Download Anterior triangle of neck

By
Dr. Adel Sahib Al-Mayaly
‫سنة مباركة عليكم وندعو هللا ان تكون سنة خير وامن وامان‬
‫على بلدنا واهلنا انه سميع الدعاء‬
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It emerges from the base of skull via the
jugular foramen.
It lies behind the ICA at the base of skull
It receives the inferior petrosal vein.
It descends lateral to the ICA & CCA then
anterolateral to the carotid artery during its
descent in the neck .
At the root of neck;
it joins the subclavian vein to form the
brachiocephalic vein .
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It leaves the cranial cavity through the jugular
foramen with cranial root of accessory n.
In the foramen the nerve is swollen to form
the superior ganglion.
A short distance below the foramen it bears
the larger inferior ganglion.
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Superior ganglion:- carries the cutaneous
neurons which travel through the auricular
nerve (Arnold nerve).
Inferior ganglion:- contains the taste &
visceral sensory neurons.
Below the inferior ganglion; is joined by
cranial root of accessory n.
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Vagus n. descends vertically down within the
carotid sheath first between ICA & IJV then
between the IJV & CCA.
In the root of neck;
•The right vagus nerve passes anterior to the
subclavian artery and posterior to the
sternoclavicular joint, entering the thorax.
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•The left vagus nerve passes inferiorly
between the left common carotid and left
subclavian arteries, posterior to the
sternoclavicular joint, entering the thorax.
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1- superior ganglion:A- meningeal branch:- to dura of post.
Cranial cavity.
B- auricular branch:- cutaneous n.
To external auditory canal
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2- inferior ganglion:A- pharyngeal branch:- it joins the
pharyngeal branch of GPN to form the
pharyngeal plexus.
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Pharyngeal plexus:- motor fibres from the
cranial root of accessory nerve to the muscles
of pharynx & soft palate.
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2- superior laryngeal nerve:It descends on the side of pharynx deep to
ICA
It divides
1-Internal laryngeal nerve:- it pierces the
thyrohyoid membrane to supply mucosa of
larynx above vocal cords.
2-External laryngeal nerve:- motor to inferior
constrictor & cricothyroid m.
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+3- Minute branches to the carotid body.
4- Recurrent laryngeal nerve:Right side:- neck by hooking around R
subclavian a.
It ascends in the neck in the groove between
the trachea & esophagus.
Left side:- stems from the vagus in front of
arch of aorta
It ascends in the neck to reach side of trachea
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Upon reaching the lower pole of thyroid lobe
the n. Is closely related to the inferior thyroid
artery.
The n. usually passes behind but infrequently
between or in front the recurrent laryngeal
nerve.
Superior & Inferior cardiac branches:- they
supply the parasympathetic of the heart
They join CARDIAC PLEXUS. They convey
parasympathetic fibres to the heart.
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Mylohyoid muscle
Hyoglossus muscle
Genniohyoid muscle
Digastric muscle
Stylohyoid muscle.
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Roof:- investing layer.
Floor:- Infrahyoid muscle.
Superior;-superior belly of omohyoid muscle.
Inferior;- anterior border of SCM
Anterior;- midline of neck.
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superior belly of omohyoid.
sternohyoid muscle.
thyrohyoid muscle.
sternothyroid muscle.
They are supplied by ansa cervicalis nerve
except thyrohyoid which supplied by C1via
hypoglossal n.
Muscle
Origin
Insertion
Innervation
sternohyoid Posterior surface
of manubrium
muscle
sterni
Medial part of
lower border of
hyoid bone
Ansa cervicalis
Sternothyroid Posterior surface
of manubrium
sterni
Oblique line of
thyroid cartilage
Ansa cervicalis
Thyrohyoid
Oblique line of
thyroid cartilage
Lower border of
the body and
the greater
cornu of the
hyoid bone
Cervical spinal
nerve 1 via the
hypoglossal
nerve
Omohyoid
(superior belly)
Intermediate
tendon
Hyoid bone
Superior root of
ansa cervicalis
(C1)
Omohyoid
(inferior belly
Superior border
of scapula
Intermediate
tendon
Ansa cervicalis
(C1-C3)
Muscle
Digastric (anterior
belly)
Digastric (
posterior belly)
Origin
Insertion
Digastric Intermediate
fossa of Tendon
Mandible
Innervation
Mylohyoid nerve branch of CN V3
(Mandibular division
of Trigeminal nerve
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4 muscles
1- sternohyoid muscle.
2- omohyoid muscle.
3- sternothyroid muscle.
4- thyrohyoid muscle.