BIOL251 Human Anatomy & Physiology I w/Lab | Latest
Update 2026/2027 | 200 Questions and Verified Answers |
Module 3 Exam Review | LockDown Browser Ready | A+
Graded
SECTION 1: THE INTEGUMENTARY SYSTEM (Questions 1–40)
1. Which layer of the skin is the outermost and serves as the primary barrier against the environment?
A) Dermis
B) Hypodermis
C) Epidermis
D) Subcutaneous layer
Correct Answer: C
Explanation: The epidermis is the outermost layer of the skin and serves as the primary physical,
chemical, and biological barrier. It is avascular (no blood vessels) and is composed mainly of
keratinocytes.
2. Which epidermal layer is found ONLY in thick skin (such as the palms and soles)?
A) Stratum spinosum
B) Stratum lucidum
C) Stratum granulosum
D) Stratum basale
Correct Answer: B
Explanation: The stratum lucidum is a clear, thin layer found only in thick skin areas such as the palms of
the hands and soles of the feet. It lies between the stratum granulosum and stratum corneum.
,3. What type of epithelium makes up the epidermis?
A) Simple squamous epithelium
B) Stratified squamous epithelium
C) Simple cuboidal epithelium
D) Transitional epithelium
Correct Answer: B
Explanation: The epidermis is composed of stratified squamous epithelium, which provides protection
against mechanical stress, pathogens, and water loss.
4. Which cells in the epidermis produce melanin?
A) Keratinocytes
B) Langerhans cells
C) Melanocytes
D) Merkel cells
Correct Answer: C
Explanation: Melanocytes are pigmentproducing cells found in the stratum basale of the epidermis.
They produce melanin, which protects the skin from UV radiation.
5. Which of the following is NOT a function of the integumentary system?
A) Protection against pathogens
,B) Regulation of body temperature
C) Synthesis of vitamin D
D) Production of red blood cells
Correct Answer: D
Explanation: Production of red blood cells (hematopoiesis) is a function of the skeletal system, not the
integumentary system. The integumentary system protects against pathogens, regulates temperature,
and synthesizes vitamin D.
6. The hypodermis is primarily composed of:
A) Dense irregular connective tissue
B) Adipose tissue and loose connective tissue
C) Stratified squamous epithelium
D) Hyaline cartilage
Correct Answer: B
Explanation: The hypodermis (subcutaneous layer) is primarily composed of adipose tissue and loose
connective tissue. It anchors the skin to underlying structures and provides insulation.
7. Which gland produces sweat that is primarily water with electrolytes and helps regulate body
temperature?
A) Sebaceous gland
B) Apocrine sweat gland
C) Eccrine sweat gland
D) Ceruminous gland
, Correct Answer: C
Explanation: Eccrine sweat glands produce a watery sweat that helps regulate body temperature
through evaporation. They are found throughout the body.
8. The protein that provides toughness and waterproofing to the skin, hair, and nails is:
A) Collagen
B) Elastin
C) Keratin
D) Melanin
Correct Answer: C
Explanation: Keratin is a tough, fibrous protein that provides structural strength and waterproofing to
the epidermis, hair, and nails.
9. Which layer of the epidermis is the deepest and contains actively dividing cells?
A) Stratum corneum
B) Stratum granulosum
C) Stratum spinosum
D) Stratum basale
Correct Answer: D
Explanation: The stratum basale (stratum germinativum) is the deepest layer of the epidermis. It
contains stem cells that continuously divide to produce new keratinocytes.
Update 2026/2027 | 200 Questions and Verified Answers |
Module 3 Exam Review | LockDown Browser Ready | A+
Graded
SECTION 1: THE INTEGUMENTARY SYSTEM (Questions 1–40)
1. Which layer of the skin is the outermost and serves as the primary barrier against the environment?
A) Dermis
B) Hypodermis
C) Epidermis
D) Subcutaneous layer
Correct Answer: C
Explanation: The epidermis is the outermost layer of the skin and serves as the primary physical,
chemical, and biological barrier. It is avascular (no blood vessels) and is composed mainly of
keratinocytes.
2. Which epidermal layer is found ONLY in thick skin (such as the palms and soles)?
A) Stratum spinosum
B) Stratum lucidum
C) Stratum granulosum
D) Stratum basale
Correct Answer: B
Explanation: The stratum lucidum is a clear, thin layer found only in thick skin areas such as the palms of
the hands and soles of the feet. It lies between the stratum granulosum and stratum corneum.
,3. What type of epithelium makes up the epidermis?
A) Simple squamous epithelium
B) Stratified squamous epithelium
C) Simple cuboidal epithelium
D) Transitional epithelium
Correct Answer: B
Explanation: The epidermis is composed of stratified squamous epithelium, which provides protection
against mechanical stress, pathogens, and water loss.
4. Which cells in the epidermis produce melanin?
A) Keratinocytes
B) Langerhans cells
C) Melanocytes
D) Merkel cells
Correct Answer: C
Explanation: Melanocytes are pigmentproducing cells found in the stratum basale of the epidermis.
They produce melanin, which protects the skin from UV radiation.
5. Which of the following is NOT a function of the integumentary system?
A) Protection against pathogens
,B) Regulation of body temperature
C) Synthesis of vitamin D
D) Production of red blood cells
Correct Answer: D
Explanation: Production of red blood cells (hematopoiesis) is a function of the skeletal system, not the
integumentary system. The integumentary system protects against pathogens, regulates temperature,
and synthesizes vitamin D.
6. The hypodermis is primarily composed of:
A) Dense irregular connective tissue
B) Adipose tissue and loose connective tissue
C) Stratified squamous epithelium
D) Hyaline cartilage
Correct Answer: B
Explanation: The hypodermis (subcutaneous layer) is primarily composed of adipose tissue and loose
connective tissue. It anchors the skin to underlying structures and provides insulation.
7. Which gland produces sweat that is primarily water with electrolytes and helps regulate body
temperature?
A) Sebaceous gland
B) Apocrine sweat gland
C) Eccrine sweat gland
D) Ceruminous gland
, Correct Answer: C
Explanation: Eccrine sweat glands produce a watery sweat that helps regulate body temperature
through evaporation. They are found throughout the body.
8. The protein that provides toughness and waterproofing to the skin, hair, and nails is:
A) Collagen
B) Elastin
C) Keratin
D) Melanin
Correct Answer: C
Explanation: Keratin is a tough, fibrous protein that provides structural strength and waterproofing to
the epidermis, hair, and nails.
9. Which layer of the epidermis is the deepest and contains actively dividing cells?
A) Stratum corneum
B) Stratum granulosum
C) Stratum spinosum
D) Stratum basale
Correct Answer: D
Explanation: The stratum basale (stratum germinativum) is the deepest layer of the epidermis. It
contains stem cells that continuously divide to produce new keratinocytes.
