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ANATOMY

HEAD & NECK

Dr. Nawfal K. Al-Hadithi

Lec . 5

The Suprahyoid, Prevertebral,

Suboccipital Regions

By : Ali Kareem

مكتب اشور لالس تنساخ

2013 – 2014

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

Trachea :

• Begins at the cricoid cartilage (C6) & ends at the carinaT4 level, a

12 cm long tube ½ of which lies in the neck

• The CCA lie on each side of the trachea being separated from it

above by the lateral lobes of the thyroid.

• The oesophagus lies behind it & the intervening groove is occupied

by the recurrent laryngeal nerves

• Thyroid isthmus lies anterior to the rings 2-4
• Trachea is formed of C-shape cartilages opened behind & the

opening is closed by trachealis muscle.

• Cervical trachea is supplied by the inferior thyroid a., drained by

inferior thyroid v. , its nerve supply is similar to the thyroid gland
& its lymph goes to the postero-inferior group of deep cervical
nodes.

• Tracheostomy is a life-saving operation to open the airway in acute

& chronic airway obstruction.

• The incision is done below the cricoid cartilage & the trachea is

exposed after dividing the successive layers in front of it

• A tube is inserted to keep the airway patent

• 25 cm tube begins at the level of C6 vertebra (cricopharyngeus) &

ends at the cardiac opening of the stomach

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

• The carotid sheaths lie on each side being separated from it by the

posterior part of the lateral lobe of the thyroid.

• The trachea lies anterior to it & the intervening groove is occupied

by the recurrent laryngeal nerves

• The prevertebral muscles lie behind it with the sympathetic trunk

on each side.

• Cervical oesophagus is supplied by the inferior thyroid a., drained

by inferior thyroid v. , its nerve supply is similar to the thyroid
gland & its lymph goes to the postero-inferior group of deep
cervical nodes.

The submandibular triangle :
Is the space between the two bellies of digastric & the lower border of the
mandible.
Roof :

- Skin, subcutaneous connective tissue,

platysma and investing fascia.

Floor :

-  Myelohyoid “anteriorly”
-  Hyoglossus & part of the middle
-  constrictor “posteriorly”

Contents :
1- Suprahyoid muscles.
2- Submandibular gland.
3- Facial artery.
4- Common facial vein.
5- Submandibular lymph nodes.
6- Cervical branch of facial nerve.

Suprahyoid Muscles :

1- Digastric :

Origin :

- Anterior belly: From the digastric fossa at the lower border of the

mandible on each side of symphysis menti

- Posterior belly: From the digastric notch on the medial aspect of

the mastoid process.

Insertion :
The 2 bellies are directed to the body of the hyoid bone where they are
united by an intermediate tendon which is held to the hyoid bone by a
fibrous sling.
Nerve supply :

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

- Anterior belly : Nerve to myelohyoid (branch from the mandibular

n. Vc)

- Posterior belly : Facial nerve

Action :

- Elevate the hyoid bone, larynx & pharynx during swallowing
- Opens the mouth widely

2- Stylohyoid :

Origin :

- From the posterior aspect of the styloid process near its root.

Insertion :
The muscle descends superomedial & parallel to the posterior belly of
digastric to reach the intermediate tendon of digastric, here it divides into
2 slips which pass on each side of the intermediate tendon of digactric &
inserted on the hyoid bone near the greater horn.
Nerve supply :
Facial nerve
Action :

- Pulls the hyoid backward & upward.

3- Myelohyoid :

Origin :
From the whole length of myelohyoid line on the inner surface of the
mandible
Insertion :

- Fibers descend medially & backward
- Posterior part of it will reach the body of hyoid bone to which they

are inserted

- Anterior fibers meet each other in a midline raphe which extends

between the hyoid bone & the mandible

Nerve supply :
Nerve to myelohyoid (from the mandibular nerve Vc)
Action :

- Forms the floor of the mouth on which the tongue rests & move
- Plays a major role in swallowing.

4- Geniohyoid :

Origin :
Inferior genial tubercle.

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

Insertion :
The two ribbon like muscles descend side by side between myelohyoid &
genioglossus to be inserted into the upper border of the body of hyoid
bone.
Nerve supply :
C1 fibers from the XII nerve.
Action :
Pulls the hyoid anterosuperiorly.

5- Hyoglossus :
- This is a tongue muscle & is an important key around which the

structures of the floor of the mouth are distributed

Origin :
The upper border of the greater cornu of the hyoid.
Insertion :
The rectangular muscle ascends up to be inserted into the side of the
tongue posteriorly
Nerve supply :
XII nerve.
Action :

-  Pulls the hyoid up
-  Depresses the side of the tongue
-  Both retract the tongue

Submandibular gland :
Will be discussed later.

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

Facial artery :
Discussed.

Common facial vein :

• Formed at the lower border of the mandible by union of the

anterior facial v. & anterior division of retromandibular v.

• Passes superficial to the submandibular gland in the direction of

the carotid triangle of the neck

• Terminates in the IJV either separately or together with the

superior thyroid & lingual veins

• It drains the structures in the submandibular triangle

Submandibular lymph nodes :
Will be discussed later.

