Using the key choices, choose all responses that apply to the following descriptions

Using the key choices, choose all responses that apply to the following descriptions. (Some choices may be used more than once.) Key: stratum basale stratum corneum stratum granulosum stratum lucidum stratum spinosum papillary layer reticular layer epidermis (as a whole) dermis (as a whole) 1. layer containing sacs filled with fatty material or keratin subunits 2. dead cells 3. the more superficial dermis layer 4. avascular region 5. major skin area where derivatives (nails and hair) are located 6. epidermal region exhibiting the most mitoses 7. most superficial epidermal layer 8. has abundant elastic and collagenic fibers 9. region where melanocytes are most likely to be found 10. accounts for most of the epidermis

The Correct Answer and Explanation is:

Here are the correct answers for each description:

1. Layer containing sacs filled with fatty material or keratin subunits
   Answer: Stratum granulosum, Stratum basale
   Explanation: The stratum granulosum contains keratinocytes that are filled with keratin, and stratum basale has cells that can store fat or other molecules as part of cellular metabolism.
2. Dead cells
   Answer: Stratum corneum
   Explanation: The stratum corneum is the most superficial layer of the epidermis and consists entirely of dead cells that have been keratinized (hardened and waterproofed).
3. The more superficial dermis layer
   Answer: Papillary layer
   Explanation: The papillary layer is the superficial layer of the dermis. It contains loose connective tissue and is responsible for forming the epidermal ridges (fingerprints).
4. Avascular region
   Answer: Epidermis (as a whole)
   Explanation: The epidermis is avascular, meaning it does not have blood vessels. The nutrients required by epidermal cells are supplied by diffusion from the underlying dermis.
5. Major skin area where derivatives (nails and hair) are located
   Answer: Dermis (as a whole)
   Explanation: The dermis houses structures such as hair follicles and sweat glands. While hair and nails extend through the epidermis, their roots and growth centers are located in the dermis.
6. Epidermal region exhibiting the most mitoses
   Answer: Stratum basale
   Explanation: The stratum basale is the deepest layer of the epidermis and is the site of continuous cell division (mitosis) to produce new skin cells.
7. Most superficial epidermal layer
   Answer: Stratum corneum
   Explanation: The stratum corneum is the outermost layer of the epidermis, consisting of dead cells that protect the skin.
8. Has abundant elastic and collagenic fibers
   Answer: Reticular layer
   Explanation: The reticular layer of the dermis is rich in collagen and elastic fibers, which provide strength and elasticity to the skin.
9. Region where melanocytes are most likely to be found
   Answer: Stratum basale
   Explanation: Melanocytes, which produce the pigment melanin, are primarily located in the stratum basale, the deepest layer of the epidermis.
10. Accounts for most of the epidermis
    Answer: Epidermis (as a whole)
    Explanation: The epidermis is the outermost layer of skin and constitutes the bulk of the outer protective layer of the body. The stratum corneum specifically, although superficial, makes up the most visible part of the epidermis.

These are the correct responses, and the explanation shows how each layer or region corresponds to its function or structure within the skin