Carotid triangle
Anatomy lec#14
Sunday
27-3/2011
Last lecture we talked about the anterior triangle & we said it is divided
into small sub triangles :
1- the submandibular triangle (Digastric ) .
2- the submental triangle.
3- the carotid triangle.
4- Muscular triangle.
Carotid triangle ( vascular triangle ) :
We name it the vascular triangle because it's contain a
large number of vessels .
Borders :
Posterior : sternocleidomastoid .
Superior : post. Belly of digastric muscle .
Anterior : sup. Belly of omohyoid .
Contents of carotid triangle :
1- Carotid sheath .
2- Common carotid artery .
3- External carotid artery .
4- Internal carotid artery.
5- Internal jugular vein.
6- Vagus nerve .
7- Hypoglossal nerve.
8- Sympathetic trunk.
9- Ansa cervicalis . ( ansak da klam )
10- Cervical lymph nodes.
Now we're going to talk about each content :
Carotid sheath : a- tubular extension of deep cervical fascia .
b- extending from the base of the skull to the
root of the neck at arch of aorta .(
c- contents : common carotid artery ( below).
external carotid artery (above) .
internal carotid artery ( above).
internal jugular v. ( most ) .
vagus nerve ( all way ) .
d- Sympathetic trunk lies behind the sheath .
(stick to the post. Part of the carotid sheath)
Common carotid artery :
Either right or left CCA :
Start behind sternocalavicular joint .
Ascend within carotid.
End sup. Border of thyroid cartilage by dividing into : 1 ICA( interior)
2-ECA(exterior)
External carotid artery : (8 branches)
1- Supplies structures outside the skull.
2- Pass deep to post belly of digastric (bridge) ; 5 below , 3 above
5 below: (Navy)
1- Superior thyroid (to the thyroid ) .
2- Ascending pharyngeal (to the pharynx).
3- Lingual (to the tongue).
4- Facial. (to the face).
5- Occipital.( occipital bone).
3 above : (air force)
1- Post. Auricular artery.
2- Superficial temporal.
3- Maxillary.
3-Start at the upper border of thyroid cartilage.
4- Ascend within the carotid sheath .
5- End within parotid (behind neck of the mandible) by dividing into ;
1- Superficial temporal A.
2- Maxillary artery.
Internal carotid artery :
Start upper part of thyroid cartilage .
Ascend inside carotid sheath .
Passing within the carotid triangle
End at the base of the skull , where ?? by entering the carotid canal
which continue as foramen lacerum.
Has 4 parts : 1- cervical.
2- petrous .
3- cavernous.( inside the cavernous sinus , S shape)
4- cerebral ,gives :
a- ant. Cerebral artery.
b- middle cerebral A.
every artery Has a vein with the same name but reverse direction & at
the end all of these veins will drain into IJV .
Internal jugular Vein : direct continuation of sigmoid sinus
Begins: in jugular foramen as a continuation of sigmoid sinus .
Descend: within carotid sheath .
End: at root of the neck by uniting with subclavian vein to form The
Brachiocephalic vein.(in the right & left ).
Has : Bicuspid valve at its end (inferior bulb) But In general ijv is
valvless .
Drains : brain, face, neck.
Hypoglossal nerve :
Descend : Deep to digastric post. To enter carotid triangle .
Ascend : Deep to digastric post. To enter digastric triangle
Pass between mylohyoid and hyoglossus muscles .
Exit : via hypoglossal canal .
Motor to all tounge muscles except on ( palato glossus )
Carry C1 nerve . (geniohyoid)
Anas cervicalis : (ansa=loop)
Loop of nerves from C1-C3 to supply muscles in the ant.
Triangle.has 2 roots :
1- Sup. C1 nerve join CN xii after leaving the skull.
2- inf. From c2,c3 nerves of cervical plexus completing the
loop that form ant. To Internal jugular vein.
Vagus nerve: The 10th cranial nerve.
Leave The skull via jugular foramen.
Pass throughout the carotid sheath between , Internal
carotid + (CCA & Internal jugular vein). All through the
carotid sheath.
Rt recurrent laryngeal n. loop below right subclaviar.(muscle
of the larynx).
Lt recurrent laryngeal n. loop below aortic arch. (between
esophagus &trachea )
Cranial root of CN xi join vagus below inferior ganglia
..distributed in pharyngeal & recurrent laryngeal branches.
Done by : Raghad al-farajat :D