Cervical branch of VII :
Descends vertically from behind the mastoid process to platysma.

The submental triangle :
Is the space between the anterior bellies of the 2 digastrics & the hyoid
bone.

Roof :

- Skin, subcutaneous connective tissue, platysma and investing

fascia.

Floor :

- Myelohyoid

Contents :

1-  Submental branch of facial artery.
2-  Nerve to myelohyoid.
3-  beginning of AJV.
4-  Submental lymph nodes.

Submental branch of facial artery :
Discussed.

AJV :
Discussed.
Submental lymph nodes :

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

Will be discussed later.

Myelohyoid nerve :

• Given from the inferior alveolar nerve at the mandibular foramen.
• Pierces the sphenomandibular ligament & passes forward in the

floor of the submental triangle inferior to myelohyoid between it &
the anterior belly of digastric supplying both.

• It is accompanied by the submental artery.

The prevertebral region :
Is the area which lies in front of the vertebral column & constitutes the
prevertebral & paravertebral muscles covered by the prevertebral fascia.

Prevertebral Muscles :

Origin; lateral mass of atlas
Insertion; basi-occiput
Nerve supply; C1
Action; flexes the head

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

Origin; transverse process of atlas
Insertion; jugular process of occipital bone
Nerve supply; C1
Action; laterally flexes the head

Origin; anterior tubercles of T.P of the 4 typical cervical vertebrae end
to-end with the tendons of scalenus anterior
Insertion; basi-occiput anterior to foramen magnum
Nerve supply; C1-C4
Action; flexes the head & neck

This muscle extends on the anterior surface of the vertebral column from
C1 to C4
Origin;

-  Vertical part : bodies of thoracic vertebrae
-  Superior oblique part: T.P of upper cervical vertebrae
-  Inferior oblique part : bodies of upper thoracic vertebrae

Insertion;

-  Vertical part : bodies of cervical vertebrae
-  Superior oblique part : anterior tubercle of C1
-  Inferior oblique part : T.P of lower cervical vertebrae

Nerve supply; C1-T4
Action; flexes & rotates the neck

The Cervical Sympathetic Trunk :

• An upward extension of the thoracic S.T which is located behind

the carotid sheath on the prevertebral fascia

• In a cord-like form or multiple strands, the S.T develops three

ganglia in the neck; superior, middle & inferior

• Each one of the three has three sets of branches; somatic, vascular

& visceral.

• The body of the cervical S.T is formed mainly of preganglionic

fibers which traverse the white rami communicantes of the upper 5
thoracic segments

• Cervical S.T possesses no white rami communicantes attaching it

to the spinal nerves since there is no lateral gray column in the
cervical segments

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

Vascular br.

Visceral br.

Somatic br.

Position

Ganglion

-Carotid
sympathetic
plexus

-Superior
cervical cardiac
nerves
-The left to the
superficial
cardiac plexus
-The right to the
deep C.P

-Gray

rami

communicants
to

C1-C4

spinal nerves

-Largest (2.5-
3.5) cm long
-C2 level

Superior
C.G

-Inferior
thyroid sym.
Plexus

-Middle
cervical cardiac
nerves to the
deep C.P

-Gray

rami

communicants
to C5 & C6
spinal nerves

-Smallest
(1.3 cm) long
-C6 level

Middle
C.G

-Vertebral
sym. plexus

-Inferior
cervical cardiac
nerves to the
deep C.P

-Gray

rami

communicants
to C7 & C8
spinal nerves

-In

82%

fused

with

the

ganglion

form  the  the
stellate  gan.
on  the  neck
of the 1st rib

Inferior
C.G

Root of the neck :
- The root of the neck is based on the supra-pleural membrane which

inclines downward & forward with the inclination of the first rib

- Behind & inferior to the membrane lies the lung apices with their

cervical pleura

- In front & superior to the membrane lies structures of the root.
- The neck root is studied according to structure relation to scalenus

The triangular space “of Chassaignac” :

- It is the space bounded laterally by the medial border of scalenus

anterior, medially by the sloping lateral border of longus colli &
inferiorly by the neck of the 1st rib

- Its apex is the carotid tubercle (C6 T.P) against which the CCA can

be compressed

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

- It contains the 1st part of subclavian artery & the 6th cervical sym.

Ganglion

Anterior relations :

1- Phrenic nerve: passes vertically across the obliquity of the muscle

leaving its medial border inferiorly to pass to the thorax.

2- Vagus nerve: descends anterior & medial to the muscle to reach the

front of the subclavian artery & gives the recurrent laryngeal n.
around this vessel on the right side.

3- Ascending cervical artery: ascends from the inferior thyroid a. on

the muscle medial to the phrenic nerve.

4- Transverse cervical & suprascapular arteries: cross anterior to the

lower part of the muscle in their way to the posterior triangle.

5- IJV: lies anterior to the lower part of the muscle.
6- Subclavian vein: crosses the lower part of the muscle to meet the

IJV medial to it in the pyramidal space.

