,BIOL251/BIOL 251 Human Anatomy & Physiology I w/Lab
Module 3 Exam | Portage Learning | 2026 Edition (PDF)
1. Which of the following correctly lists the five categories of bone shape?
A) Long, Short, Flat, Irregular, and Sesamoid
B) Long, Short, Broad, Irregular, and Sesamoid
C) Long, Short, Flat, Regular, and Sesamoid
D) Long, Short, Flat, Irregular, and Round
Correct Answer: Long, Short, Flat, Irregular, and Sesamoid
Rationale: Bones are classified by shape into five categories: long (e.g., femur), short (e.g., carpals), flat
(e.g., sternum), irregular (e.g., vertebrae), and sesamoid (e.g., patella). These categories are based on
gross appearance rather than size, and they help predict function and location.
2. Which of the following is a function of the skeletal system?
A) Protection of vital organs
B) Production of blood cells
C) Mineral storage
D) All of the above
Correct Answer: All of the above
Rationale: The skeletal system performs multiple critical functions: providing structural support,
protecting vital organs (e.g., the skull protects the brain), producing blood cells through hematopoiesis
in red bone marrow, and storing minerals such as calcium and phosphorus.
3. Which bone cells are responsible for bone resorption (breakdown)?
A) Osteoblasts
B) Osteocytes
C) Osteoclasts
,D) Chondrocytes
Correct Answer: Osteoclasts
Rationale: Osteoclasts are large, multinucleated cells responsible for bone resorption, breaking down
bone tissue to release minerals into the blood. Osteoblasts build bone, osteocytes are mature bone cells
that maintain the matrix, and chondrocytes are cartilage cells.
4. Which bone cells are responsible for bone formation?
A) Osteoclasts
B) Osteoblasts
C) Osteocytes
D) Chondrocytes
Correct Answer: Osteoblasts
Rationale: Osteoblasts are the bone-forming cells that secrete the organic matrix of bone and promote
its mineralization. They are essential for bone growth and repair. Osteoclasts break down bone,
osteocytes maintain the bone matrix, and chondrocytes are cartilage cells.
5. Mature bone cells that maintain the bone matrix are called:
A) Osteoblasts
B) Osteoclasts
C) Osteocytes
D) Osteoprogenitor cells
Correct Answer: Osteocytes
Rationale: Osteocytes are mature bone cells derived from osteoblasts that have become embedded in
the bone matrix. They maintain the mineral content of the matrix and act as mechanosensors, detecting
mechanical stress on the bone.
, 6. Which type of bone tissue is found at the ends of long bones and is composed of trabeculae?
A) Compact bone
B) Spongy (cancellous) bone
C) Periosteum
D) Endosteum
Correct Answer: Spongy (cancellous) bone
Rationale: Spongy (cancellous) bone is found at the ends of long bones (epiphyses) and consists of a
lattice of trabeculae. It is lightweight and provides structural support while housing red bone marrow for
hematopoiesis.
7. The structural unit of compact bone is the:
A) Osteon (Haversian system)
B) Trabecula
C) Canaliculus
D) Lacuna
Correct Answer: Osteon (Haversian system)
Rationale: The osteon, or Haversian system, is the structural unit of compact bone. It consists of
concentric rings of lamellae surrounding a central (Haversian) canal, which contains blood vessels and
nerves.
8. Which of the following is an example of a long bone?
A) Patella
B) Sternum
C) Femur
D) Vertebra
Module 3 Exam | Portage Learning | 2026 Edition (PDF)
1. Which of the following correctly lists the five categories of bone shape?
A) Long, Short, Flat, Irregular, and Sesamoid
B) Long, Short, Broad, Irregular, and Sesamoid
C) Long, Short, Flat, Regular, and Sesamoid
D) Long, Short, Flat, Irregular, and Round
Correct Answer: Long, Short, Flat, Irregular, and Sesamoid
Rationale: Bones are classified by shape into five categories: long (e.g., femur), short (e.g., carpals), flat
(e.g., sternum), irregular (e.g., vertebrae), and sesamoid (e.g., patella). These categories are based on
gross appearance rather than size, and they help predict function and location.
2. Which of the following is a function of the skeletal system?
A) Protection of vital organs
B) Production of blood cells
C) Mineral storage
D) All of the above
Correct Answer: All of the above
Rationale: The skeletal system performs multiple critical functions: providing structural support,
protecting vital organs (e.g., the skull protects the brain), producing blood cells through hematopoiesis
in red bone marrow, and storing minerals such as calcium and phosphorus.
3. Which bone cells are responsible for bone resorption (breakdown)?
A) Osteoblasts
B) Osteocytes
C) Osteoclasts
,D) Chondrocytes
Correct Answer: Osteoclasts
Rationale: Osteoclasts are large, multinucleated cells responsible for bone resorption, breaking down
bone tissue to release minerals into the blood. Osteoblasts build bone, osteocytes are mature bone cells
that maintain the matrix, and chondrocytes are cartilage cells.
4. Which bone cells are responsible for bone formation?
A) Osteoclasts
B) Osteoblasts
C) Osteocytes
D) Chondrocytes
Correct Answer: Osteoblasts
Rationale: Osteoblasts are the bone-forming cells that secrete the organic matrix of bone and promote
its mineralization. They are essential for bone growth and repair. Osteoclasts break down bone,
osteocytes maintain the bone matrix, and chondrocytes are cartilage cells.
5. Mature bone cells that maintain the bone matrix are called:
A) Osteoblasts
B) Osteoclasts
C) Osteocytes
D) Osteoprogenitor cells
Correct Answer: Osteocytes
Rationale: Osteocytes are mature bone cells derived from osteoblasts that have become embedded in
the bone matrix. They maintain the mineral content of the matrix and act as mechanosensors, detecting
mechanical stress on the bone.
, 6. Which type of bone tissue is found at the ends of long bones and is composed of trabeculae?
A) Compact bone
B) Spongy (cancellous) bone
C) Periosteum
D) Endosteum
Correct Answer: Spongy (cancellous) bone
Rationale: Spongy (cancellous) bone is found at the ends of long bones (epiphyses) and consists of a
lattice of trabeculae. It is lightweight and provides structural support while housing red bone marrow for
hematopoiesis.
7. The structural unit of compact bone is the:
A) Osteon (Haversian system)
B) Trabecula
C) Canaliculus
D) Lacuna
Correct Answer: Osteon (Haversian system)
Rationale: The osteon, or Haversian system, is the structural unit of compact bone. It consists of
concentric rings of lamellae surrounding a central (Haversian) canal, which contains blood vessels and
nerves.
8. Which of the following is an example of a long bone?
A) Patella
B) Sternum
C) Femur
D) Vertebra
