Question

What is epidermis?

Answer 1

Hint: The epidermis is made up of cells that are flat in shape, called squamous cells and the layer provides a waterproof barrier to the body. It has one more function i.e it protects the body from infection by various pathogens.

Complete answer:
The epidermis is the outer layer of the skin.
The epidermis consists mainly of two layers, first one is the basal layer that is living, that is found next to the dermis layer, while the second layer is the stratum corneum that is located externally and is made up of dead, keratin-filled cells. The Basal cells are present under the squamous cells.

Additional Information: The epidermis consists of 4 or 5 layers, counting on the region of skin being considered.-The epidermis has no blood supply and it depends on the diffusion from the dermal cells for all its metabolic needs.
The dead-cell layer of the corneum protects from a water loss that permits the vertebrates to linger over land.
- Keratin, produced in migrating epidermal cells, forms the idea of nails in our fingers, feathers, and beaks of birds and other epidermal derivatives.
-The epidermis is thickest on the surfaces where friction will occur and thinnest over the eyelids, on the lower parts of the abdomen, and around the external genitalia.
-The epidermis consists of a living stratum germinativum, in touch with the basement membrane (which is attached to the dermis), and a superficial stratum corneum of dead cells. The stratum germinativum consists of both the stratum germinativum and therefore the stratum spinosum of the epidermis layer.

Note: It has been observed that the epidermis is composed of a malpighian layer that is living in nature, and is found in contact with the basement membrane (which in turn is attached to the dermis), and a superficial layer of horned-shape dead cells. This malpighian layer is composed of both layers of the epidermis that include the stratum spinosum and the stratum basale.