Final answer:
The outermost layer of the skin is called the epidermis. It serves as a protective barrier and is composed of keratin-filled cells. Below the epidermis is the thicker dermis, followed by the hypodermis which contains fat and blood vessels.
Step-by-step explanation:
The epidermis is the outermost layer of the skin. It is a relatively thin layer composed of keratin-filled cells and serves as a barrier to water and pathogens. Below the epidermis is the much thicker dermis, which contains blood vessels, sweat glands, hair follicles, and sebaceous glands. The hypodermis, also known as the subcutaneous tissue, is the layer below the dermis that contains fat, blood vessels, and sensory neurons.