Oblique Muscle of the Auricle

Ear · Head & Neck

The Oblique Muscle of the Auricle is a Head & Neck muscle within the Ear group. Originating at Cranial (medial) surface of the auricle over the upper part of the concha, it inserts at Cranial surface over the eminentia triangularis (above the concha). Its chief action is that it modifies the shape of the auricle (vestigial). Its nerve supply is the Posterior auricular branch of facial nerve (CN VII).

Origin, Insertion, Action & Nerve

Origin

Cranial (medial) surface of the auricle over the upper part of the concha

Insertion

Cranial surface over the eminentia triangularis (above the concha)

Action

Modifies the shape of the auricle (vestigial)

Nerve

Posterior auricular branch of facial nerve (CN VII)

Attachments explained

The Oblique Muscle of the Auricle is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.

Origin

Cranial (medial) surface of the auricle over the upper part of the concha

Insertion

Cranial surface over the eminentia triangularis (above the concha)

Action & function

When the Oblique Muscle of the Auricle contracts, it produces the following movement: Modifies the shape of the auricle (vestigial).

As part of the Ear group of the Head & Neck, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.

Nerve supply & clinical relevance

The Oblique Muscle of the Auricle receives its nerve supply from the Posterior auricular branch of facial nerve (CN VII).

Because a muscle can only contract when its nerve is intact, injury to the Posterior auricular branch of facial nerve can weaken or paralyse the Oblique Muscle of the Auricle, impairing the movements it normally produces (modifies the shape of the auricle (vestigial)). This is why knowing the innervation is central to localising nerve lesions in clinical practice.

How to study the Oblique Muscle of the Auricle (the OIANS method)

OIANS stands for Origin, Insertion, Action and Nerve, the four facts that uniquely define every skeletal muscle. To learn the Oblique Muscle of the Auricle, work through them in order: picture its origin, trace the muscle to its insertion, reason out the action that shortening between those two points must create, then add the nerve that drives it.

Most students remember the Oblique Muscle of the Auricle fastest by linking its action back to its attachments rather than memorising each fact in isolation. Once the origin and insertion make sense, the action usually follows logically.