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To MBBS 2nd yearDr. Laxman Khanal
Assistant professor, department of Anatomy, BPKIHSDate:07-02-2017
Anterior Triangles of
Neck
Q. Which side of SCM muscle is in action ?a. Rightb. Leftc. Both
Q. Identify the muscle.
SternoCleido
Mastoid
Compartments of neck region
1. Visceral 2. Vertebral3. Neurovascular
Cut throat wounds normally escape the injury to vesselsbecause they become pushed back in deeper plane involuntary extension of neck.
Subcutaneous structures of neck
•Triangular gap betweenthe two heads of SCMis called lessersupraclavicularfossa.•It contains the terminalpart of the IJV, which canbe entered at this site by aneedle or catheter.
Nerve supplySpinal accessory nerve Branch from C2 and C3
Function of right SCM• Same side lateral flexion• Opposite head rotation
Function of Bilateral SCM
Anterior triangle of neck
Division of anterior triangle
1.Digastric triangle2.Carotid triangle3.Muscular triangle4.Submental triangle
Fascial sling (investing layer)
Roof
Floor
Room
Investing layer of deep cervical fascia
Muscles
1. Submental2. Digastric3. Muscular4. Carotid
• What forms the walls?• Who resides in the room?
+Bones (H +M)Midline of neck
Contents
Submental triangle•Boundaries•Floor •Contents-Submental LN -Submental vein-Ant jugular vein
Triangle mostly occupied by lymph node.
Boundaries Contents-Infrahyoid muscles1. Sternohyod and
Omohyoid2. Sternothyroid and
Thyrodyoid- Thyroid gland- Trachea- Esophagus
Muscular triangleWith no named vessels.
Attachment of infra-hyoid musclesOmo-Hyoid/Sterno-HyoidThyro-Hyoid/Sterno-Thyroid
# TOSS
• All except T are supplied by Ansa Cervicalis (C1 to C3).
• T supplied by C1 through hypoglossal nerve.
Ansa Cervicalis lies in carotid trianglebut supplies muscular triangle.
Suprahyoid muscles1. Geniohyoid2. Mylohyoid3. Digastric4. Stylohyoid
Location-digastric and submental (suprahyoid region).
Muscle of anterior neckSuprahyoid-submental and digastric Infrahyoid- muscular
Carotid triangleBoundariesFloor-Middle constrictor-Thyrohyoid membrane-Inferior constrictorContents
CCAICA &ECAfive branches of ECA
Vagus nerveSup laryngeal branch
Spinal accessory nerveHypoglossal nerveIJVCommon facial veinLingual veinAscending pharyngeal veinCCA, IJV, 10 /11 /12 CN
ContentsCCAICAECALower five branchesVagus nerveSup laryngeal branchSpinal accessory nerveHypoglossal nerveIJVCommon facial veinLingual veinAscending pharyngeal vein
1. Carotid sheath2. External CA3. 11th CN4. 12th CN
Artery- Carotid systemVein- IJVNerve- 10/11/12 nerve
1. Ascending pharyngeal artery2. Sup thyroid artery3. Lingual artery4. Facial artery5. Occipital artery6. Posterior auricular artery7. Maxillary artery8. Superficial temporal artery
Ext carotid artery
Sup belly of omohyoid
Post belly of digastic
SCM
1. Anterior2. Posterior3. Medial4. Terminal
Carotid sinus Syndrome
NTS
Sudden rotation of headTight collar
IXth CNXth CN
• Decrease BP• Bradycardia• Vasodilation
Pressure
Sympathetic
Heart Vessels
Rare cause of Syncope or sudden death
Artery- Carotid systemVein- IJVNerve- 10/11/12 nerve
T O S S
Digastric triangleBoundariesFloor-Mylohyoid-Hyoglosus-Midle constrictorContentsAnterior part1. Superficial to mylohyoid2. Superficial to hyoglossusPosterior parts
ContentsAnterior part1. Superficial to mylohyoid2. Superficial to hyoglossusPosterior parts
Imp QnsWhat are the strs superficial to mylohyoid ?What are the strs superficial to hyoglossus ?
Posterior part of Digastric triangle
Lower part of parotidECAICAIJVVagus nerve
Superficial to mylohyoid1. Superficial part of submandibular gland
(facial artery and vein)1. Submental artery2. Mylohyoid Nerve3. Mylohyoid vessels
Relationship of Hyoglossusmuscle
• Deep part of SM gland• Duct of SM gland• SM ganglion• Lingual nerve• Hypoglossal nerve• Vena comitantes
• Stylohyoid ligament• IX th nerve• Lingual artery
Superficial to Hyoglossus• Deep part of submandibular gland • Submandibular duct• Hypoglossal and Lingual nerve• Submandimular ganglion• Styloglossus muscle
?????
• Anterior neck contains two groups of muscles.
1. Supra hyoid
2. Infra hyoid
• Carotid system, IJV and CN (X, XI & XII) pass through carotid triangle.
• Ansa cervicalis lies anterior to carotid sheath and supplies infrahyoid muscles except Thyrohyoid.