Ribs

Definition

Ribs are curved bones that form the rib cage, providing structural support and protection to the thoracic cavity. They play a crucial role in respiration by aiding the expansion and contraction of the lungs.

5 Must Know Facts For Your Next Test

1. Humans typically have 12 pairs of ribs, totaling 24 individual ribs.
2. The first seven pairs of ribs are called 'true ribs' because they attach directly to the sternum through costal cartilages.
3. Ribs 8 to 10 are known as 'false ribs' because they do not attach directly to the sternum but rather connect to the cartilage of the rib above them.
4. Ribs 11 and 12 are termed 'floating ribs' as they do not attach to the sternum at all.
5. The primary function of ribs includes protecting vital organs such as the heart and lungs and assisting in breathing by providing structure for muscle attachment.

Review Questions

• How many pairs of true ribs does a typical human have?
• What distinguishes floating ribs from other types of ribs?
• Why are false ribs given their name?

Related terms

Sternum: A flat bone located in the center of the chest, connecting with true ribs via costal cartilages.

Thoracic Vertebrae: The twelve vertebrae in the middle section of the vertebral column that articulate with the rib cage.

Costal Cartilage: Bars of hyaline cartilage that extend from each rib and contribute to elasticity within the rib cage.