Topographic Anatomy

2.  OVERVIEW;
The Ant. Region of the Neck is Divides into:
 Medial T.
 Lateral T.
 SCM R.
 SUBDIVISION:
I. Medial
II. Lateral
Carotid
Submandibular
Submental
Scapulotracheal
(Omotracheal)
Omotrapezius (occipital)
Supraclavicular
Infrahyoid R.
Suprahyoid R.
By the body of
Hyoid bone
By Inf. Belly of
Omohyoid muscle

3. Suprahyoid region:
• Boundaries: Inf. border of the mandible, Sup.
Ant. border of SCM muscle, Lat.
Line drown by the Hyoid bone, Inf.
• Coverings: Skin, Superficial fascia, 2nd
fascia,
Sheath ,formed by 2nd
fascia, gives
two layers attached to the inf. border
of the Mandible.
• Floor: Mylohyoid and Hyoglossus muscles.
Submental triangle
• Boundaries: Chin, Sup.
Body of the hyoid bone, Inf.
Ant. Bellies if both digastric muscle, Lat.
• Contents: Submental lymph node + beginning of AJV.

4. Submandibular triangle
•Boundaries: Inf. Border of the Mandible, Sup.
Both bellies of Digastric muscle,
Ant. & Post.
•Contents: The gland, The lymph, fat, fascial A&V
•Structures:
•Hypoglossal NHypoglossal N.. runs on hyoglossus muscle deep to the gland.
•Lingual ALingual A.. ,from ECA, enters deep to the Post. border of Hyoglossus muscle.
Maybe found for ligation in Pirgoff’s triangle.

5. Infrahyoid region:
•Boundaries: Sternal notch, Inf.
Ant. Border of SCM muscle, Lat.
Line of the body of Hyoid bone, Sup.
•Coverings: Skin, Subcutaneous tissue, Platysma,
Proper fascia (superficial, deep,
parietal, visceral) & the Infrahyoid Ms.
•Contents: Branches of transverse cutaneous N.
•Floor: Sternohyoid and sternothyroid muscles.
Contents: Organs of the neck (Thyroid gland, Trachea, Larynx, Pharynx & Esophagus).
Omotracheal triangle:
• Boundaries: Medline of the Neck, Ant.
Ant. Border of SCM muscle, Inf.
Sup. Belly of Digastric muscle, Sup.

6. Carotid triangle
•Boundaries: Post. Belly of Digastric muscle, Sup.
Sup. Belly of Omohyoid muscle, Inf.
Ant. Border of SCM muscle, Post.
•Coverings: Skin, Fascia, Carotid sheath,
Proper Fascia(Superficial), Platysma.
•Contents: Carotid sheath (CCA+E,I CAs+IJV)
Int+Ext. Laryngeal, Hypoglossal & descending branch,
Accessory & Vagus Nerves.
•Structures:
CCA lies medial & deep to IJV.
Left CCA comes from arch of Aorta.
Right CCA is one of the terminal branches of right Brachiocephalic A.
CCA gives NONO branches.

7. Structures:
 Descending branch of hypoglossal N. and Ansa Cervicalis embedded in the
wall of Carotid sheath.
 Organs of Neck + Inf. Thyroid A. + recurrent laryngeal N. lie MedialMedial To CCA.
 Scalenus Ant. muscle + sympathetic trunk + prevertebral region lie LateralLateral .
 CCA lie opposite to Ant. Tubercle of C6 transverse process.
 ECA lies Anteromedial to ICA.
 Branches of ECA (Sup. Thyroid, Lingual, Fascial, Occipital, Ascending
Pharyngeal, Post. Auricular, Maxillary, Superficial Temporal) .
 ICA has no branches, It enters the base of the skull through Carotid Canal
Pharynx lies medial to it.
 IJV drains from Brain, Neck and Face and enters Jagular foramen and Carotid
sheath. Units with Subclavian V. to form Brachiocephalic V.
 Vagus N. enters the Carotid sheath vertically and lie between IJV & ICA then
between IJV & CCA. (meningeal, auricular, pharyngeal, sup.&recurrent laryngeal, cardiac)
 Right recurrent Laryngeal N. hooks around 1st
part of Subclavian A.
 Left recurrent Laryngeal N. hooks around Arch of the Aorta.

8. Lateral triangle:
•Boundaries: Clavicle, Inf.
Post. Border of SCM muscle, Ant.
Ant. Border of Trapezius muscle, Post.
Omotrapezius triangle
•Boundaries: SCM muscle, Ant.
Trapezius muscle, Post.
Inf. Belly of Omohyoid muscle, Inf.
Fascias of the Neck:Fascias of the Neck: 11stst
, 2, 2ndnd
, 5, 5thth
..
Supraclavicular triangle
•Boundaries: Clavicle, Inf.
SCM muscle, Med.
Inf. Belly of Omohyoid muscle, Sup.
Fascias of the Neck:Fascias of the Neck: 11stst
, 2, 2ndnd
, 3, 3rdrd
, 5, 5thth
..

9. Supraclavicular triangle
Structures:
Subclavian V. lies Ant. & Inf. to the Clavicle.
Subclavian A. lies Post. & Sup. To the Clavicle.
Brachial plexus lies Post. To the Clavicle.
Right Subclavian A. arises from Brachiocephalic A.
Left Subclavian A. arises from arch of Aorta.
Scalenus Ant. Passes Ant. To the A. and divides
it into three parts:
11stst
part:part: Subclavian A. Med. border of the muscle.
Branches: Thyrocervical trunk + int. thoracic A.
22ndnd
part:part: Behind the muscle.
Branches: Costocervical trunk Sup. Intercostal A. 1st
& 2nd
ICSs.
33rdrd
part:part: Lat. Border of the muscle Post. Triangle Lat. Border of 1st
rib.
No branches. Axillary A.
Deep cervical A. deep Ms. of Neck.