CDT Skin Anatomy & Physiology 3 — Questions and Answers
Question 1: The papillary dermis differs from the reticular dermis in that it contains:
- Densely packed Type I collagen bundles
- Loose connective tissue and capillary loops (Correct answer)
- Thick elastic fibers only
- Adipocytes and large vessels
Correct answer: Loose connective tissue and capillary loops
The papillary dermis is composed of loose connective tissue with capillary loops that nourish the avascular epidermis.
Question 2: Which cells in the skin are responsible for synthesizing and secreting melanin?
- Keratinocytes
- Fibroblasts
- Melanocytes (Correct answer)
- Mast cells
Correct answer: Melanocytes
Melanocytes are neural crest-derived cells located in the stratum basale that synthesize melanin in organelles called melanosomes.
Question 3: What is the primary function of the skin's stratum corneum?
- Immune surveillance
- Melanin production
- Barrier against water loss and pathogens (Correct answer)
- Sensory reception
Correct answer: Barrier against water loss and pathogens
The stratum corneum consists of dead, flattened corneocytes embedded in lipid lamellae that form the primary barrier against transepidermal water loss and external pathogens.
Question 4: Eccrine sweat glands open directly onto the skin surface and primarily serve to:
- Produce pheromones
- Regulate body temperature through evaporative cooling (Correct answer)
- Secrete sebum
- Produce milk in lactating women
Correct answer: Regulate body temperature through evaporative cooling
Eccrine glands secrete hypotonic sweat onto the skin surface where its evaporation dissipates heat and regulates core body temperature.
Question 5: The dermo-epidermal junction (DEJ) is composed primarily of which structural component?
- Type I collagen fibrils
- Basement membrane with Type IV collagen and laminin (Correct answer)
- Elastic fibers and fibrillin
- Hyaluronic acid and proteoglycans
Correct answer: Basement membrane with Type IV collagen and laminin
The DEJ (basement membrane zone) is composed of Type IV collagen, laminin, and other glycoproteins that anchor the epidermis to the dermis.
Question 6: Which layer of the skin is primarily responsible for thermoregulation and energy storage due to its adipose tissue content?
- Epidermis
- Papillary dermis
- Reticular dermis
- Hypodermis (Correct answer)
Correct answer: Hypodermis
The hypodermis (subcutaneous layer) contains adipocytes that store energy and insulate the body, contributing significantly to thermoregulation.
Question 7: Pacinian corpuscles are mechanoreceptors that detect:
- Light touch and texture
- Deep pressure and vibration (Correct answer)
- Temperature changes
- Pain and itch
Correct answer: Deep pressure and vibration
Pacinian corpuscles are encapsulated nerve endings in the deep dermis and subcutis that respond to deep pressure and high-frequency vibration.
CDT Skin Anatomy & Physiology 3
The papillary dermis differs from the reticular dermis in that it contains: