Download Triangles of neck

Triangles of neck
By
Dr. Adel Sahib Al-Mayaly
FICMS, FACS
The side of the neck
• It is quadrilateral outline
• Boundaries:• Above:- lower border of mandible and an
imaginary line extending from the angle of the
mandible to the mastoid process .
• Below:- by the upper border of the clavicle.
• In front:- the mid-line of the neck.
• Behind:- the anterior margin of the Trapezius
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Posterior Triangle and Its Subdivisions
• Boundaries:
• Anteriorly: posterior border of the SCM muscle.
Posteriorly: anterior border of the trapezius
muscle
• Inferiorly: intermediate one-third of the clavicle
• • Is subdivided into occipital and Subclavian
triangles by inferior belly of omohyoid m.
Subdivisions
• Subclavian (Omoclavicular) triangle.
• Ooccipital1-1-ccipital triangle.
Anterior triangle
Subdivisions of
anterior triangle
1-Submandibular triangle.
2- Submental triangle.
3-Carotid triangle.
4-Muscular triangle.
Carotid triangle
• Boundaries:
• Anteriorly: superior belly of the omohyoid
muscle
• Posteriorly: sternocleidomastoid muscle
• Superiorly: posterior belly of the digastric and
the stylohyoid muscles
• Floor: thyrohyoid, sternothyroid, and inferior
constrictor muscles
Contents
• the carotid arterial system, the internal jugular
vein with tributaries
• , the hypoglossal nerve, vagus nerve, the
superior laryngeal nerve, and the sympathetic
trunk.
Muscular triangle
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Superior belly of omohyoid above.
Anterior border of SCM muscle behind.
Midline of neck infront.
Floor: strap muscles:1- sternohyoid m.
2- sternothyroid m.
3- thyrohyoid m.
4- superior belly of omohyoid m.
Submandibular triangle
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Lower border of mandible above
Posterior belly digastric & stylohyoid behind .
Anterior belly of digastric infront
Floor:- the Mylohyoid, Hyoglossus, and superior
constrictor of pharynx.
• Contents :- submandibular g.& duct, submandibular
L.Ns.
Submental (suprahyoid) triangle
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Anterior belly of digastric on both sides.
Body of hyoid bone below.
Floor:- mylohyoid muscle.
Contents;- Submental lymph nodes
Muscles of anterior triangle
• 1- superficial muscles:- platysma, SCM &
trapezius.
• 2- Infrahyoid muscles.
• 3- Suprahyoid muscles.
• 4- lateral vertebral muscles (scalenae muscles).
Blood vessels of anterior triangle.
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• Carotid arterial system
Common carotid artery:Origin :Right side:- brachiocephalic trunk behind
sternoclavicular j.
Left side:- arch of aorta in the superior
mediastinum
Carotid arterial system
Common carotid artery
• On either side; it ascends upward within the
carotid sheath.
• At the level of upper border of thyroid
cartilage;
• It bifurcates into
• 1- Internal carotid artery.
• 2- External carotid artery.
Internal carotid artery
• It ascends upward within carotid sheath from
its origin.
• First; it is SF to ECA but then it becomes
behind & deep to ECA.
• At base of skull; it enters carotid canal to gain
access to cranial cavity.
• It gives no branches in the neck.
External carotid artery
• At first, it lies medial to the internal carotid
artery,
• As it ascends in the neck; it passes backward
and lateral to it.
• It is crossed by the posterior belly of the
digastric and the stylohyoid.
Branches of ECA
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Superior thyroid artery
Ascending pharyngeal artery
Lingual artery
Facial artery
Occipital artery
Posterior auricular artery
Superficial temporal artery
Maxillary artery
Internal jugular vein
• It emerges from jugular foramen at the base
of skull.
• It lies behind ICA at first ( at the base of skull).
• Here it receives the inferior petrosal sinus
• It descends in the carotid sheath lateral to the
ICA then CCA.
• At root of neck; it joins the subclavian vein to
form the brachiocephalic v.
Surface anatomy of IJV
Tributaries of IJV
Carotid sheath
• It extends from the base of skull (carotid canal)
to the arch of aorta.
• It encloses the carotid art., IJV & vagus nerve in
between.
• The sympathetic trunk is lying behind the sheath.
• The ansa cervicalis (C!,2,3) is embedded in its
ant. Wall.