Skin Anatomy & Physiology Flashcards

What is the approximate pH range of healthy, intact skin surface?

Answer: 4.5–5.5

Normal skin has a slightly acidic pH of 4.5–5.5, forming the 'acid mantle' that inhibits microbial growth and maintains barrier function.

Melanin is synthesized from which amino acid precursor?

Answer: Tyrosine

Melanin biosynthesis begins with tyrosine, which is converted to DOPA and then dopaquinone by the enzyme tyrosinase in melanosomes.

Which cells in the skin are responsible for the immunological surveillance and antigen presentation?

Answer: Langerhans cells

Langerhans cells are dendritic antigen-presenting cells in the epidermis that capture antigens and present them to T-lymphocytes, playing a key immune role.

The stratum granulosum is named for the granules it contains, which are primarily:

Answer: Lamellar bodies and keratohyalin granules

The stratum granulosum contains keratohyalin granules (which form the keratin matrix) and lamellar bodies that release lipids to form the skin barrier.

In laser treatments, post-inflammatory hyperpigmentation (PIH) is most likely to occur in patients with:

Answer: Fitzpatrick Type IV–VI skin

Darker Fitzpatrick skin types (IV–VI) have more active melanocytes that are prone to overproducing melanin in response to thermal injury, causing PIH.

The subcutaneous layer (hypodermis) is composed mainly of:

Answer: Adipose tissue and loose connective tissue

The hypodermis consists primarily of adipose (fat) cells and loose connective tissue, providing insulation, energy storage, and cushioning.

Which sensory receptor in the skin is specifically associated with detecting light touch and located in dermal papillae?

Answer: Meissner's corpuscle

Meissner's corpuscles are encapsulated mechanoreceptors located in dermal papillae of fingertips and lips, specialized for detecting light touch and texture.