Question

how do nutrients reach the epidermis of the skin?

• blood vessels carry nutrients directly into the epidermis.
• diffusion transports nutrients from blood vessels in the dermis into the epidermis.
• nutrients migrate in vesicles from the hypodermis into the epidermis.
• solute pumping transports nutrients into the epidermis.

question 17

stratum lucidum is found in all types of skin covering the entire body.

• true
• false

Explanation:

Analyze epidermal nutrition

The epidermis is composed of keratinized stratified squamous epithelial tissue, which is avascular (lacks blood vessels). Because there are no blood vessels within the epidermis itself, it must rely on the underlying vascularized connective tissue of the dermis for its metabolic needs. Nutrients and oxygen leave the capillaries in the dermal papillae and travel by passive Epidermal Tissue Type diffusion through the extracellular fluid into the cells of the epidermis.

Evaluate nutrition options

• Blood vessels carry nutrients directly into the epidermis: Incorrect, because the epidermis is avascular.
• Diffusion transports nutrients from blood vessels in the dermis into the epidermis: Correct, as nutrients diffuse from the dermal capillaries across the basement membrane.
• Nutrients migrate in vesicles from the hypodermis into the epidermis: Incorrect, vesicular transport across multiple tissue layers is not the mechanism of tissue nourishment.
• Solute pumping transports nutrients into the epidermis: Incorrect, solute pumping (active transport) is a cellular-level mechanism, not the tissue-level transport mechanism for bulk nutrient delivery.

Analyze stratum lucidum distribution

The Epidermal Layers of the skin vary depending on whether the skin is classified as "thick skin" or "thin skin." The stratum lucidum is a thin, clear layer of dead keratinocytes found exclusively in thick skin, which is restricted to areas subject to high friction, such as the palms of the hands and the soles of the feet. Thin skin, which covers the rest of the body, lacks this layer. Therefore, the statement that the stratum lucidum is found in all types of skin covering the entire body is false.

Answer:

Question 1

• Blood vessels carry nutrients directly into the epidermis.
• Diffusion transports nutrients from blood vessels in the dermis into the epidermis. (Correct answer)
• Nutrients migrate in vesicles from the hypodermis into the epidermis.
• Solute pumping transports nutrients into the epidermis.

Question 2

• True
• False (Correct answer)