42. Which of the following skin layers lacks blood vessels?
Answer: C
The epidermis is the skin layer that lacks blood vessels.
The epidermis is the outermost layer of the skin and is avascular, meaning it does not contain blood vessels. This characteristic is important for its role in protection and barrier functions.
A) Hypodermis
The hypodermis, also known as the subcutaneous layer, is located beneath the dermis and is rich in blood vessels. It plays a crucial role in thermoregulation and serves as an energy reserve.
B) Reticular papillary
The reticular and papillary layers are parts of the dermis and contain blood vessels. The papillary layer, which is the uppermost part of the dermis, is particularly well vascularized, supporting the epidermis.
C) Epidermis
The epidermis is the correct answer as it is the outermost layer of skin and lacks blood vessels. Instead, it receives nutrients through diffusion from the underlying dermis.
D) Dermis
The dermis is the layer of skin that lies beneath the epidermis and is highly vascularized. It contains blood vessels, nerves, and connective tissue, playing a vital role in the skin's structure and function.
Conclusion
The epidermis is definitively the layer of skin that lacks blood vessels, distinguishing it from the hypodermis, reticular papillary, and dermis, all of which contain blood vessels. This fundamental aspect of the epidermis is essential for its protective functions, as it allows for a barrier that is relatively independent of the vascular system beneath it.