dermis. The cells in this stratum are stem cells and so are in a constant state of mitosis, replacing cells that have rubber off the epidermis surface.
What are dermal papillae?
Which epidermal layer contains melanocytes and Merkel cells?
stratum basale
Stratum Spinosum and Granulosum Layers of the epidermis: The epidermis is made up of 95% keratinocytes but also contains melanocytes, Langerhans cells, Merkel cells, and inflammatory cells. The stratum basale is primarily made up of basal keratinocyte cells, which can be considered the stem cells of the epidermis.
What is the active layer of the epidermis above the papillary layer of the dermis?
Also known as basal cell layer; active layer of the epidermis above the papillary layer of the dermis; cell mitosis takes place here that produces new epidermal skin cells and is responsible for growth.
What type of epithelium is found in the epidermis?
stratified squamous epithelium
The epidermis is a cornified stratified squamous epithelium. It consists mainly of keratinocytes which multiply in the basal layer of the epithelium, and then leave this layer toward the outer surface. Along the way they undergo the process of keratinization before its dead.
Where is stratum granulosum found?
the epidermis
The stratum granulosum (or granular layer) is a thin layer of cells in the epidermis lying above the stratum spinosum and below the stratum corneum (stratum lucidum on the soles and palms). Keratinocytes migrating from the underlying stratum spinosum become known as granular cells in this layer.
What is an example of skin appendage?
The skin appendages include sweat glands, nails, and the pilosebaceous unit of the skin, comprised of the hair shaft, hair follicle, sebaceous gland, and arrector pili muscle — these appendages derive from a down growth of the epidermis beginning in the third month of fetal life.