Prof. Saeed Abuel Makarem

1
Posterior triangle of the neck

• By
• Prof. Saeed Abuel Makarem

2
(No Transcript)
3
STERNOCLEIDOMASTOID

• The sternocleidomastoid or sternomastoid is a
  strap- like muscle that descends obliquely across
  the side of the neck.

4
TRIANGLES OF THE NECK

• The neck is divided into anterior and posterior
  triangles by the sternocleidomastoid muscle
• Anterior triangle lies in front of the muscle
• and
• Posterior triangle lies behind the muscle.

5

• Boundaries
• Anteriorly
• Posterior border of sternomastoid.
• Posteriorly
• Anterior border of Trapezius.
• Base
• Middle 1/3 of the clavicle.
• Apex
• meeting of Trapezius
• Sternomastoid.

6
OMOHYOID MUSCLE

• Omohyoid muscle has
• Inferior belly,
• Intermediate tendon,
• and
• Superior belly.

7

• The inferior belly of omohyoid subdivides the
  posterior triangle into
• a large occipital triangle above and
• a small supraclavicular triangle below.

8

• Roof
• Skin,
• Superficial fascia, which contains Platysma
  muscle
• Cutaneous branches of cervical plexus
• External jugular vein
• Investing layer of deep cervical fascia.
• Floor
• from below upward
• Scalenus medius,
• Levator scapulae,
• Splenius capitis, and
• Semispinalis capitis.
• The muscles of the floor are covered by
  prevertebral layer of deep cervical fascia.
• NB. Scalenus anterior is hidden by the
  sternomastoid muscle

9

• The deep fascia of the neck is called deep
  cervical fascia

• Parts of Deep Cervical Fascia
• Investing layer.
• Prevertebral layer.
• Pretracheal layer.
• Carotid sheath.

10
Investing Layer of Deep Cervical Fascia
11
(No Transcript)
12
PLATYSMA

• The platysma can be seen as a sheet of muscle by
  asking the patient to clench his jaw firmly.
• The muscle extends from the body of the mandible
  downward over the clavicle onto the anterior
  thoracic wall.

13

• Contents of Posterior triangle
• Nerves
• The main contents are nerves
• 1- The three trunks of the brachial plexus.
• 2- Four cutaneous branches of cervical plexus.
• (lesser occipital, great auricular, transverse
  cervical supraclavicular nerves.
• 3- Spinal accessory.
• Arteries
• 1- 3rd part of subclavian artery.
• 2- Suprascapular artery.
• 3- Transverse cervical artery.
• 4- Occipital artery.
• Veins
• 1- Subclavian vein.
• 2- External jugular vein.
• Muscle
• Inferior belly of omohyoid muscle.

14
ACCESSORY NERVE (SPINAL PART)11th cranial nerve

• The spinal part of the accessory nerve enters the
  posterior triangle by emerging from beneath the
  middle of the posterior border of sternomastoid
  muscle, which it has supplied.
• It runs downward and laterally across the
  posterior triangle on the levator scapulae
  muscle.
• It also supplies the trapezius.

15
EXTERNAL JUGULAR VEIN

• The external jugular vein begins just behind the
  angle of the mandible by the union of the
  posterior auricular vein the posterior
  division of the retromandibular vein.

16

• The external jugular vein descends obliquely
  superficial to sternomastoid muscle and, just
  above the clavicle in the posterior triangle,
  pierces the deep fascia and drains into the
  subclavian vein.
• It is the only tributary of the subclavian vein.
• It varies considerably in size, and its course
  extends from the angle of the mandible to the
  middle of the clavicle.

17
THIRD PART OF SUBCLAVIAN ARTERY

• The third part of the subclavian artery occupies
  the lower anterior angle of the posterior
  triangle just behind the sternomastoid muscle.

18
(No Transcript)
19
(No Transcript)