Axis (C2) vs Diaphragm
| Property | Axis (C2) | Diaphragm |
|---|---|---|
| Latin Name | Axis | Musculus diaphragma |
| Type | Bone | Muscle |
| Body System | Skeletal | Muscular |
| Body Region | Spine | Thorax |
| Function | The second cervical vertebra that provides a pivot point for rotation of the head. The dens (odontoid process) projects superiorly and acts as the axis around which the atlas rotates. | The primary muscle of respiration. Contraction flattens the dome-shaped muscle, increasing thoracic volume and creating negative pressure to draw air into the lungs during inspiration. |
| Clinical Significance | Odontoid fractures are common cervical spine injuries, especially in elderly patients. Hangman's fracture involves bilateral pars interarticularis fractures of C2. Atlantoaxial instability occurs in rheumatoid arthritis and Down syndrome. | Diaphragmatic hernias allow abdominal organs to enter the thoracic cavity. Phrenic nerve paralysis causes diaphragmatic elevation. Hiccups result from involuntary diaphragmatic spasms. |
| FMA ID | 12520 | 13295 |
Full structure pages
Axis (C2)
Axis
The second cervical vertebra, the axis provides the pivot around which the head rotates. Its defining feature is the dens, or odontoid process, a tooth-like projection that extends superiorly from the body to articulate with …