SIDE OF THE NECK (deep cervical fascia) AND POSTERIOR TRIANGLE OF NECK Anatomy

1. SIDE OF THE NECK AND
POSTERIOR TRIANGLE
Dr. Amaan

2. SIDE OF NECK
BOUNDARIES – It is roughly quadrilateral in
outline.
• Anteriorly – by anterior median line,
• Posteriorly – by the anterior border of trapezius
• Superiorly – by the base of mandible, a line
joining angle of mandible to mastoid process
and superior nuchal line
• Inferiorly – by clavicle

3. .
This quadrilateral space is divided obliquely by the
Sternocleidomastoid muscle (SCM) into –
• Anterior triangle and
• Posterior triangle

4. BOUNDARIES

5. It consists of -
(1) Skin
(2) Superficial fascia
(3) Deep fascia ( Fascia Colli) –
1. Investing layer (forms the capsule of the
Parotid gland)
2. Pretracheal layer
3. Prevertebral layer
4. Carotid Sheath
5. Buccopharyngeal fascia (over buccinator)
6. Pharyngobasilar fascia

6. (1) SKIN
• Skin of the neck is supplied by the –
C2, C3 and C4 nerves.
• Anterior part is supplied by – anterior primary
rami.
• Posterior part is supplied by – posterior primary
rami.

7. (2) SUPERFICIAL FASCIA
• Contains areolar tissue with platysma.
Deep to the platysma are –
Cutaneous nerves, superficial veins, lymph
vessels, lymph nodes, and small arteries

8. Investing layer of
deep cervical fascia
Platysma m.

9. (3) Deep fascia ( Fascia Colli) –
The deep fascia of the neck is condensed to
form the following layers-
1. Investing layer
2. Pretracheal layer
3. Prevertebral layer
4. Carotid Sheath
5. Buccopharyngeal fascia
6. Pharyngobasilar fascia

10. 1 . Investing layer
• It lies deep to platysma,
• Surrounds the neck like a collar,
• it forms the roof of the posterior triangle.
between the angle of mandible and the
mastoid process, the fascia splits to enclose the
parotid gland.
• Superficial lamina – thick and dense, forms
parotid fascia
• Deep lamina – thin, forms stylomandibular
ligament

11. .
• The investing layer of deep cervical fascia splits
to enclose:
1. Muscles – trapezius and SCM
2. Salivary glands – parotid and sub mandibular
3. Spaces – suprasternal and supraclavicular

12. 1. Investing fascia
SCM
4. Carotid sheath
2. Pretracheal fascia
5. Buccopharyngeal fascia
Common carotid a.
Internal jugular v.
Vagus n.
Retropharyngeal space
TRAPEZIUS
3. Prevertebral fascia

13. 2. Pretracheal layer
• It encloses and suspends the thyroid gland and
forms its false capsule.
• Posterior layer of the thyroid capsule is thick. On
either side it forms a suspensory ligament for
the thyroid gland known as LIGAMENT OF BERRY.
• The fascia provides a slippery surface for free
movements of the trachea during swallowing.

14. 3. Prevertebral layer
• It lies in front of the Prevertebral muscles.
• It forms the floor of the post. triangle
• Anterior layer/ alar fascia – blends with
Buccopharyngeal fascia
• Posterior layer – is attached to the anterior
longitudinal ligament.

15. 4. Carotid Sheath **
• It is a condensation of the fibroareolar tissue
around the main vessels of the neck.
• Anteriorly – by Pretracheal fascia
• Posteriorly – by Prevertebral fascia
• Contents are –
- common / internal carotid artery
- internal jugular vein
- vagus nerve (X)
• The upper part of sheath also contains IX, XI and
XII nerves
• The ansa cervicalis lies in the anterior wall of
the carotid sheath.

16. Carotid Sheath

17. 5. Buccopharyngeal fascia
• This fascia covers the superior constrictor muscle
externally and
• Extends on to the superficial aspect of the
buccinator muscle.

