Axial Skeleton
Start with the big picture
The axial skeleton comprises 80 bones. Its skull includes 8 cranial bones and 14 facial bones; the hyoid and six auditory ossicles are also part of this system. The vertebral column is organized into cervical, thoracic, lumbar, sacral, and coccygeal regions, with characteristic curves and vertebral features. The atlas and axis have specialized structures, while intervertebral discs contribute to flexibility and shock absorption. The thoracic cage consists of the sternum and 12 pairs of ribs, classified as true, false, or floating. Together, these components provide the body’s central framework, protect important structures, and support functions such as respiration.
What you'll learn
- Identify the main components and bone counts of the axial skeleton.
- Distinguish the cranial and facial divisions of the skull and recognize major sutures.
- Describe vertebral column regions, curvatures, and typical vertebral features.
- Explain distinguishing features of the atlas, axis, and thoracic and lumbar vertebrae.
- Classify ribs and identify key structures of the thoracic cage.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
