Question

List the similarities and differences of the layers of the epidermis.

Answer 1

Epidermis is the superficial layer of skin composed of five strata.

listed from deep to superficial are:

1)Stratum Basale

2)Stratum spinosum

3)Stratum Granulosum

4)Stratum corneum

The fifth most layer of epidermis is called Stratum Lucidum.Located in the palms and soles which is thick.and the remaining four strata are thin.

Function: Prevents water loss and the entry of chemicals and microorganisms
Protects against abrasion and ultraviolet light
produces vitamin D.
Gives rise to hair, nails, and glands

Similarities:

• One similarity between all the epidermis layers, except stratum Basale,is that all the cells in these layers are called Keratinocytes  These cells produce and storage the protein Keratin, which is an intracellular fibrous protein that gives skin, nails and hair its strength.
• All the layers are made of epithelial cells and are tightly packed.
• There are no blood vessels found in any of the layers, which means they are avascular.

Differences:

• The inner most epidermal layer, called Stratum Basale, is made up on cuboidal cells. This is where new cells are produced and pushed towards the outside.
• Stratum spinosum contains Langerhans cells, and these cells help against harmful and foreign pathogens.
• Stratum Granulosum contains lamellar granules. The lamellar granules contain another type of protein called Keratinohyalin.
• Stratum Lucidum, which is found only in think skin, contains proteins that give the effect of being translucent.
• Stratum Corneum, the superficial most layer, is composed of hard, dead skin cells. These cells are constantly replaced by new cells that are made in Stratum Basale.