Skeletal System & Bone Structure

The skeletal system provides support, protection, movement, and mineral storage for the human body. Understanding bone structure is essential for radiologic technologists because bone density, trabecular patterns, cortical thickness, and growth plate appearance all influence radiographic interpretation.

Students learn the microscopic and macroscopic organization of bone, including osteons, trabeculae, marrow cavities, periosteum, and the mineral matrix that gives bone its strength. Knowledge of bone development, remodeling, and pathology helps technologists identify abnormalities and optimize imaging techniques.

Summary: The skeletal system includes the microscopic and gross anatomy of bone, its development, remodeling, and pathology. Strengthen your understanding by reviewing General Anatomy, exploring imaging appearance in Radiographic Anatomy, and applying positioning concepts from Radiographic Positioning.


Bone Histology

Osteons

Cylindrical units of compact bone.

Lamellae

Concentric rings of mineralized matrix.

Lacunae

Small spaces housing osteocytes.

Canaliculi

Tiny channels for nutrient exchange.

Trabeculae

Spongy bone lattice providing strength.


Bone Development

Intramembranous Ossification

Forms flat bones like the skull.

Endochondral Ossification

Forms long bones from cartilage.

Epiphyseal Plates

Growth plates responsible for lengthening.

Primary & Secondary Centers

Ossification timing and patterns.


Bone Remodeling

Osteoblasts

Build new bone matrix.

Osteoclasts

Break down old bone tissue.

Wolff’s Law

Bone adapts to mechanical stress.

Calcium Homeostasis

Regulated by PTH, calcitonin, vitamin D.


Bone Pathology Basics

Osteoporosis

Reduced bone density and fragility.

Osteomalacia

Softening of bone due to vitamin D deficiency.

Paget’s Disease

Abnormal bone remodeling.

Metastatic Lesions

Common radiographic findings.


Fracture Classification

Simple vs Comminuted

One break vs multiple fragments.

Displaced vs Non-Displaced

Alignment differences.

Open vs Closed

Skin integrity involvement.

Salter-Harris

Pediatric growth plate fractures.


Pediatric vs Adult Bone Differences

Growth Plates

Visible in children, fused in adults.

Bone Flexibility

Children have more collagen.

Fracture Patterns

Buckle, greenstick, plastic deformation.

Marrow Composition

Red marrow decreases with age.


Major Skeletal System Websites

NIAMS

Bone health and research.

MedlinePlus Bones

Trusted bone anatomy information.

CDC Strong Bones

Bone development guidelines.

NHLBI

Marrow and skeletal physiology.

AO Foundation

Fracture management and bone biology.

Bone & Joint Journal

Orthopedic research.

AAOS

Orthopedic anatomy and pathology.

Teach Me Anatomy

Detailed bone structure lessons.

Visible Body Skeleton

3D skeletal models.

Khan Academy

Free skeletal system lessons.

OpenStax A&P

Free bone structure textbook.

PubMed

Bone research articles.

ScienceDirect

Bone structure studies.

NCBI Bookshelf

Free bone histology texts.

Radiology Masterclass

Bone imaging tutorials.

Learning Radiology

Bone pathology cases.

InnerBody

Interactive skeletal diagrams.

AnatomyTOOL

Open anatomy modules.