Question

the layer of skin that contains nerves, hair roots, sweat glands and blood vessels is called the—
○ hypodermis.
○ dermis.
○ fatty layer.
○ all of the above

Explanation:

• Hypodermis: Also known as the subcutaneous layer, it mainly consists of fat and connective tissue. While it has some blood vessels, its main function is insulation and energy storage, and it does not have hair roots and sweat glands in the same prominent way as the dermis.
• Dermis: This layer lies beneath the epidermis. It contains nerve endings (for touch, pain, etc.), hair follicles (where hair roots are located), sweat glands (eccrine and apocrine), and a rich network of blood vessels.
• Fatty layer (a description often related to hypodermis): As mentioned, it is not the layer with the main concentration of nerves, hair roots, and sweat glands.
• All of the above: Since hypodermis and fatty - layer (in the context of this question) do not have the full set of structures (nerves, hair roots, sweat glands, and blood vessels in the prominent way the dermis does), this option is incorrect.

Answer:

B. Dermis