Hyoglossus muscle
Musculus hyoglossus
The hyoglossus is a thin, flat tongue muscle rising from the hyoid bone into the side of the tongue, which it pulls down.
At a glance
- English
- Hyoglossus muscle
- Latin (TA2)
- Musculus hyoglossus
- System
- Muscle
- Region
- Head
- Side
- Paired, left and right
About the hyoglossus muscle
The hyoglossus is one of the extrinsic muscles of the tongue. It is a thin, four-sided plate placed on the side of the tongue, deep to the mylohyoid, and it is a key landmark in the floor of the mouth and the submandibular region because so many vessels and nerves are arranged on one side of it or the other.
Its origin is the hyoid bone: the lateral end of its body and the full length of the greater horn, with the fibres from the body overlapping those from the horn. It runs almost straight upwards into the lateral part of the tongue, where its fibres slip between the styloglossus, coming in from behind, and the intrinsic inferior longitudinal fibres. Part of it forms the floor of the submandibular triangle in the neck.
Its relations are worth learning in layers. On its outer surface, between it and the mylohyoid, lie from above down the sublingual gland, the lingual nerve, the submandibular duct, the hypoglossal nerve and its accompanying vein; the deep part of the submandibular gland also tucks into this gap behind. Towards the back the lingual nerve lies above the duct, then loops under it. On the deep, medial side of the muscle run the lingual artery, the glossopharyngeal nerve and the stylohyoid ligament. So the muscle keeps the lingual artery on its inner side while the hypoglossal nerve and its vein pass superficial to it, which is how the two are found apart in surgery.
When it contracts it pulls the sides of the tongue down and back towards the hyoid, depressing and retracting the tongue and making its upper surface more rounded. It helps in swallowing and in shaping the tongue for speech. It is supplied by the hypoglossal nerve and receives blood from the lingual artery, mainly from its dorsal lingual and sublingual branches.
Attachments, action and supply
- Origin
- Hyoid bone: lateral end of the body and the entire greater horn.
- Insertion
- Lateral part of the tongue, interleaved between styloglossus and the intrinsic inferior longitudinal fibres.
- Action
- Pulls the tongue down and back, rounding its dorsum.
- Nerve supply
- Hypoglossal nerve (cranial nerve XII).
- Blood supply
- Lingual artery, mainly its sublingual and dorsal lingual branches.
Anthromica
See the hyoglossus 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.
