The Pre-Vertebral Muscles of the

Neck

Dr Ashraf Sadek PhD, MD, MRCPCH

Assistant Professor of anatomy and embryology

objects

1. Illustrate the anterior group of prevertebralmuscles

2. Illustrate the lateral group of prevertebralmuscles

3. Illustrate the muscles of the back of neck

4. Illustrate the boundaries and the content of sub-occipital

Triangle

BACK OF THE NECK

Skin of the nape (back of the neck and back of the scalp) is very thick and supplied by the dorsal rami of C2 (greater occipital nerve), C3 (third occipital nerve) and C4.

Dorsal ramus of C1 has no cutaneous distribution and is distributed only to the muscles bounding the suboccipitaltriangle.

Ligamentum Nuchae: It is a median triangular fibroelastic sheet. It extends from external occipital protuberance and crest to spine of the 7th cervical vertebra. It is the continuation of supraspinous and interspinousligaments in the cervical region

Muscles of the back could be divided into two main groups

Superficial extrinsic muscles. True deep intrinsic muscles.

They are separated by the thoracolumbar fascia which is replaced by the splenius muscles in the back of the neck.

The thoracolumbar fasciacovers the deep muscles of the back and

trunk

Medially: it attaches to the spinousprocesses of the thoracic vertebrae

Laterally: to the angles of the ribs. organization and integrity of the region

Superiorly, it continuous with deep fascia in the neck.

■ In the thoracic region, it covers the deep muscles and separates them from the muscles in the superficial and intermediate groups.

Superficial extrinsic muscles.

It comprises 3 layers of muscles which have the following features:

All are supplied by ventral rami and have no functional relation to the vertebral column.

They connects the appendicular and the axial Skelton.

First layer: Trapzius + latissimus dorsi.

Second layer: Levator scapulae + rhomboidusminor + rhomboidus major.

Third layer: serratus posterior superior + serratus posterior inferior.

The more superficial layers 1. the splenius muscles in the neck

and upper thorax

2. the erector spinae group in the trunk as a whole.

The deeper layers, include the transversospinal group, which is itself layered into 1. semispinalis2. multifidus3. the rotatores4. suboccipital muscles

Deepest of all

1. lie the interspinal2. inter-transverse muscles.

extend from the pelvis to the skull and are innervated by segmental branches of the posterior rami of spinal nerves

The intrinsic muscles are divided into superficial and deep layers.

the splenius muscle of the head (the splenius capitis)

OriginLower half of the ligamentum nuchae C4-C6.Spinous processes of C7-T4.

InsertionMastoid process and the rough surface of the adjoining occipital bone.

Action Extension of the neck and head bilaterally.Flexion of the neck and head unilaterally.Rotation of the head to the same side.

forms part of the floor of the posterior triangle of the neck.

The more superficial of the intrinsic muscles

OriginSpinous processes of T3-T6.

Insertionthe transverse processes of C1-C3.

actionExtension of the neck bilaterally.Flexion of the neck laterally.

the splenius cervicis(spinotransversales muscles)

The more superficial of the intrinsic muscles cont.

the erector spinae group

iliocostalis lumborum, longissimus thoracis, and spinalis thoracis.

in the trunk as a whole.

The more superficial of the intrinsic muscles cont.

transversospinal group, which is itself layered into 1. Semispinalis

2- multifidus

3- the rotatores

4- the suboccipital muscles

The deeper layers of intrinsic muscles

The deepest layers of intrinsic muscles

• Intertransverseii• interspinalis

Suboccipital muscleA small group of deep muscles in the upper cervical region at the base of the occipital bone move the head, connecting C1 vertebra to C2 vertebra and connect both vertebrae to the base of the skull

1-Rectus capitis posterior major. 2-Rectus capitis posterior minor. 3-Obliquus capitis inferior. 4-Obliquus capitis superior.

The four muscles lie deep to semispinaliscapitis.Contraction of the suboccipital muscles extends the head at the atlantoaxial joint. All these muscles, are supplied by, the suboccipital nerve (C1 ).

The deepest layers of intrinsic muscles cont.

DEEP MUSCLES IN THE NECK

• They are 2 groups of vertebral muscles that can bend the cervical vertebral column either forward in cases in pre-vertebral (anterior vertebral muscles)

• laterally in cases of scalene group (lateral vertebral muscles)

The anterior group (pre-vertebral muscles)

4 muscles cover the front of the vertebral column while they are covered by pre-vertebral fascia.

They extend from the base of the skull to the superior mediastinum.

Their nerve supply are ventral rami of cervical nerves

• Rectus capitis lateralis

• Rectus capitis anterior

• Longus capitis

• Longus colli (cervicis)

Rectus capitis lateralis

Origin: Upper surface of transverse process of C1.

insertion: Lower surface of occipital bone

Rectus capitis anterior

Origin: Anterior surface of lateral mass of C1

insertion: occipital bone in front of occipital condyles

Longus capitis

Longus colli (cervicis)

Lateral Vertebral Muscles (Scalene Muscles)

• A group of muscles (usualls 3 in number) extends from the transverse process of cervical vertebrae till the 1 st &2nd ribs to stabilize the neck.

• They extend obliquely like scaling ladders between the upper 2 ribs & cervical vertebral transverse processes.

• Their actions either flexing the cervical vertebrae laterally or elevate upper 2 ribs during inspiration

Scalenus anterior

Scalenus mediusscalenus posteriorScalenus minimus

Relation of Scalenus anterior

Anterior:

• Sternomastoid muscle• phrenic n• External jugular vein• Subclavian vein

Posterior: • Subclavian artery• Brachial pleuxes• Scalenus medius

Medial:• Vertebral artery

Thank you