Ribs (Bone)
Overview
There are 12 pairs of rib bones in the human body. These ribs structurally function to protect the vital organs but also serve as functional levers for respiration.
Articulations
Most of the ribs have a head, neck, and articular tubercle posteriorly which articulate with the costovertebral joints which consist of a costocorporeal joint and costotransverse joint1.
The costocorporeal joint connects the head of the rib to the costal demifacets of the two corresponding vertebrae and the intervertebral disc1.
The costotransverse joint refers to the articulation between the articular tubercle of the rib with the costal facet of the transverse process of the corresponding vertebrae1
Sternocostal joints
Function
Anatomy
The anterior aspect of the rib is composed of flattened hyaline cartilage1. Ribs 1-10 span from the spine posteriorly and span anteriorly to directly or indirectly connect to the sternum to complete the rib cage1. Ribs 1-7 articulate directly with the sternum via sternocostal joints1.
Head
The head of the rib makes up the distal aspect of the costocorporeal joint
Neck
Articular tubercle
Muscular attachments
| Muscles originating from the ribs | ||||
|---|---|---|---|---|
| Muscle | Origin | Insertion | Innervation | Action |
| Muscles inserting on the ribs | ||||
|---|---|---|---|---|
| Muscle | Origin | Insertion | Innervation | Action |
Ribs
1st
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
“Free floating rib”
12th
The 12th rib is considered a “Free floating rib” since it lacks attachment to the sternum