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Flat bones

Definition

Flat bones are made up of a layer of spongy bone between two thin layers of compact bone. They have a flat shape, not rounded. Examples include the skull and rib bones. Flat bones have marrow, but they do not have a bone marrow cavity.

Gallery

Skull
The skull is anterior to the spinal column and is the bony structure that encases the brain. Its purpose is to protect the brain and allow attachments for the facial muscles. The two regions of the skull are the cranial and facial region. The cranial portion is the part of the skull that directly houses the brain and the facial portion includes the rest of the bones of the skull.
Ribs and lung anatomy
The ribs are the skeletal protection for the lungs and the chest cavity. The ribs and rib muscles expand and contract with normal breathing.

References

Standring S. The skull. In: Standring S, ed. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 42nd ed. Philadelphia, PA: Elsevier; 2021:chap 34.

Standring S. Chest wall and breast. In: Standring S, ed. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 42nd ed. Philadelphia, PA: Elsevier; 2021:chap 53.

Last reviewed October 13, 2023 by Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team..

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