neck muscles

The muscles of the neck region in a didactic way can be divided into 5 regions:

Anterior Neck Region:

PLATYSMA

Superior Insertion : Underside of mandible, skin of underside of face and corner of mouth

Inferior Insertion : Fascia covering the upper parts of the pectoralis major and deltoid muscles

Innervation : Cervical Branch of the Facial Nerve (7th cranial nerve)

Action : Pulls the lower lip and the buccal angle, partially opening the mouth (horror expression). Pulls the skin over the collarbone towards the jaw.

Hyoid Bone Region – Suprahyoid Muscles

1. DIGASTRIC

Upper Insert :

Anterior belly: digastric fossa of the mandible

Posterior belly: Mastoid process

Inferior Insertion : Body of hyoid bone

Innervation: Facial nerve (posterior belly) and Mandibular nerve (anterior belly)

Action : Elevation of the Hyoid Bone and Lowering of the Mandible (opening the mouth). The anterior belly pulls the hyoid bone forward and the posterior belly pulls it back.

2. STYLOID

Superior Insertion : Styloid process

Inferior Insertion : Body of hyoid bone

Innervation : Facial nerve (VII cranial nerve)

Action : Elevation and Retraction of the Hyoid Bone.

3. MYLOIODE

Superior Insertion : Mylohyoid line of mandible

Inferior Insertion : Body of hyoid bone

Innervation : Mandibular Nerve (Trigeminal nerve branch – V cranial nerve)

Action : Elevation of the hyoid bone and tongue.

4. GENIOID

I Superior insertion: Mentonian spine of mandible

Inferior Insertion : Body of hyoid bone

Innervation : Hypoglossal Nerve (C1)

Action: Anterior traction of the hyoid bone and tongue.

Hyoid Bone Region – Infrahyoid Muscles

1. STERNOHYOID

Superior Insertion : Body of hyoid bone

Lower Insertion : Back face of the
manubrium of the sternum and medial ¼ of the clavicle

Innervation : Branches of the Cervical Loop (N. of the Hypoglossal) with fibers from C1 to C3

Action : Lower the Hyoid Bone.

2. STERNOTHYROID

Superior Insertion : Thyroid cartilage

Inferior Insertion : Posterior surface of the manubrium of the sternum

Innervation : Branches of the Cervical Loop (N. of the Hypoglossal) with fibers from C1 to C3

Action : Lower Thyroid Cartilage

  3. THYROID

Superior Insertion: Greater horn of hyoid bone

Lower Insertion : Thyroid cartilage

Innervation : Hypoglossal nerve (C1 and C2)

Action : Lower the Hyoid Bone.

4. OMOYOIDEO

Superior Insertion : Body of hyoid bone

Lower Insertion : Upper border of scapula

Innervation : Branches of the Cervical Loop (N. of the Hypoglossal) with fibers from C1 to C3

Action : Lower the Hyoid Bone.

Lateral Region of the Neck

1. STERNOCLEIDOMASTOID

Superior Insertion : Mastoid process and superior nuchal line

Unilateral Contraction: Flexion, Homolateral Bending and Rotation with the face facing the opposite side

Bilateral Contraction: Head flexion.

2. PREVIOUS SCALENO

Superior Insertion: Anterior tubercles of the transverse processes of the 3rd to 6th cervical vertebrae

Inferior Insertion: Superior surface of 1st rib (anterior scalene tubercle)

Innervation : Branches of lower cervical nerves

Action : Elevation of the first rib and homolateral inclination of the neck – Inspiratory action.

3. MEDIUM SCALE

Superior Insertion : Anterior tubercles of the transverse processes of the 2nd to 7th cervical vertebrae

Inferior Insertion : Superior surface of 1st rib

Innervation : Branches of lower cervical nerves

Action : Elevation of the first Rib and Homolateral Tilt of the Neck – Inspiratory Action.

4. POSTERIOR SCALENO

Superior Insertion: Posterior tubercles of the transverse processes of the 5th to 7th cervical vertebrae

Lower Insertion : Upper border of 2nd rib

Innervation : Anterior branches of the last 3 cervical nerves

Action : Elevation of the second rib and ipsilateral inclination of the neck – Inspiratory action

5. SIDE RECTUS OF THE HEAD

Superior Insertion : Jugular process of occiput

Lower Insertion : Transverse process of atlas

Innervation : Branch of ansa cervicalis between the 1st and 2nd cervical nerves

Action : Homolateral head tilt.

Pre-Vertebral Region

 1. LONG OF THE HEAD

Superior Insertion : Basilar process of occiput

Inferior Insertion : Anterior tubercles of the transverse processes of the 3rd to 6th cervical vertebrae

Innervation : C1, C2 and C3

Action : Head flexion.

2. ANTERIOR RECTUS OF THE HEAD

Superior Insertion : Basilar process of occiput

Inferior Insertion : Transverse process and anterior surface of atlas

Innervation : Branch of ansa cervicalis between C1 and C2

Action : Flexion of the head.

3. NECK LONG

Superior Oblique Portion:

Superior Insertion : Tubercle of the anterior arch of the Atlas

Inferior Insertion : Anterior tubercle of the transverse processes of C3 and C5

Lower Oblique Portion:
Superior Insertion : Anterior tubercle of the transverse processes of C5 and C6

Lower Insertion : Vertebral bodies from T1 to T3

Vertical portion:
Superior Insertion : Vertebral bodies from C2 to C4

Lower Insertion : Vertebral bodies from C5 to T3

Innervation : Branches from C2 to C7

Action : Neck flexion and homolateral tilt

NECK MUSCLES Previous View

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000

NECK MUSCLES Side view

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

NECK MUSCLES Supra and Infrahyoid

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

NECK MUSCLES Supra and Infrahyoid

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

NECK MUSCLES geniohyoid

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

NECK MUSCLES mylohyoid

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

NECK MUSCLES Scalenes and Prevertebrals

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000 .