A&P 1 101 Module 7 Exam
Integumentary System — Portage Learning | 2026/2027 Edition
Total Questions: 28 | Time Allowed: 90 Minutes | Closed-Book,
Proctored Examination
DOMAIN 1: Epidermal Layers, Cell Types & Keratinization (10 Questions)
Question 1 (Multiple-Choice)
Which of the following lists the five layers of the epidermis in thick skin from deep to superficial
in the correct order?
A) Stratum Corneum, Lucidum, Granulosum, Spinosum, Basale
B) Stratum Basale, Spinosum, Granulosum, Lucidum, Corneum
C) Stratum Basale, Granulosum, Spinosum, Lucidum, Corneum
D) Stratum Spinosum, Basale, Granulosum, Lucidum, Corneum
Answer: B) Stratum Basale, Spinosum, Granulosum, Lucidum, Corneum [CORRECT]
Rationale: The epidermis of thick skin (found on the palms and soles) contains all five layers
arranged from deep to superficial as: Stratum Basale (deepest, site of mitosis), Stratum
Spinosum (thickest viable layer with desmosomes), Stratum Granulosum (where keratohyalin
and lamellar granules accumulate), Stratum Lucidum (clear layer found only in thick skin), and
Stratum Corneum (superficial layer of dead, keratinized squames). This sequence reflects the
progressive maturation and keratinization of keratinocytes as they migrate from the basal layer
toward the surface.
Question 2 (Fill-in-Blank / Labeling)
Label the five epidermal layers in the diagram below from DEEP to SUPERFICIAL. Write the
complete name of each layer in the space provided.
plain
Copy
[Superficial Surface]
, Layer 5: _________________________________
Layer 4: _________________________________
Layer 3: _________________________________
Layer 2: _________________________________
Layer 1: _________________________________
[Deep — Basement Membrane]
Answer:
• Layer 5: Stratum Corneum [CORRECT]
• Layer 4: Stratum Lucidum [CORRECT]
• Layer 3: Stratum Granulosum [CORRECT]
• Layer 2: Stratum Spinosum [CORRECT]
• Layer 1: Stratum Basale [CORRECT]
Rationale: The five layers of the epidermis in thick skin, ordered from deep to superficial, are:
(1) Stratum Basale — the deepest layer containing stem cells and melanocytes attached to the
basement membrane; (2) Stratum Spinosum — the thickest viable layer characterized by
desmosomes (spiny appearance) and Langerhans cells; (3) Stratum Granulosum — where
keratinocytes accumulate keratohyalin granules and lamellar granules, initiating the
keratinization process; (4) Stratum Lucidum — a thin, clear layer of dead cells found only in thick
skin; and (5) Stratum Corneum — the outermost layer composed of 20–30 layers of dead,
anucleate, keratinized squames that are continuously shed. This stratification is critical for the
skin's protective barrier function.
Question 3 (Multiple-Choice)
A histology student is examining a skin biopsy under the microscope and observes a layer where
cells contain prominent dark-staining granules and are undergoing programmed cell death.
Which epidermal layer is the student most likely observing?
A) Stratum Basale
B) Stratum Spinosum
C) Stratum Granulosum
D) Stratum Corneum
, Answer: C) Stratum Granulosum [CORRECT]
Rationale: The Stratum Granulosum is characterized by keratinocytes that contain dark-staining
keratohyalin granules (which aggregate keratin filaments) and lamellar granules (which release
glycolipids to waterproof the skin). In this layer, keratinocytes undergo apoptosis (programmed
cell death) as part of the keratinization process. The nuclei and organelles begin to degenerate,
and the cells flatten as they prepare to become the dead, keratinized cells of the Stratum
Corneum. This layer is typically 3–5 cell layers thick and represents the transition zone between
viable and non-viable epidermal cells.
Question 4 (True/False)
The Stratum Corneum is composed of living, nucleated keratinocytes that actively divide to
replace superficial cells.
Answer: FALSE [CORRECT]
Rationale: The Stratum Corneum is composed entirely of non-viable, dead, anucleate
keratinized squames (corneocytes) that lack nuclei and organelles. These cells are filled with
keratin protein and surrounded by a lipid matrix, forming the skin's primary physical and
chemical barrier. Cell division occurs only in the deepest layer, the Stratum Basale, where stem
cells undergo mitosis. The dead cells of the Stratum Corneum are continuously shed through
desquamation and replaced by cells migrating upward from deeper layers. This misconception is
common because the Stratum Corneum appears structurally intact, but it is functionally inert.
Question 5 (Multiple-Choice)
Melanocytes are derived from the neural crest and reside in the stratum basale. Which of the
following best describes the mechanism by which melanin protects keratinocytes from UV
radiation damage?
A) Melanin is retained within melanocytes and reflects UV rays away from the skin surface.
B) Melanin is transferred to keratinocytes via cytocrine secretion, where it accumulates as a
supranuclear cap to shield the nucleus from UV radiation.
C) Melanin is secreted into the extracellular matrix and diffuses across all epidermal layers to
absorb UV radiation.
D) Melanin is converted into vitamin D upon UV exposure, which then protects DNA from
mutation.
