Q: Which equation correctly represents the conversion of vitamin D in the body, starting from the skin?

$$\text{Skin: 7-dehydrocholesterol} \xrightarrow{UV~light} \text{Vitamin D}_3 \rightarrow \text{Liver: 25-hydroxyvitamin D}_3 \rightarrow \text{Kidney: 1,25-dihydroxyvitamin D}_3~(calcitriol)$$

Question 1

Which layer of the skin is primarily responsible for producing melanin, and what is the main function of melanin?

Accepted Answer

Stratum basale; protects against UV radiation

Question 2

A patient presents with a wound that exposes yellowish fatty tissue. According to wound management guidelines, which factor most strongly indicates the need for sutures?

Accepted Answer

The wound is deep enough to expose subcutaneous tissue

Question 3

Which of the following best describes the composition and function of sebum produced by sebaceous glands?

Accepted Answer

A mixture of triglycerides, cholesterol, proteins, and electrolytes; lubricates and protects hair and skin

Question 4

Which of the following changes in the integumentary system is most likely to increase the risk of overheating in elderly individuals?

Accepted Answer

Reduced activity of eccrine sweat glands

Question 5

A person with cyanosis will have a bluish skin color due to which physiological change?

Accepted Answer

Decreased oxygen levels in hemoglobin

Question 6

Which of the following is the correct sequence of events during skin repair after a superficial injury?

Accepted Answer

Blood clot forms, stratum basale cells migrate, macrophages remove debris, fibroblasts produce collagen

Question 7

Which equation correctly represents the conversion of vitamin D in the body, starting from the skin?

Accepted Answer

$$	ext{Skin: 7-dehydrocholesterol} \xrightarrow{UV~light} 	ext{Vitamin D}_3 ightarrow 	ext{Liver: 25-hydroxyvitamin D}_3 ightarrow 	ext{Kidney: 1,25-dihydroxyvitamin D}_3~(calcitriol)$$

Question 8

Which of the following statements about the epidermis is TRUE?

Accepted Answer

Cells with the highest metabolic demand are closest to the dermis

Question 9

A patient presents with irregularly shaped, multicolored, raised skin lesion greater than 5 mm in diameter. Which type of skin cancer is most likely?

Accepted Answer

Malignant melanoma

Question 10

Which accessory structure of the skin is responsible for detecting touch and pressure?

Accepted Answer

Root hair plexus

Question 11

Which of the following best explains why a serious burn can be life-threatening?

Accepted Answer

It disrupts homeostasis by causing fluid loss and increased risk of infection

Question 12

Which layer of the dermis is primarily responsible for providing strength and limiting flexibility?

Accepted Answer

Reticular layer

Question 13

Which pigment is most apparent in the stratum corneum of light-skinned individuals and is obtained from orange vegetables?

Accepted Answer

Carotene

Question 14

A patient with psoriasis is likely to show which change in their nails?

Accepted Answer

Distorted and pitted nails due to rapid stem cell division

Question 15

Which of the following is NOT a function of the integumentary system?

Accepted Answer

Production of insulin to regulate blood glucose

Question 16

Which of the following best describes the difference between thick and thin skin?

Accepted Answer

Thick skin is found on the palms and soles and has five layers; thin skin covers most of the body and has four layers

Question 17

Which of the following equations best represents the relationship between vitamin D and calcium absorption?

Accepted Answer

$$	ext{Calcitriol} ightarrow 	ext{Increased calcium and phosphorus absorption by small intestine}$$

Question 18

Which of the following is a plausible consequence of declining dendritic cell numbers in aging skin?

Accepted Answer

Decreased immune response

Question 19

Which of the following best describes the role of collagen fibers in the dermis?

Accepted Answer

They are strong, resist stretching, and limit flexibility to prevent damage

Chapter 5: The Integumentary System – Structure, Function, and Clinical Relevance

Guida di studio - Domande di pratica

Study guide - Flashcard