Chapter 28: Basic Sciences

Renewal of the epidermis takes approximately:

A. 13 to 14 days

B. 1 to 14 days

C. 14 to 26 days

D. 26 to 28 days

E. 28 to 32 days

D. It takes 13 to 14 days for maturation of keratinocytes from the basal layer to the corneum and another 13 to 14 days for shedding.

Fibulin-2 is capable of binding

A. Fibrinogen

B. Versican

C. Aggrecan

D. All of the above

E. None of the above

D. Fibulins are calcium-binding extracellular matrix proteins that do not form large aggregates but are capable of joining other supramolecular structures. Fibulin-2 is capable of binding fibrinogen, fibronectin, nidogen, PGs, aggrecan, and versican.

Stratum lucidum is a layer present between the granular and cornified layer found in:

A. Palmoplantar skin

B. Mucosa

C. Nail

D. Axillary skin

E. Scalp skin

A. The layer appears as an electronlucent zone and contains nucleated cells.

Seventy percent of the cornified cell envelope consists of:

A. Profillagrin

B. Loricrin

C. Involucrin

D. Filaggrin

E. Keratin

B. Loricrin accounts for the majority of proteins in the cornified cell envelope. It is insoluble and is highly hydrophobic. It is cross-linked by transglutaminase-3 to form homodimers and heterodimers with other proteins to increase solubilization.

Krause end bulbs or mucocutaneous end organs are found in:

A. Mucocutaneous junction

B. Hands and soles

C. Nipples/areola

D. Scalp skin

E. Nail apparatus

A. These structures are found at the vermillion border of the lips, glans penis, and clitoris.

Which is the only protein known to ...