Axis (C2) vs Biceps brachii
| Property | Axis (C2) | Biceps brachii |
|---|---|---|
| Latin Name | Axis | Musculus biceps brachii |
| Type | Bone | Muscle |
| Body System | Skeletal | Muscular |
| Body Region | Spine | Upper Arm |
| 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. | Primary supinator of the forearm and powerful flexor of the elbow. Also assists in shoulder flexion. The long head assists in shoulder joint stabilization. |
| 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. | Biceps tendon ruptures cause a visible bulge (Popeye deformity). Bicipital tendinitis causes anterior shoulder pain. The biceps reflex tests the C5-C6 nerve roots. |
| FMA ID | 12520 | 37670 |
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 …
Biceps brachii
Musculus biceps brachii
A two-headed muscle of the anterior compartment of the upper arm, the biceps brachii is the primary supinator of the forearm and a powerful flexor of the elbow, also assisting in flexion of the shoulder. …