BIOD 152 Essential Human Anatomy & Physiology I - Module 4:
Skeletal System 2026/2027 UPDATE
1. Which of the following is the structural unit of compact bone?
A. Trabecula
B. Canaliculus
C. Osteon
D. Lacuna
Answer: C
Rationale: The osteon (or Haversian system) is the fundamental functional unit of compact
bone, consisting of concentric layers of bone tissue.
2. Which part of a long bone is the primary site of longitudinal growth?
A. Diaphysis
B. Periosteum
C. Epiphyseal plate
D. Medullary cavity
Answer: C
Rationale: Longitudinal growth occurs at the epiphyseal plate (growth plate) through the
process of interstitial growth of cartilage.
,3. What type of bone cells are responsible for bone resorption (breaking down
bone)?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Osteogenic cells
Answer: C
Rationale: Osteoclasts are large, multinucleated cells that break down the bone matrix to
release minerals into the blood.
4. The shaft of a long bone is called the:
A. Diaphysis
B. Metaphysis
C. Periosteum
D. Epiphysis
Answer: A
Rationale: The diaphysis is the long, cylindrical main portion or shaft of a long bone.
5. Which type of bone development begins within a fibrous connective tissue
membrane?
A. Endochondral ossification
B. Intramembranous ossification
C. Appositional growth
D. Interstitial growth
Answer: B
Rationale: Intramembranous ossification is the process where bone forms directly from
mesenchymal tissue membranes, common in flat bones of the skull.
, 6. Yellow bone marrow is primarily composed of:
A. White blood cells
B. Red blood cells
C. Adipose tissue
D. Hyaline cartilage
Answer: C
Rationale: Yellow bone marrow consists mainly of adipose (fat) cells and serves as an
energy reserve.
7. Which hormone is released when blood calcium levels are too high?
A. Parathyroid hormone (PTH)
B. Calcitonin
C. Thyroxine
D. Estrogen
Answer: B
Rationale: Calcitonin, produced by the thyroid gland, helps lower blood calcium levels by
inhibiting osteoclasts and stimulating calcium deposition.
8. A fracture where the bone is broken into many small fragments is called:
A. Greenstick fracture
B. Comminuted fracture
C. Spiral fracture
D. Compound fracture
Answer: B
Rationale: A comminuted fracture is one in which the bone splinters or is crushed into
three or more pieces.
Skeletal System 2026/2027 UPDATE
1. Which of the following is the structural unit of compact bone?
A. Trabecula
B. Canaliculus
C. Osteon
D. Lacuna
Answer: C
Rationale: The osteon (or Haversian system) is the fundamental functional unit of compact
bone, consisting of concentric layers of bone tissue.
2. Which part of a long bone is the primary site of longitudinal growth?
A. Diaphysis
B. Periosteum
C. Epiphyseal plate
D. Medullary cavity
Answer: C
Rationale: Longitudinal growth occurs at the epiphyseal plate (growth plate) through the
process of interstitial growth of cartilage.
,3. What type of bone cells are responsible for bone resorption (breaking down
bone)?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Osteogenic cells
Answer: C
Rationale: Osteoclasts are large, multinucleated cells that break down the bone matrix to
release minerals into the blood.
4. The shaft of a long bone is called the:
A. Diaphysis
B. Metaphysis
C. Periosteum
D. Epiphysis
Answer: A
Rationale: The diaphysis is the long, cylindrical main portion or shaft of a long bone.
5. Which type of bone development begins within a fibrous connective tissue
membrane?
A. Endochondral ossification
B. Intramembranous ossification
C. Appositional growth
D. Interstitial growth
Answer: B
Rationale: Intramembranous ossification is the process where bone forms directly from
mesenchymal tissue membranes, common in flat bones of the skull.
, 6. Yellow bone marrow is primarily composed of:
A. White blood cells
B. Red blood cells
C. Adipose tissue
D. Hyaline cartilage
Answer: C
Rationale: Yellow bone marrow consists mainly of adipose (fat) cells and serves as an
energy reserve.
7. Which hormone is released when blood calcium levels are too high?
A. Parathyroid hormone (PTH)
B. Calcitonin
C. Thyroxine
D. Estrogen
Answer: B
Rationale: Calcitonin, produced by the thyroid gland, helps lower blood calcium levels by
inhibiting osteoclasts and stimulating calcium deposition.
8. A fracture where the bone is broken into many small fragments is called:
A. Greenstick fracture
B. Comminuted fracture
C. Spiral fracture
D. Compound fracture
Answer: B
Rationale: A comminuted fracture is one in which the bone splinters or is crushed into
three or more pieces.
