What is the outer, thinner layer of the skin composed of living and dead skin cells?

• A. Dermis
• B. Epidermis
• C. Hypodermis
• D. Subcutaneous layer

Answer: (B)

The outer, thinner layer of the skin is the epidermis. It is made of keratinized stratified squamous epithelium, with living cells in the deeper parts that divide and move outward, where they accumulate keratin and eventually die. This gives the surface its dead, flattened cells and creates a tough, protective barrier that helps prevent water loss. The epidermis has no blood vessels, so it relies on the underlying dermis for nutrients. Beneath that, the dermis is thicker and contains connective tissue, blood vessels, nerves, and glands, while the hypodermis (subcutaneous layer) lies underneath and consists mainly of fat.