Integumentary System — Portage Learning | 2026/2027 Edition
Total Questions: 28 | Time Allowed: 90 Minutes | Closed-Book,
Proctored Examination
DOMAIN 1: Epidermal Layers, Cell Types & Keratinization (10 Questions)
Question 1 (Multiple-Choice)
Which of the following lists the five layers of the epidermis in thick skin from deep to superficial
in the correct order?
A) Stratum Corneum, Lucidum, Granulosum, Spinosum, Basale
B) Stratum Basale, Spinosum, Granulosum, Lucidum, Corneum
C) Stratum Basale, Granulosum, Spinosum, Lucidum, Corneum
D) Stratum Spinosum, Basale, Granulosum, Lucidum, Corneum
Answer: B) Stratum Basale, Spinosum, Granulosum, Lucidum, Corneum [CORRECT]
Rationale: The epidermis of thick skin (found on the palms and soles) contains all five layers
arranged from deep to superficial as: Stratum Basale (deepest, site of mitosis), Stratum
Spinosum (thickest viable layer with desmosomes), Stratum Granulosum (where keratohyalin
and lamellar granules accumulate), Stratum Lucidum (clear layer found only in thick skin), and
Stratum Corneum (superficial layer of dead, keratinized squames). This sequence reflects the
progressive maturation and keratinization of keratinocytes as they migrate from the basal layer
toward the surface.
Question 2 (Fill-in-Blank / Labeling)
Label the five epidermal layers in the diagram below from DEEP to SUPERFICIAL. Write the
complete name of each layer in the space provided.
plain
Copy
[Superficial Surface]
, Layer 5: _________________________________
Layer 4: _________________________________
Layer 3: _________________________________
Layer 2: _________________________________
Layer 1: _________________________________
[Deep — Basement Membrane]
Answer:
• Layer 5: Stratum Corneum [CORRECT]
• Layer 4: Stratum Lucidum [CORRECT]
• Layer 3: Stratum Granulosum [CORRECT]
• Layer 2: Stratum Spinosum [CORRECT]
• Layer 1: Stratum Basale [CORRECT]
Rationale: The five layers of the epidermis in thick skin, ordered from deep to superficial, are:
(1) Stratum Basale — the deepest layer containing stem cells and melanocytes attached to the
basement membrane; (2) Stratum Spinosum — the thickest viable layer characterized by
desmosomes (spiny appearance) and Langerhans cells; (3) Stratum Granulosum — where
keratinocytes accumulate keratohyalin granules and lamellar granules, initiating the
keratinization process; (4) Stratum Lucidum — a thin, clear layer of dead cells found only in thick
skin; and (5) Stratum Corneum — the outermost layer composed of 20–30 layers of dead,
anucleate, keratinized squames that are continuously shed. This stratification is critical for the
skin's protective barrier function.
Question 3 (Multiple-Choice)
A histology student is examining a skin biopsy under the microscope and observes a layer where
cells contain prominent dark-staining granules and are undergoing programmed cell death.
Which epidermal layer is the student most likely observing?
A) Stratum Basale
B) Stratum Spinosum
C) Stratum Granulosum
D) Stratum Corneum
, Answer: C) Stratum Granulosum [CORRECT]
Rationale: The Stratum Granulosum is characterized by keratinocytes that contain dark-staining
keratohyalin granules (which aggregate keratin filaments) and lamellar granules (which release
glycolipids to waterproof the skin). In this layer, keratinocytes undergo apoptosis (programmed
cell death) as part of the keratinization process. The nuclei and organelles begin to degenerate,
and the cells flatten as they prepare to become the dead, keratinized cells of the Stratum
Corneum. This layer is typically 3–5 cell layers thick and represents the transition zone between
viable and non-viable epidermal cells.
Question 4 (True/False)
The Stratum Corneum is composed of living, nucleated keratinocytes that actively divide to
replace superficial cells.
Answer: FALSE [CORRECT]
Rationale: The Stratum Corneum is composed entirely of non-viable, dead, anucleate
keratinized squames (corneocytes) that lack nuclei and organelles. These cells are filled with
keratin protein and surrounded by a lipid matrix, forming the skin's primary physical and
chemical barrier. Cell division occurs only in the deepest layer, the Stratum Basale, where stem
cells undergo mitosis. The dead cells of the Stratum Corneum are continuously shed through
desquamation and replaced by cells migrating upward from deeper layers. This misconception is
common because the Stratum Corneum appears structurally intact, but it is functionally inert.
Question 5 (Multiple-Choice)
Melanocytes are derived from the neural crest and reside in the stratum basale. Which of the
following best describes the mechanism by which melanin protects keratinocytes from UV
radiation damage?
A) Melanin is retained within melanocytes and reflects UV rays away from the skin surface.
B) Melanin is transferred to keratinocytes via cytocrine secretion, where it accumulates as a
supranuclear cap to shield the nucleus from UV radiation.
C) Melanin is secreted into the extracellular matrix and diffuses across all epidermal layers to
absorb UV radiation.
D) Melanin is converted into vitamin D upon UV exposure, which then protects DNA from
mutation.
