Tag: Anterior triangle of neck

Anterior triangle of neck

Anterior triangle of neck


ANTERIOR TRIANGLE OF NECK 

BOUNDARIES:

  • MEDIALLY: Anterior median plane of neck
  • LATERALLY: Sternocliedomastoid  muscles
  • SUPERIORLY:Base mandible & a line joining angle of mandible to mastoid process

SUBDIVISIONS:

It encloses :

  1. 4 suprahyoid muscles
  2. 4 infrahyoid muscles
  • It is divided into 4 subtriangles by  digastric & omohyoiid muscles:
SUBTRIANGLE BOUNDARIES CONTENTS
Submental
Sides Ant. belly of digastric
Base Body Of Hyoid
Apex At chin
Floor

Rt. & Lt. Mylohyoid muscle & median raphe uniting them

  1. 2 or 4 submental lymph node b/w ant. bellies of digastric
  2. Submental veins, Submental lymoh nodes
Digastric
 Anteroinferior Ant. belly of digastric
 Posteroinferior
  1. Post. belly of digastric
  2. Stylohyoid
 Superior or   base
  1.  Base mandible
  2. Line joining angle of mandible to mastoid process
 Roof
  1. Skin
  2. Superficial fascia: Platysma, Cervical branch of VII CN & ascending br. of transverse cutaneous
  3. Deep Fascia:Splits to enclose submandibular gland
 Floor
  1. Ant. Mylohyoid
  2. Post. Hyoglossus
  3. Middle constrictor
 Ant. Part Of   Triangle
  1. Structure sup. to Mylohyoid: Superficial part of Submandibular gland & lymph node, Facial Vein, facial artery, submental artery, mylohyoid nerve & vessels.
  2. Structure Sup. to hyoglossus: Sumandibular gland, Intermediate tendon of digastric,  stylohyoid, hypoglossal nerve
 Post. Part   Of Triangle
  1. Superficial :Lower part of parotid gland & ECA before entering parotid
  2. Deep:(b/w ex. & in. Carotid)Styloglossus, stylopharyngeus, glossopharyngeal nerve, Pharyngeal brannch of X CN, styloid process, part of parotid gland
  3. Deepest: Internal carotid , internal jugular, vagus
Carotid  

 Anterosuperior
  1. Post. Belly of digastric
  2. Stylohyoid
 Anteroinferior   Sup. belly of omohyoid
 Posterior   Ant. border of sternocliedomastoid
 Roof
  1. Skin
  2. Superficial fascia contain platysma, cervical branchVII, transverse cutaneous
  3. Investing layer of deep cervical fascia
 Floor
  1. Thyrohyoid muscle
  2. Hyoglossus
  3. Middle constrictor
  4. Inf. constrictor
 

 Arteries
  1. Common carotid artery , Carotid sinus, Carotid body
  2. Internal carotid artery
  3. External carotid artery with branches(sup. thyroid, lingual, facial,ascend. pharyngeal, facial
 Veins

Pharyngeal vein  Lingual vein

        ↓     X     ↓        

Common facial → Internal jugular

 Nerves
  1. Vagus→ sup. laryngeal→ext. & int. laryngeal
  2. Spinal accessory
  3. Hypoglossal→Upper root of ansa cervicalis & br. to thyrohyoid
  4. Sympathetic chain
 Lymph Node
  1. Deep cervical node
  2. Juglodigastric node
  3. Jugulo-omohyoid node
 Other

Carotid sheath & it’s content

Muscular  

 Anterior Ant. median line of neck from hyoid to  sternum
 Postersuperior Sup. belly of omohyoid
 Posteroinferior Ant. border of sternocleidomastoid
  • Infrahyoid muscles  arranged in 2 layers:
  1. Superficial:Sternohyoid, Omohyoid
  2. Deep:Sternothyroid, thyrohyoid
  • Ventral rami of 1, 2, 3 cervical spinal nerve
 
Exam Question
 
  • Anterior triangles of neck are-Submental, