Final answer:
Dermal thickening involves increased production of connective tissue in response to strain from activities or damage. Aging can decrease the skin's ability to regenerate, leading to a thinner epidermis, but certain stimuli can cause the dermis to thicken over time.
Step-by-step explanation:
The level of response of dermal thickening relates to various factors, including cell division, metabolic activity, and hormonal levels which can decrease as a person ages. However, in response to certain conditions, such as increased muscle activity, weight-lifting exercises, or damage, the dermis can thicken. This thickening involves increased production of connective tissue, which strengthens the dermis and allows it to handle added strain. Contact dermatitis and delayed-type hypersensitivity are examples of dermatological responses which might lead to an inflammatory reaction in the dermis and sometimes a subsequent increase in dermal thickness in response to chronic damage.