D312 A&P 1 WITH LAB - STUDY GUIDE SECTION 2 INTEGUMENTARY SYSTEM
MOST TESTED QUESTIONS AND ANSWERS GRADED A+ WITH RATIONALES
Which two layers make up the skin proper?
A. Epidermis and hypodermis
B. Epidermis and dermis ✔
C. Dermis and fascia
D. Stratum corneum and stratum basale
E. Hypodermis and fascia
Rationale: The skin proper contains the epidermis (outer) and dermis (deeper); the hypodermis
lies beneath.
What is the epidermis?
A. The vascular, inner layer of skin
B. The outer, avascular layer of skin ✔
C. The subcutaneous fat layer
D. The dermal papillae region only
E. The adipose membrane
Rationale: The epidermis is the superficial layer composed primarily of keratinocytes and lacks
blood vessels.
What is the dermis?
A. Outer dead cell layer
B. Layer immediately beneath the epidermis containing connective tissue, blood vessels, and
nerves ✔
C. Subcutaneous fat only
D. The cornified layer
E. Only sensory receptors
Rationale: The dermis houses vasculature, nerves, follicles, glands, and connective tissue.
What is the hypodermis?
A. Same as epidermis
B. Vascular portion of epidermis
C. Subcutaneous layer of skin composed mainly of fat and connective tissue ✔
D. The basal layer only
E. The epidermal ridge
Rationale: Hypodermis (subcutaneous) cushions, insulates, and anchors skin to underlying
tissues.
,ESTUDYR
Which pigments primarily determine skin color?
A. Melanin only
B. Hemoglobin only
C. Melanin, hemoglobin, and carotene ✔
D. Bilirubin and melatonin
E. Keratin and collagen
Rationale: Melanin (brown), hemoglobin (red tones), and carotene (yellow/orange) combine to
produce skin color.
Which is a major protective function of the skin?
A. Only vitamin D synthesis
B. Heat production only
C. Acts as chemical, biological, and physical barrier against pathogens and injury ✔
D. Produces immune cells only
E. Stores bile
Rationale: Skin provides multiple barrier defenses including physical barrier, acidic mantle, and
immune cells.
How does the skin contribute to thermoregulation?
A. By storing heat only in fat
B. By producing hormones
C. By controlling blood flow (vasodilation/vasoconstriction) and sweat production; up to
~80% of heat loss via skin ✔
D. By absorbing heat from bones
E. By bone remodeling
Rationale: Skin modulates heat loss through blood flow adjustments and sweating.
What does cutaneous sensation include?
A. Only pain and temperature
B. Only pressure and vibration
C. Touch, pressure, vibration, tickle, temperature, and pain ✔
D. Hormonal detection only
E. Only proprioception
Rationale: Skin contains receptors for multiple modalities of sensory input.
How does the skin participate in excretion?
A. Removes large protein wastes via sebum
B. Excretes small amounts of metabolic wastes (salts, urea) in sweat ✔
C. Excretes bile through pores
, ESTUDYR
D. Excretes oxygen only
E. Secretes red blood cells
Rationale: Sweat glands help remove minor metabolic wastes and regulate osmolarity.
What triggers vitamin D synthesis in skin?
A. Heat exposure only
B. Contact with water
C. Ultraviolet (UV) light exposure converting precursors to vitamin D ✔
D. Friction of skin surfaces
E. Low blood sugar
Rationale: UVB radiation converts 7-dehydrocholesterol in the skin to vitamin D precursor.
Which four cell types chiefly comprise the epidermis?
A. Keratinocytes, fibroblasts, chondrocytes, osteocytes
B. Keratinocytes, melanocytes, Langerhans cells, Merkel cells ✔
C. Adipocytes, macrophages, dendritic cells, myocytes
D. Erythrocytes, platelets, lymphocytes, neutrophils
E. Schwann cells, oligodendrocytes, astrocytes, microglia
Rationale: These four epidermal cells perform protection, pigment production, immune
surveillance, and touch sensation.
What is the main role of keratinocytes?
A. Produce pigment only
B. Immune surveillance only
C. Synthesize keratin and contribute to the skin’s waterproof barrier ✔
D. Act as sensory receptors only
E. Produce collagen
Rationale: Keratinocytes produce keratin and lipids, forming the barrier of the epidermis.
What do melanocytes do?
A. Produce keratin
B. Produce melanin granules that absorb UV and influence skin color ✔
C. Secrete sebum
D. Phagocytose bacteria only
E. Make vitamin D directly
Rationale: Melanocytes synthesize melanin and transfer pigment to keratinocytes for UV
protection.
What are Langerhans cells?
A. Melanin-producing cells