5. Integumentary System

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)?

Which type of cells play the most important role in preventing skin cancer?

Which epidermal cell can roam in and out of the epidermis?

Imagine you're a doctor, and a patient comes to you with a rare medical condition. It seems that their epidermal cells are not producing keratin. Which of the following symptoms are they most likely to experience?

The disease pemphigus vulgaris involves a patient's own immune system attacking the desmosomes between the epithelial cells of the skin. What changes would you expect to see with this disease?

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.

a. Melanocytes account for the bulk of the epidermis.

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

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

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

d. Merkel cells produce the pigment melanin.

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

a. The primary skin pigment is melanin, which is derived from the amino acid tyrosine.c

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

b. 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.

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

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

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