How to Number Human Ribs

Your ribs articulate with your vertebral column posteriorly.
••• leonello/iStock/Getty Images

Your 12 pairs of ribs protect your heart, lungs and other vital organs of your thorax, or chest cavity. Anatomists have numbered the ribs from top to bottom, and different pairs have additional features that allow you to distinguish them from one another.

Atypical Ribs

Rib 1 is unusually short and wide, and has only one articular facet head for attachment to the spinal column; ribs 2 through 10 have two. Rib 2 has a characteristic roughened area on its upper surface, where a muscle called the serratus anterior joins it. Ribs 11 and 12, lack necks and also have only one articular facet each.

Anterior Attachments

Your first seven ribs attach in the front of your chest to the sternum, or breastbone. The next three attach to the cartilage of the ribs above them. The last two don't attach to anything, and are therefore sometimes called "floating ribs."

Related Articles

Human Anatomy Projects
Description of the Anatomy of a Human Finger
What Parts Make Up the Human Leg?
How to Study the Bones in the Human Skeleton
Facts About the Human Skull for Kids
Anatomy of the Ligaments in the Forearms
The Skeletal System of Mammals
The Major Components of the Skeletal System
Three Types of Fibrous Connective Tissue
Human Anatomy Projects
How to Make a Human Liver Model
How to Know If an Ascaris Is a Male or Female?
What Is the Purpose of the Fibrous Capsule?
How to Build a Knee School Project
How to Make DNA Models of Paper Clips
How to Learn the Parts of the Human Skull
How to Make a Human Heart Out of Pop Bottles
How to Make a 3D Hexagon
Differences Between a Cat, Dog, & Human Skeleton