BIO105 | BIO105 Anatomy and Physiology 1 Exam
1 Version 3 | Questions with Correct Answers and
Expert Explanation for Each Question | Saint Paul’s
School of Nursing
1. Which layer of the epidermis is responsible for the rapid cell division that produces
new keratinocytes?
A. Stratum basale
B. Stratum corneum
C. Stratum granulosum
D. Stratum spinosum
Correct Answer: A
Expert Explanation: The stratum basale is the deepest layer of the epidermis and
consists of a single row of stem cells. These cells undergo continuous mitosis to
replenish the layers above them. This layer is vital for the regeneration of the skin
surface every 25 to 45 days. Melanocytes and Merkel cells are also found within this
specific layer. Options like the stratum corneum consist of dead cells and do not
involve active division.
2. A patient presents with a burn that has resulted in blistering, pain, and damage to
both the epidermis and the upper portion of the dermis. How is this burn classified?
A. Second-degree burn
,B. First-degree burn
C. Third-degree burn
D. Fourth-degree burn
Correct Answer: A
Expert Explanation: Second-degree burns are characterized by damage to the
epidermis and the upper papillary region of the dermis. The presence of blisters is a
hallmark sign of this classification because fluid accumulates between the skin
layers. First-degree burns only affect the epidermis and usually only involve redness
and slight swelling. Third-degree burns are full-thickness burns that destroy the
entire dermis and nerve endings. Proper assessment of burn depth is critical for
determining the necessary clinical intervention.
3. Which cell type in the skin is primarily responsible for detecting light touch and
transmitting that information to sensory nerves?
A. Merkel cells
B. Melanocytes
C. Keratinocytes
D. Dendritic (Langerhans) cells
Correct Answer: A
,Expert Explanation: Merkel cells are located at the epidermal-dermal junction and
function as tactile sensory receptors. They associate with a disc-like sensory nerve
ending to detect light pressure. Keratinocytes provide structural integrity, while
melanocytes produce pigment for UV protection. Dendritic cells are immune cells
that ingest foreign substances rather than sensing touch. Understanding these
specialized cells is essential for grasping the integumentary system’s sensory
function.
4. The subcutaneous layer, also known as the hypodermis, is primarily composed of
which tissue types?
A. Stratified squamous epithelium
B. Dense irregular connective tissue
C. Hyaline cartilage
D. Adipose and areolar connective tissue
Correct Answer: D
Expert Explanation: The hypodermis serves as a storage site for fat and anchors
the skin to underlying structures like muscle. It consists mostly of adipose tissue,
which provides insulation and shock absorption for the body. Areolar tissue within
this layer allows for the skin to slide over deeper structures without tearing. This
layer is not technically considered part of the skin but is crucial for
, thermoregulation. The epidermis is epithelial, and the dermis is dense irregular
connective tissue, making other options incorrect.
5. Which pigment is the most significant contributor to skin color and provides
protection against ultraviolet (UV) radiation?
A. Hemoglobin
B. Carotene
C. Bilirubin
D. Melanin
Correct Answer: D
Expert Explanation: Melanin is produced by melanocytes and packaged into
melanosomes to protect keratinocyte nuclei from DNA damage. The amount and
type of melanin determine the variation in human skin tones. Carotene provides a
yellow-orange tint and is obtained from dietary sources like carrots. Hemoglobin
contributes a pinkish hue to fair skin due to oxygenated blood in dermal capillaries.
Failure to produce sufficient melanin increases the risk of skin cancers and sun-
related disorders.
6. What is the primary function of the sebaceous glands found in the dermis?
A. Secretion of oil (sebum) to lubricate skin and hair
B. Synthesis of Vitamin D
1 Version 3 | Questions with Correct Answers and
Expert Explanation for Each Question | Saint Paul’s
School of Nursing
1. Which layer of the epidermis is responsible for the rapid cell division that produces
new keratinocytes?
A. Stratum basale
B. Stratum corneum
C. Stratum granulosum
D. Stratum spinosum
Correct Answer: A
Expert Explanation: The stratum basale is the deepest layer of the epidermis and
consists of a single row of stem cells. These cells undergo continuous mitosis to
replenish the layers above them. This layer is vital for the regeneration of the skin
surface every 25 to 45 days. Melanocytes and Merkel cells are also found within this
specific layer. Options like the stratum corneum consist of dead cells and do not
involve active division.
2. A patient presents with a burn that has resulted in blistering, pain, and damage to
both the epidermis and the upper portion of the dermis. How is this burn classified?
A. Second-degree burn
,B. First-degree burn
C. Third-degree burn
D. Fourth-degree burn
Correct Answer: A
Expert Explanation: Second-degree burns are characterized by damage to the
epidermis and the upper papillary region of the dermis. The presence of blisters is a
hallmark sign of this classification because fluid accumulates between the skin
layers. First-degree burns only affect the epidermis and usually only involve redness
and slight swelling. Third-degree burns are full-thickness burns that destroy the
entire dermis and nerve endings. Proper assessment of burn depth is critical for
determining the necessary clinical intervention.
3. Which cell type in the skin is primarily responsible for detecting light touch and
transmitting that information to sensory nerves?
A. Merkel cells
B. Melanocytes
C. Keratinocytes
D. Dendritic (Langerhans) cells
Correct Answer: A
,Expert Explanation: Merkel cells are located at the epidermal-dermal junction and
function as tactile sensory receptors. They associate with a disc-like sensory nerve
ending to detect light pressure. Keratinocytes provide structural integrity, while
melanocytes produce pigment for UV protection. Dendritic cells are immune cells
that ingest foreign substances rather than sensing touch. Understanding these
specialized cells is essential for grasping the integumentary system’s sensory
function.
4. The subcutaneous layer, also known as the hypodermis, is primarily composed of
which tissue types?
A. Stratified squamous epithelium
B. Dense irregular connective tissue
C. Hyaline cartilage
D. Adipose and areolar connective tissue
Correct Answer: D
Expert Explanation: The hypodermis serves as a storage site for fat and anchors
the skin to underlying structures like muscle. It consists mostly of adipose tissue,
which provides insulation and shock absorption for the body. Areolar tissue within
this layer allows for the skin to slide over deeper structures without tearing. This
layer is not technically considered part of the skin but is crucial for
, thermoregulation. The epidermis is epithelial, and the dermis is dense irregular
connective tissue, making other options incorrect.
5. Which pigment is the most significant contributor to skin color and provides
protection against ultraviolet (UV) radiation?
A. Hemoglobin
B. Carotene
C. Bilirubin
D. Melanin
Correct Answer: D
Expert Explanation: Melanin is produced by melanocytes and packaged into
melanosomes to protect keratinocyte nuclei from DNA damage. The amount and
type of melanin determine the variation in human skin tones. Carotene provides a
yellow-orange tint and is obtained from dietary sources like carrots. Hemoglobin
contributes a pinkish hue to fair skin due to oxygenated blood in dermal capillaries.
Failure to produce sufficient melanin increases the risk of skin cancers and sun-
related disorders.
6. What is the primary function of the sebaceous glands found in the dermis?
A. Secretion of oil (sebum) to lubricate skin and hair
B. Synthesis of Vitamin D
