pectoralis major

The pectoralis major is a thick, fan-shaped muscle, situated at the upper front of the chest wall. It makes up the bulk of the chest muscles in the male and lies under the breast in the female. Underneath the pectoralis major is the pectoralis minor, a thin, triangular muscle. [WP,unvetted]. Every claim on this page comes from the Leumas anatomy graph and carries its source.

What the pectoralis major is

The pectoralis major is a thick, fan-shaped muscle, situated at the upper front of the chest wall. It makes up the bulk of the chest muscles in the male and lies under the breast in the female. Underneath the pectoralis major is the pectoralis minor, a thin, triangular muscle. [WP,unvetted]. The atlas records it as a muscle at the organ scale in the human body.

Where the pectoralis major is

It sits in the thorax and trunk, within the muscular system. Positioned deliberately as part of this species body plan.

What the pectoralis major connects to

The atlas records 7 typed relationships for it, across 5 kinds of connection. a kind of muscle of shoulder and pectoral muscle.

Supply and innervation

Innervation: thoracic nerve.

Also called

Also recorded as pectoralis major muscle, pectoralis major muscle structure and musculus pectoralis major. Searching any of those names reaches this page.

Source

Uberon multi-species anatomy ontology (Mungall et al.), CC BY 4.0. Term UBERON:0002381, version 2026-06-19, retrieved 2026-08-24. Licence: CC-BY-4.0.

• A kind of: muscle of shoulder and pectoral muscle.
• originates from: clavicle bone and sternum.
• Innervated by: thoracic nerve.
• inserts into: humerus.
• contains: skeletal muscle tissue of pectoralis major.

Questions

Where is the pectoralis major?

It sits in the thorax and trunk, within the muscular system. Positioned deliberately as part of this species body plan.

What does the pectoralis major connect to?

A kind of: muscle of shoulder and pectoral muscle.

Is the pectoralis major the same in other species?

Leumas holds the same relationship vocabulary for every species it carries, so where another dataset records this structure you can put the two side by side on /compare.