18. 6. Pharyngobasilar fascia
• It lies deep to the pharyngeal muscles.

19. Buccopharyngeal fascia
Prevertebral fascia
Retropharyngeal space
Base of skull
Mediastinum

20. Posterior Triangle

21. BOUNDARIES

22. posterior triangle
- Is a space on the side of the neck and situated
behind the SCM.
• Anteriorly – posterior border of SCM,
• Posteriorly – anterior border of trapezius
• Inferiorly/ base – by clavicle (middle 3rd)
• apex – on the superior nuchal line, where the
trapezius and SCM meet.

23. Roof
• Formed by the investing layer of deep cervical fascia.
• The superficial fascia over the posterior triangle contains-
1. Platysma
2. External jugular and post. External jugular veins
3. Parts of – supraclavicular
- great auricular
- transverse Cutaneous and
- lesser occipital nerves
4. Branches of – occipital,
- transverse cervical and
- supra scapular arteries
5. lymph vessels
• External jugular vein; lies deep to the platysma.
• It is formed by the union of post. Auricular vein with the post. division of retro
– mandibular vein. It opens into the subclavian vein.

24. ARTERIES IN POSTERIOR TRIANGLE
1 3

25. Retromandibular v.
Superficial temporal v. Maxillary v.
Facial v.
Common facial v.
(to IJV)
Posterior auricular v.
External jugular v.
Subclavian v.
EXTERNAL JUGUAR VEIN
Anterior jugular v.
Transverse cervical v.
Suprascapular v.

26. floor
• Formed by the Prevertebral layer of deep cervical
fascia, covering the following muscles-
1. Splenius capitis
2. Levator scapulae
3. Scalenus medius
4. Semispinalis capitis

27. Splenius capitis m.
Levator scapulae m.
Post., mid., & ant.
scalene mm.
Muscles of floor
MUSCLES OF FLOOR OF POSTERIOR TRIANGLE

28. Divisions of posterior triangle
• It is subdivided by the inferior belly of
omohyoid into:-
1. Large upper – occipital triangle
2. Small lower – subclavian / supra clavicular
triangle.

29. Contents of post triangle
1. Spinal accessory nerve
2. Four Cutaneous branches of cervical plexus-
a. Transverse Cutaneous
b. Supraclavicular
c. Great auricular
d. Lesser occipital
3. Muscular branches to the levator scapulae and to trapezius
4. Trunks of brachial plexus
5. Nerve to rhomboid
6. Nerve to serratus anterior
7. Nerve to subclavius
8. Suprascapular nerve / artery
9. Subclavian artery
10. Subclavian vein

30. Sternocleidomastoid muscle (SCM)
• SCM and trapezius are large superficial muscles of the neck.
• Both are supplied by the – spinal root of accessory nerve.
• Origin-
Sternal head – tendinous, arises from manubrium sterni
Clavicular head- musculoteninous, arises from medial one third of
the clavicle.
• Insertion- thick tendon on mastoid, and thin aponeurosis on
lateral half of superior nuchal line.
• Nerve supply - spinal root of accessory nerve (motor)
- branches from ventral rami of C2 (sensory)

31. .
Sterno cleido mastoid showing its
sternal haed and clavicular haed

32. Clinical anatomy
• Most common swelling in the post triangle is due to enlargement
of the supraclavicular lymph nodes.
• The Accessory Nerve may be damaged while taking lymph node
biopsy.
• The External Jugular Vein is present in a superficial location here
and this makes it vulnerable to injury
• Supraclavicular lymph nodes are commonly enlarged in TB,
Hodgkin’s disease and malignantant growth of breast, arm or
chest.
• Dysphagia caused by compression of the oesophagus by an
abnormal subclavian artery is called dysphagia lusoria.
• Torticollis is a deformity in which the head is bent to one side
and the chin points to the other side. This is due to spasm of
muscles supplied by the spinal accessory nerve, (SCM, Trapezius)

33. TORTICOLLIS