Longus colli muscle
The longus colli muscle is a prevertebral muscle of the neck that is innervated by the anterior rami of C2-C6 from the cervical plexus. Longus colli is a weak flexor the cervical spine and when contracting unilaterally it tilts and rotates the cervical spine to the ipsilateral side. Longus colli consists of upper (superior oblique), lower (inferior oblique) and central (vertical or intermediate) fibers.
On this page:
Summary
-
origin:
- upper fibers: anterior tubercles of the transverse processes of C3-C5
- central fibers: anterior surface of vertebral bodies of C5-T3 vertebrae
- lower fibers: anterior surface of vertebral bodies of T1-T3 vertebrae
-
insertion:
- upper fibers: anterior tubercle of C1 (atlas)
- central fibers: anterior surface of vertebral bodies of C2-C4 vertebrae
- lower fibers: anterior tubercles of the transverse processes of C5 and C6
- innervation: anterior rami of C2-C4 spinal nerves
- action: bilaterally longus capitis acts as a weak flexor of the head and cervical vertebrae alone unilateral action of the longus capitis muscle serves to rotate and tilt the cervical vertebrae and head to the ipsilateral side
Gross anatomy
Origin
The longus colli muscle has three distinct parts that originate from separate parts of the cervical and thoracic spine:
- superior oblique portion: originates from the anterior tubercles of the transverse processes of C3-C5 vertebrae
- vertical or intermediate part: arises from the anterior surfaces of the vertebral bodies of the C5-T3 vertebrae
- inferior oblique portion: originates from the anterior surfaces of the vertebral bodies of T1-T3 vertebrae
Insertion
The longus colli muscle has separate insertion sites for the anterior oblique, intermediate and inferior oblique parts of the muscle. The superior oblique fibers insert into the tubercle of the anterior arch of the atlas. The fibers of the vertical portion of the muscle travel directly upwards to insert on to the anterior surfaces of the vertebral bodies of C2-C4. Finally, the inferior oblique part of the longus colli muscle ascends laterally attaching on to the anterior tubercles of transverse processes of C5 and C6 cervical vertebrae.
Relations
The lateral border of the inferior oblique portion of the longus colli muscle meets the medial border of the scalenus anterior (anterior scalene) to form a pyramidal space whose apex meets over the carotid tubercle (or tubercle of Chassaignac). The carotid tubercle is the anterior tubercle of the transverse process of the sixth cervical (C6) vertebra and is an important landmark in identifying the carotid artery, which sits directly anterior to it. The floor of this pyramid is formed by the first part of the subclavian artery and within this pyramidal space lies the vertebral artery and the cervical sympathetic trunk with the stellate ganglion. In dissection of the neck, it should be noted that the cervical sympathetic chain lies on the lateral aspect of the longus colli muscle at the level of C6.
The phrenic nerve arises just above the carotid tubercle and descends vertically on the scalenus anterior muscle where it is overlapped by the lateral margin of the internal jugular vein.
Arterial supply
The longus colli muscle receives its blood supply from muscular branches of the ascending cervical artery and the inferior thyroid artery.
Innervation
The longus colli muscle is innervated segmentally by anterior rami of the C2 to C6 spinal nerves from the cervical plexus.
Action
The longus colli muscle works synergistically with longus capitis and scalene muscles as a weak flexor of the cervical spine. The action of the muscle is assisted greatly by gravity and by the powerful sternocleidomastoid muscles.
Related Radiopaedia articles
Anatomy: Head and neck
- skeleton of the head and neck
-
cranial vault
- scalp (mnemonic)
- fontanelle
-
sutures
- calvarial
- facial
- frontozygomatic suture
- frontomaxillary suture
- frontolacrimal suture
- frontonasal suture
- temporozygomatic suture
- zygomaticomaxillary suture
- parietotemporal suture (parietomastoid suture)
- occipitotemporal suture (occipitomastoid suture)
- sphenofrontal suture
- sphenozygomatic suture
- spheno-occipital suture (not a true suture)
- lacrimomaxillary suture
- nasomaxillary suture
- internasal suture
- basal/internal
- skull landmarks
- frontal bone
- temporal bone
- parietal bone
- occipital bone
- skull base (foramina)
-
facial bones
- midline single bones
- paired bilateral bones
- cervical spine
- hyoid bone
- laryngeal cartilages
-
cranial vault
- muscles of the head and neck
- muscles of the tongue (mnemonic)
- muscles of mastication
-
muscles of facial expression
- occipitalis muscle
- circumorbital and palpebral muscles
- nasal muscles
- buccolabial muscles
- elevators, retractors and evertors of the upper lip
- levator labii superioris alaeque nasalis muscle
- levator labii superioris muscle
- zygomaticus major muscle
- zygomaticus minor muscle
- malaris muscle
- levator anguli oris muscle
- risorius muscle
- depressors, retractors and evertors of the lower lip
- depressor labii inferioris muscle
- depressor anguli oris muscle
- mentalis muscle
- compound sphincter
- orbicularis oris muscle
- incisivus superior muscle
- incisivus inferior muscle
- muscle of mastication:
- elevators, retractors and evertors of the upper lip
- muscles of the middle ear
- orbital muscles
- muscles of the soft palate
- pharyngeal muscles
- suprahyoid muscles
- infrahyoid muscles
- intrinsic muscles of the larynx
- muscles of the neck
- accessory muscles of the neck
- deep cervical fascia
-
deep spaces of the neck
- anterior cervical space
- buccal space
- carotid space
- danger space
- deep cervical fascia
- infratemporal fossa
- masticator space
- parapharyngeal space
- stylomandibular tunnel
- parotid space
- pharyngeal (superficial) mucosal space
- perivertebral space
- posterior cervical space
- pterygopalatine fossa
- retropharyngeal space
- suprasternal space (of Burns)
- visceral space
- surgical triangles of the neck
- orbit
- ear
- paranasal sinuses
- nose
- oral cavity
- pharynx
- larynx
- viscera of the neck
- blood supply of the head and neck
-
arterial supply
-
common carotid artery
- carotid body
- carotid bifurcation
- subclavian artery
- variants
-
common carotid artery
- venous drainage
-
arterial supply
- innervation of the head and neck
-
cranial nerves
- olfactory nerve (CN I)
- optic nerve (CN II)
- oculomotor nerve (CN III)
- trochlear nerve (CN IV)
-
trigeminal nerve (CN V) (mnemonic)
- trigeminal ganglion
- ophthalmic division
- maxillary division
- mandibular division
- abducens nerve (CN VI)
- facial nerve (CN VII)
-
vestibulocochlear nerve (CN VIII)
- vestibular ganglion (Scarpa's ganglion)
- glossopharyngeal nerve (CN IX)
-
vagus nerve (CN X)
- superior laryngeal nerve
- recurrent laryngeal nerve (inferior laryngeal nerve)
- (spinal) accessory nerve (CN XI)
- hypoglossal nerve (CN XII)
- parasympathetic ganglia of the head and neck
- greater occipital nerve
- third occipital nerve
-
cervical plexus
- muscular branches
- longus capitis
- longus colli
- scalenes
- geniohyoid
- thyrohyoid
-
ansa cervicalis
- omohyoid (superior and inferior bellies separately)
- sternothyroid
- sternohyoid
- phrenic nerve
- contribution to the accessory nerve (CN XI)
- cutaneous branches
- muscular branches
- brachial plexus
- pharyngeal plexus
-
cranial nerves
- lymphatic drainage of the head and neck
- embryological development of the head and neck