Clincial note: Despite keratinization, epidermis is permeable to many low molecular weight compounds. This allows transdermal administration of certain drugs, hormones, or nicotine via “skin patches”. This permeability is also the basis of contact dermatitis, an example of which is the skin’s reaction to compounds in the poison ivy plant.

Examine the dermis and hypodermis and identify the different types of tissues present.

• Identify Pacinian or lamellated corpuscles.
• Examine all the dermal papillae and identify any Meissner’s or tactile corpuscles present, although these are sometimes difficult to recognize in routinely stained sections.

Thin skin