Coracobrachialis: Attachments, Function & 3D Anatomy

Educational draft · anatomical review pendingSources checked 19 October 2026. Prepared with AI assistance; not yet reviewed by a qualified anatomist. Not for diagnosis or treatment.

Proximal landmark: Coracoid process
Destination bone: Humerus
Joint crossed: Shoulder, not elbow
Motor nerve: Musculocutaneous nerve

Not a third head of biceps

Coracobrachialis is a separate muscle. It shares the coracoid origin region with the short head of biceps, but the two have different distal destinations.

Use the names in the structure list to compare them. Similar shapes or matching selection colors are not sufficient to identify a muscle.

Sources: Loyola anatomy

Coracoid process to humeral shaft

It begins at the scapular coracoid process and attaches to the medial humeral shaft around its middle.

Both bones are available here. Select Scapula to inspect the proximal context, then Humerus for the distal context; the attachment areas are not individually highlighted.

Sources: Arm anatomy tables

A shoulder action, not an elbow action

Coracobrachialis assists shoulder flexion and adduction. Its humeral attachment means it does not cross the elbow.

The source pose is fixed. Turning the camera does not raise the arm or rotate the humerus within the socket; the viewer does not simulate muscle contraction or shoulder mechanics.

Follow the visible endpoint before comparing it with biceps. A shared origin region does not imply that two muscles span the same joints.

Sources: Loyola anatomy

Musculocutaneous nerve and brachial supply

The musculocutaneous nerve supplies the muscle; branches of the brachial artery provide its arterial supply.

Nerves and vessels are not loaded in this subset, so the text describes connections you cannot select in the viewer.

This mesh cannot demonstrate a nerve’s route through the tissue or establish an individual branching pattern. No nerve passage is marked by the selection outline.

Sources: Loyola anatomy · Arm anatomy tables

Read the model

Explore coracobrachialis in 3D

Trace the isolated shape. Begin with Front, then use Oblique to inspect the selected muscle. Focus selection recenters it if the mesh has moved out of view.
Restore the attachment bones. Choose Show context, select Coracobrachialis and enable Fade others. Alternate with Scapula and Humerus to inspect its proximal and distal surroundings.
Compare the short head of biceps. Select Biceps brachii · short head from the list, then return to Coracobrachialis. Open the selected title to continue on the separate structure page.

What this model can—and cannot—show

BodyParts3D provides this right-sided surface model, not every anatomical variant. Colors distinguish structures; they are not tissue textures.

This shoulder-and-arm subset contains the three deltoid parts, coracobrachialis, clavicle, scapula and humerus. Rotator-cuff muscles are also available: supraspinatus, infraspinatus, teres minor and subscapularis. Joint capsule, cartilage, nerves and vessels are not loaded. This remains a partial regional study, not a complete shoulder model.

The regional elbow and forearm subsets do not contain coracobrachialis. Use this arm context for its comparison with biceps. Source segmentation does not show tendon fibers or anatomical variations.

A section tool is not available for this structure. The surface model does not reveal internal tissue architecture or represent a medical scan.

Sources and editorial status

This guide uses independently written explanations with links to the evidence behind them. Source checking and specialist anatomical review are separate steps; the latter is still pending.

Loyola University Chicago — LUMEN, Coracobrachialis
Coracoid origin alongside biceps, shoulder actions and named motor nerve. Root levels are not generalized.
Texas Tech University Health Sciences Center El Paso — Axilla, Posterior Shoulder, & Arm
Coracobrachialis row: medial mid-shaft humeral attachment and brachial arterial supply.

3D geometry and its separate license are credited beneath the viewer. References do not imply endorsement of this site.

Coracobrachialis