Integumentary system Knowledge-Based Practice

Questions

1. 1.

   Which exocrine glands in the human skin release an oily lipid mixture by a holocrine mechanism, in which the entire secretory cell ruptures and disintegrates?

   • A) Eccrine sweat glands
   • B) Sebaceous glands
   • C) Apocrine sweat glands
   • D) Ceruminous glands
2. 2.

   Which compound present in the skin serves as the direct biochemical precursor that undergoes photolysis to produce cholecalciferol upon exposure to ultraviolet radiation?

   • A) Ergocalciferol
   • B) Calcitriol
   • C) 25-hydroxyvitamin D
   • D) 7-dehydrocholesterol
3. 3.

   Which specialized cells located within the epidermis act as antigen-presenting phagocytes to provide immune defense against pathogens that breach the skin barrier?

   • A) Melanocytes
   • B) Merkel cells
   • C) Langerhans cells
   • D) Keratinocytes
4. 4.

   Which physiological response occurs within the integumentary system to facilitate heat loss when core body temperature rises above normal?

   • A) Contraction of arrector pili muscles to elevate hair shafts
   • B) Vasoconstriction of dermal arterioles to reduce superficial blood flow
   • C) Increased lipid secretion by sebaceous glands to promote evaporative cooling
   • D) Dilation of dermal blood vessels and increased secretion by eccrine sweat glands
5. 5.

   Which epidermal layer of the human skin contains the actively dividing stem cells that continuously undergo mitosis to replenish the outer epithelial layers?

   • A) Stratum corneum
   • B) Stratum spinosum
   • C) Stratum basale
   • D) Stratum granulosum

Answers and step-by-step solutions appear after you finish the test.