Zygomaticus minor muscle
Musculus zygomaticus minor
Zygomaticus minor is a slender facial muscle passing from the cheekbone to the outer upper lip, which it lifts when smiling.
At a glance
- English
- Zygomaticus minor muscle
- Latin (TA2)
- Musculus zygomaticus minor
- System
- Muscle
- Region
- Head
- Side
- Paired, left and right
About the zygomaticus minor muscle
Zygomaticus minor is a small expression muscle at the front of the cheek. It is a narrow slip, only about half a centimetre wide, that runs from the cheekbone down and inwards to the upper lip. It lies between two neighbours that share its job: the stronger zygomaticus major sits lateral to it, and levator labii superioris lies medial. Older texts treated it as one head of levator labii superioris, calling it the zygomatic head.
The muscle starts on the outer surface of the zygomatic bone, just behind the zygomaticomaxillary suture. Its fibres slope downwards and medially at roughly thirty degrees and enter the lip towards its outer end, where they mix with orbicularis oris and the skin. In some people a few fibres also reach the side of the nostril. Its course may be straight or gently curved.
Contraction pulls the upper lip upwards, backwards and outwards. This exposes the upper teeth and deepens the upper part of the nasolabial fold, so the muscle helps shape a full smile and expressions of sadness or contempt. It is supplied by buccal branches of the facial nerve and receives blood from the facial artery, mainly through its superior labial branch.
The muscle is sometimes thin or poorly formed. When that happens, nearby lifters of the lip take over its role, and the difference in the smile is usually too small to see. Surgeons who reanimate the face after facial nerve paralysis, or who perform cosmetic lip and cheek work, take its position into account because it helps set the line of the upper lip.
Attachments, action and supply
- Origin
- Outer surface of the zygomatic bone, just behind the zygomaticomaxillary suture.
- Insertion
- Skin and muscle of the outer upper lip, blending with orbicularis oris.
- Action
- Raises the upper lip and draws it backwards and outwards, as in smiling.
- Nerve supply
- Buccal branches of the facial nerve (CN VII).
- Blood supply
- Facial artery, mainly its superior labial branch.
Anthromica
See the zygomaticus minor muscle where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