7- Deep cervical L.N: around the IJV, inferior nodes lie especially in

front of the muscle.

8- SCM: covers all the above structures.

Medial relations :

1- Vagus nerve.
2- Middle & inferior cervical sympathetic ganglia: lie in the

pyramidal space on the medial side of scalenus anterior connected
in front of the subclavian artery by the ansa subclavia.

3- First part of subclavian artery: with its three branches
4- Vertebral vein(s): leave the T.P of C7 & course forward to enter

the confluence of the subclavian v. & IJV.

5- Thoracic duct (on the left) & right lymph duct (on the right): arch

in the pyramidal space to enter the confluence of the subclavian v.
& IJV.

Posterior relations :

1- Roots of brachial plexus: as they emerge from the intervertebral

foramina to the posterior triangle, they lie superior to the
subclavian artery.

2- Second part of subclavian artery: behind the muscle on the 1st rib,

here it gives the costocervical axis.

Lateral relations :

1- Trunks of brachial plexus: in the posterior triangle.

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

2- Third part of subclavian artery: behind the prevertebral fascia in

the floor of the posterior triangle.

- The muscles of the back of the neck are enclosed by the

thoracolumbar fascia in the posterior compartment of which the
postvertebral muscles lie

- Externally the investing fascia wraps the whole neck

Back of the neck :

Ligamentum nuchae :
A strong, triangular sheet of fibrous tissue dividing the back of the neck
into two halves & provides an important origin for many muscles, it is
attached by its three borders to :

1-  The external occipital crest, superiorly.
2-  Tips of cervical spines & supraspinous ligaments, anteriorly.
3-  Posterior  free  border  to  which  the  investing  fascia  comes  from

either side of the neck to be attached.

Thoracolumbar fascia :

- A strong fascia attached to the spines & transverse processes of the

vertebral column enclosing within its two compartments the
muscles

- This arrangement persists in the the lumbar region, in the thoracic

& cervical regions the anterior lamella of the fascia disappears
leaving the middle & posterior lamellae only enclosing in between
the postvertebral muscles

Muscles of the back of the neck :

- Its name in latin means “bandage” revealing its shape & function
- The muscle lies deep to trapezius & covers the deep muscles of the

neck like a strap.

Origin: from ligamentum nuchae & spines of C6 & 7 with the
supraspinous ligaments.

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

Insertion: The muscle is directed upward & laterally & divided into two
parts :

- Splenius capitis; inserted into the deep part of mastoid & the

lateral 1/3 of the superior nuchal line.

- Splenius cervicis; inserted into the posterior tubercles of T.P of the

upper 3 cervical vertebrae.

Nerve supply: posterior rami of C2-C6.
Action: pulls the head back & laterally in the direction of the active
muscle. Both extend the neck.

- This group of muscles extend from the sacrum to the skull in the

form of three longitudinal parallel columns & occupy the posterior
compartment of lumbar fascia

- Some of them are inserted into various regions (lumbar & thoracic)

& some muscles belong to the head & neck.

- Their nerve supply is segmental

  Is the intermediate column of E.S
  Has three parts (thoracis, cervicis & capitis).
  Arise from T.P of lower vertebrae.

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

 Inserted into T.P. of higher vertebrae.
 Capitis muscle is inserted into the back of the mastoid process deep

to splenius & SCM.

 Occupy the medial column of the E.S
 Its limited to the thoracic (thoracis), cervical (cervicis) & head

(capitis)regions

 S. cervicis & thoracis arise from the T.P of all thoracic vertebrae

They are inserted into the spines of 4-6 vertebrae above. The highest
fibers of cervicis muscle are inserted into the undersurface of the spine of
axis
They extend the upper vertebral column & rotate it to the opposite side

 S. capitis arises from T.P of C7-T6

It is the largest muscle in the back of the neck,being inserted into the
occipital bone between the 2 nuchal lines medially
It is the most powerful skull extensor

The suboccipital muscles :

 Origin: spine of C2
 Insertion: the area between inferior nuchal line & foramen

magnum, laterally

 Origin: posterior tubercle of C1
 Insertion: the area between inferior nuchal line & foramen

magnum, medially

Head & Neck Dr. Nawfal K. Al-Hadithi

Anatomy

Lec. 5 The Suprahyoid, Prevertebral, Suboccipital Regions

  Origin: T.P of C1
  Insertion: the area between the two nuchal lines, lateral to
                   semispinalis capitis

 Origin: spine of C2
 Insertion: T. P of C1

The suboccipital triangle :
Is the triangle embraced by the supoccipital muscles except rectus capitis
posterior minor which lies medial to it.
Floor: the posterio atlanto-occipital membrane & posterior arch of atlas

Contents :

1-  Vertebral artery; in the floor.
2-  Suboccipital nerve, C1.
3-  Greater  occipital  nerve,  C2:  hooks  below  the  inferior  oblique  &

ascends in the roof of the triangle.

4- Occipital artery: ascends medially in the roof of the triangle in its

way to the scalp together with the greater occipital nerve.

Edited & Published by :

Ali Kareem