What type of cells make up the cutaneous membrane?
A. epithelial
B. muscle
C. adipose
D. none of these
The Correct Answer and Explanation is:
The correct answer is A. epithelial.
The cutaneous membrane, commonly known as the skin, is composed of two primary layers: the epidermis and the dermis. Each of these layers is made up of distinct types of cells with specialized functions.
- Epidermis: The outermost layer of the skin is primarily composed of epithelial cells. Specifically, the epidermis is made up of keratinized stratified squamous epithelium. This type of epithelium consists of multiple layers of cells, with the outermost layers being dead and filled with the protein keratin. The main types of epithelial cells in the epidermis include:
- Keratinocytes, which produce keratin and form the majority of the epidermal layer.
- Melanocytes, which produce the pigment melanin and contribute to skin color.
- Langerhans cells, which are involved in immune defense.
- Merkel cells, which are involved in sensory functions.
- Dermis: Beneath the epidermis lies the dermis, which is composed of connective tissue, not epithelial cells. The dermis contains collagen and elastin fibers, providing structural support and elasticity to the skin. It houses blood vessels, nerves, hair follicles, and glands such as sebaceous (oil) and sweat glands.
The subcutaneous layer, located below the dermis, consists mostly of adipose tissue (fat cells), providing insulation and energy storage, but it is not part of the cutaneous membrane itself.
Thus, the cutaneous membrane primarily consists of epithelial cells in the epidermis, which serve functions such as protection, sensation, and production of pigmentation. The dermis, though essential to the skin’s structure and function, is made up of connective tissue and is not composed of epithelial cells. Therefore, the correct answer is A. epithelial.