5. Integumentary System

What widespread effects does epidermal growth factor (EGF) have on the integument?

Beginning at the basement membrane and traveling toward the free surface, the epidermis includes the following strata:

(a) Corneum, lucidum, granulosum, spinosum, basale

(b) Granulosum, lucidum, spinosum, basale, corneum

(c) Basale, spinosum, granulosum, lucidum, corneum

(d) Lucidum, granulosum, spinosum, basale, corneum

Would you expect to find more keratin in keratinocytes closer to the external surface of the skin (more superficial) or further from the external surface of the skin (deeper)?

Identify the different portions (a–d) of the cutaneous membrane and the underlying layer of loose connective tissue (e) in the diagram to the right.

e. ____

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Dendritic cells are phagocytes of the immune system that protect the skin and deeper tissues from invasion by pathogens.

Keratinocytes in the superficial strata of the epidermis die because:

a. They are too far away from the blood supply in the dermis.

b. They are surrounded by a lipid-based substance that makes them more permeable to water.

c. They do not die.

d. No keratinocytes in the epidermis are alive.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The pigment hemoglobin in red blood cells gives skin a pinkish hue when it binds high amounts of oxygen.

What two major layers constitute the dermis, and what components are in each layer?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Melanin is produced by melanocytes and covers the nuclei of neighboring dendritic cells.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Carotene is a brown-black pigment that accumulates in the stratum corneum.

In clinical practice, drugs can be delivered by diffusion across the skin. This delivery method is called transdermal administration. Why are fat-soluble drugs more suitable for transdermal administration than drugs that are water soluble?

Which epidermal cells contain keratohyaline and lamellar granules?