Which structure is highlighted in the cadaver skin?
?An illustration shows a sectional view of the layers of the skin, highlighting the middle layer and the structures in it.A line points toward the highlighted part in the illustration and the layer that is highlighted in a cadaver’s skin.
?© ?The McGraw-Hill Companies, Inc.
The correct answer and explanation is:
The highlighted structure in the cadaver’s skin is the dermis.
The dermis is the middle layer of the skin, located between the epidermis (the outermost layer) and the hypodermis (subcutaneous tissue). It is a thick, resilient layer that provides mechanical strength, elasticity, and support to the skin. The dermis is essential for the skin’s overall functionality and includes various components:
Key Features of the Dermis:
- Connective Tissue:
The dermis is composed primarily of collagen and elastin fibers, which provide structural integrity and elasticity. Collagen fibers give tensile strength, while elastin allows the skin to stretch and return to its original shape. - Blood Vessels:
Blood vessels in the dermis supply oxygen and nutrients to the skin and remove waste products. They also play a role in thermoregulation by controlling blood flow. - Sensory Receptors:
Specialized nerve endings in the dermis detect touch, pressure, pain, and temperature. This layer ensures the skin’s role as a sensory organ. - Sweat Glands and Sebaceous Glands:
Sweat glands help regulate body temperature through sweat production, while sebaceous glands secrete sebum to keep the skin hydrated and prevent microbial growth. - Hair Follicles and Arrector Pili Muscles:
Hair follicles extend into the dermis and are responsible for hair production. The arrector pili muscles attached to the follicles cause “goosebumps” when contracted. - Immune Cells:
The dermis contains immune cells that help defend against pathogens and initiate repair processes.
Explanation of the Dermis in Cadavers:
In cadavers, the dermis is typically more visible due to the removal of the epidermis during dissection. The dense collagen fibers give it a firm texture, while its vascular and glandular structures become prominent under closer examination. Understanding the dermis in cadaveric studies is crucial for medical students as it reveals the intricate organization of the skin’s supportive framework.