Biological Systems MCAT Practice Exam 2025 – The Comprehensive All-in-One Guide for Exam Success!

The dermis is the layer of skin that contains blood vessels and sensory receptors. This layer lies beneath the epidermis and is essential for providing structural support to the skin. It houses a variety of structures, including connective tissue, hair follicles, sebaceous glands, and sweat glands. The presence of blood vessels in the dermis is critical for thermoregulation and the delivery of nutrients to the skin. Additionally, the sensory receptors located within the dermis allow for the detection of tactile stimuli, temperature changes, and pain, contributing to our sense of touch.

On the other hand, the epidermis, which is the outermost layer of skin, does not contain blood vessels or significant nerve endings; it primarily consists of keratinocytes and serves as a protective barrier against environmental damage. The hypodermis, located below the dermis, serves as an insulating layer and connects the skin to underlying tissues but is not considered a part of the skin itself. The stratum basale is a specific layer within the epidermis responsible for generating new skin cells, but it too lacks the vascular and sensory components found in the dermis.