Question

6. Name the specific sub-layer of the epidermis where mitosis occurs. 7. Describe functions of the dermal papillae: 8. Identify and label the photographs of the skin model to compare thin vs. thick skin: dermis, stratum corneum, stratum basale, dermal papillae, Meissner's corpuscle, duct of the sudoriferous gland, stratum spinosum, arrector pili, sebaceous gland, stratum granulosum, hair root, stratum lucidum 9. List the differences between thin and thick skin. Thick skin Thin skin Structure Epidermal thickness Layers of the epidermis Presence/absence of hair Presence/absence of sebaceous glands Density of sudoriferous glands

Answer 1

6.) The specific sub-layer of the epidermis where mitosis occurs is the stratum basale or the basal layer.

7.) The functions of the dermal papillae:

• Dermal papillae plays an important role in the epidermal and dermal layers so that they adhere to each other.
• They are also vital in providing larger surface areas specially in thick skin which helps in nourishment of the epidermal layer.

8.) The diagram of the skin model on the left is of thin skin model and the diagram to the right is of thick skin model.
The various labeling of the thin skin model is as follows:
On the extreme left of the thin skin model:

• The topmost arrow corresponds to sebaceous gland
• The second arrow corresponds to hair root
• The last/third arrow corresponds to arrector pili

On the extreme right of the thin skin model:

• The topmost arrow corresponds to stratum corneum
• The second arrow corresponds to stratum granulosum
• The third arrow corresponds to stratum spinosum
• The last/fourth arrow corresponds to stratum basale
• The last/fifth arrow corresponds dermis

The various labeling of the thick skin model is as follows:
On the extreme left of the thick skin model:

• The topmost/first arrow corresponds to stratum corneum
• The second arrow corresponds to stratum granulosum
• The third arrow corresponds to stratum spinosum
• The fourth arrow corresponds to stratum basale
• The last/fifth arrow corresponds to dermis

On the extreme left of the thick skin model:

• The topmost/first arrow corresponds to stratum lucidum
• The second arrow corresponds to Meissner's corpuscles
• The third arrow corresponds to dermal papillae
• The last/fourth arrow corresponds to duct of sudoriferous gland

9.) Differences between thick and thin skin:

Structure	Thick skin	Thin skin
Epidermal thickness	Thicker	Thinner
Layers of the epidermis	5 layers	4 layers
Presence/absence of hair	Absent	Present
Presence/absence of sebaceous gland	Absent	Present
Density of sudoriferous gland	More dense	Less dense