Question 1

Which of the following best describes the main function of melanin in the skin?

Accepted Answer

It acts as a chemical barrier to protect DNA from ultraviolet (UV) radiation.

Question 2

A patient presents with blue-tinged skin (cyanosis). Which physiological condition is most likely responsible for this appearance?

Accepted Answer

Low oxygenation of hemoglobin in the blood

Question 3

Which layer of the epidermis is responsible for the continuous regeneration of skin cells, and how long does it typically take for a cell to migrate from this layer to the surface?

Accepted Answer

Stratum basale; 25-45 days

Question 4

A surgeon is planning an incision on the skin. Why is it important to consider cleavage (tension) lines in the dermis, and what is the expected outcome if the incision is made parallel to these lines?

Accepted Answer

Incisions parallel to cleavage lines heal more readily and with less scarring.

Question 5

Which of the following best explains why third-degree burns are often painless?

Accepted Answer

Nerve endings in the affected area are destroyed.

Question 6

A patient with polycystic ovary syndrome (PCOS) develops excessive hair growth (hirsutism). Which hormone is most likely elevated in this condition, and what is its effect on hair follicles?

Accepted Answer

Androgens; promote terminal hair growth

Question 7

Which of the following glands is primarily responsible for thermoregulation through sweat production, and what is the main composition of its secretion?

Accepted Answer

Eccrine (merocrine) sweat glands; 99% water with salts and metabolic wastes

Question 8

A patient presents with a yellowish skin tone (jaundice). Which organ system is most likely affected, and what is the underlying cause?

Accepted Answer

Liver; accumulation of bilirubin

Question 9

Which of the following best describes the role of dendritic (Langerhans) cells in the epidermis?

Accepted Answer

They activate the immune system by presenting antigens to white blood cells.

Question 10

A patient is exposed to organic solvents without gloves. Which of the following is a potential consequence, and why?

Accepted Answer

Kidney and brain damage due to absorption of toxic substances through the skin.

Question 11

Which pigment is responsible for the yellow to orange coloration of the skin, especially in the palms and soles, and can be converted to vitamin A?

Accepted Answer

Carotene

Question 12

A patient with a severe burn is at immediate risk for which of the following complications, and what is the physiological basis?

Accepted Answer

Electrolyte imbalance and dehydration due to loss of skin barrier function

Question 13

Which of the following best explains why elderly individuals are more prone to feeling cold and developing skin cancer?

Accepted Answer

Decreased subcutaneous fat and reduced melanocyte numbers

Question 14

Which of the following is a function of the papillary layer of the dermis?

Accepted Answer

Contains capillary loops and touch receptors that contribute to fingerprints

Question 15

A patient has a scaly, reddened papule on the scalp that is diagnosed as squamous cell carcinoma. Which epidermal cell type is primarily involved in this cancer?

Accepted Answer

Keratinocytes of the stratum spinosum

Question 16

Which of the following best describes the process of keratinization in the epidermis?

Accepted Answer

Cells in the stratum granulosum accumulate keratohyaline granules and begin to die.

Question 17

A patient presents with a black-and-blue mark (ecchymosis) after an injury. What is the underlying cause of this skin discoloration?

Accepted Answer

Clotted blood beneath the skin

Question 18

Which of the following best explains the difference between eccrine and apocrine sweat glands?

Accepted Answer

Eccrine glands are involved in thermoregulation and secrete watery sweat, while apocrine glands secrete a viscous, protein-rich sweat and are associated with body odor.

Question 19

A patient is diagnosed with male pattern baldness. Which hormone and genetic factor are primarily responsible for this condition?

Accepted Answer

Dihydrotestosterone (DHT) and a delayed action gene

Question 20

Which of the following equations best represents the calculation of the percentage of body surface area affected by burns using the Rule of Nines?

Accepted Answer

$$ 	ext{Total Burn Area} = (	ext{Number of affected sections} 	imes 9\%) + (	ext{genital area if affected} 	imes 1\%) $$

The Integumentary System: Structure and Function

Guida di studio - Domande di pratica

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