BIOL 251 MODULE 4 EXAM: SKELETAL SYSTEM | BONE HISTOLOGY, AXIAL & APPENDICULAR IDENTIFICATION 2026 MODULE 4: THE SKELETAL SYSTEM QUESTIONS AND ANSWERS | PDF

BIOL 251 MODULE 4 EXAM: SKELETAL SYSTEM | BONE
HISTOLOGY, AXIAL & APPENDICULAR IDENTIFICATION 2026
MODULE 4: THE SKELETAL SYSTEM QUESTIONS AND
ANSWERS | PDF

Part 1: Bone Histology & Physiology
1. Which cell type is responsible for "building" new bone matrix?
 A) Osteocyte

 B) Osteoblast

 C) Osteoclast

 D) Chondrocyte

Explanation: Osteoblasts secrete osteoid (bone matrix). (Memory tip: Blasts Build).
2. What are the "giant, multinucleated" cells that break down bone matrix to
release calcium?
 A) Osteocytes

 B) Osteoblasts

 C) Osteoclasts

 D) Osteogenic cells

Explanation: Osteoclasts perform bone resorption. (Memory tip: Clasts Consume).
3. The structural unit of "Compact Bone" is called a(n):
 A) Trabecula

 B) Osteon (Haversian System)

 C) Canaliculus

 D) Lacuna

Explanation: An Osteon is a weight-bearing pillar consisting of a central canal
surrounded by concentric lamellae.

, 4. Where is "Red Bone Marrow" (the site of hematopoiesis) primarily found in
adults?
 A) Medullary cavity of long bones

 B) Spongy bone (Dipolë) of flat bones and epiphyses

 C) Central canals

 D) Periosteum

Explanation: Spongy bone contains trabeculae that house red marrow. In adults,
yellow marrow (fat) fills the medullary cavities of long bones.
5. The "shaft" of a long bone is anatomically known as the:
 A) Epiphysis

 B) Diaphysis

 C) Metaphysis

 D) Periosteum

Explanation: The Diaphysis is the long axis of the bone, while the Epiphyses are the
expanded ends.
6. Which hormone is released when blood calcium levels are LOW to stimulate
osteoclasts?
 A) Calcitonin

 B) Parathyroid Hormone (PTH)

 C) Growth Hormone

 D) Insulin

Explanation: PTH increases blood calcium by triggering bone resorption.
7. "Endochondral Ossification" describes bone developing from which
precursor?
 A) Fibrous membranes

 B) Hyaline cartilage

 C) Adipose tissue

,  D) Elastic fibers

Explanation: Most bones below the skull (except clavicles) form via Endochondral
ossification.
8. The "Epiphyseal Plate" is the site of:
 A) Bone thickness growth (appositional)

 B) Longitudinal bone growth (lengthening)

 C) Fracture repair

 D) Red marrow storage

Explanation: The Epiphyseal plate is a layer of hyaline cartilage in growing children; it
becomes the epiphyseal line once growth stops.
9. Which organic component provides bone with "flexibility" and tensile
strength?
 A) Calcium salts

 B) Collagen fibers

 C) Hydroxyapatites

 D) Phosphorus

Explanation: Collagen prevents bone from being too brittle. The mineral salts provide
hardness.
10. Tiny canals that connect lacunae to each other, allowing osteocytes to
communicate, are:
 A) Perforating canals

 B) Canaliculi

 C) Central canals

 D) Nutrient foramina

Explanation: Canaliculi ensure nutrients reach cells trapped in the hard matrix.


Part 2: The Axial Skeleton