Q: Which of the following equations best represents the conversion of 7-dehydrocholesterol to vitamin D3 in the skin upon UV exposure?

$7\text{-dehydrocholesterol} \xrightarrow{UV} \text{cholecalciferol (vitamin D}_3\text{)}$

Question 1

Which of the following best describes the main function of the stratum corneum in the epidermis?

Accepted Answer

It acts as a water barrier, preventing excessive water loss from the body.

Question 2

A patient presents with a burn that affects both the epidermis and the entire dermis, but not underlying tissues. How would this burn be classified?

Accepted Answer

Second-degree burn

Question 3

Keratinocytes originate in which layer of the epidermis and undergo mitosis before migrating upwards?

Accepted Answer

Stratum basale

Question 4

Which accessory structure of the integumentary system is primarily responsible for thermoregulation through excretion?

Accepted Answer

Sweat (sudoriferous) glands

Question 5

A topical medication is designed to be absorbed only by the superficial layers of the epidermis. Which property would make this possible?

Accepted Answer

The medication is polar and cannot pass through the lipid barrier.

Question 6

Which pigment is produced by melanocytes and provides protection against UV radiation?

Accepted Answer

Melanin

Question 7

If blood flow to the dermis is constricted for several hours, what is the most likely consequence for the epidermal cells?

Accepted Answer

Epidermal cells will receive less oxygen and nutrients, leading to cell death.

Question 8

Which layer of the epidermis is only found in thick skin, such as the palms and soles?

Accepted Answer

Stratum lucidum

Question 9

Which of the following equations best represents the conversion of 7-dehydrocholesterol to vitamin D3 in the skin upon UV exposure?

Accepted Answer

$7	ext{-dehydrocholesterol} \xrightarrow{UV} 	ext{cholecalciferol (vitamin D}_3	ext{)}$

Question 10

A needle is inserted into the epidermis of thin skin. What is the correct order of layers penetrated from superficial to deep?

Accepted Answer

Stratum corneum, stratum granulosum, stratum spinosum, stratum basale

Question 11

Which of the following statements about the epidermis is TRUE?

Accepted Answer

It is composed of keratinized stratified squamous epithelium.

Question 12

Which cell type in the epidermis is responsible for immune defense against pathogens?

Accepted Answer

Langerhans (dendritic) cells

Question 13

A patient with jaundice has yellowing of the skin. Which pigment is most likely responsible for this change?

Accepted Answer

Bilirubin

Question 14

Which of the following best explains why the epidermis is limited in thickness?

Accepted Answer

It relies on diffusion of oxygen and nutrients from the dermis.

Question 15

Which structure in the skin is responsible for forming fingerprints?

Accepted Answer

Dermal papillae

Question 16

Which of the following is a function of the integumentary system that helps maintain homeostasis?

Accepted Answer

Regulation of body temperature through sweat production

Question 17

Which layer of the dermis contains blood vessels, nerves, and adipose tissue?

Accepted Answer

Reticular layer

Question 18

A patient is exposed to excessive UV radiation. Which process in the skin helps protect against DNA damage?

Accepted Answer

Increased melanin synthesis by melanocytes

Question 19

Which of the following best describes the process of keratinocyte migration in the epidermis?

Accepted Answer

Keratinocytes originate in the stratum basale and migrate upward, flattening and accumulating keratin as they move.

Question 20

Which of the following equations best represents the relationship between skin thickness ($T$), rate of cell mitosis ($M$), and proximity to blood supply ($B$)?

Accepted Answer

$T \propto M 	imes B$

The Integumentary System: Structure, Function, and Clinical Relevance

Study Guide - Practice Questions

Study Guide - Flashcards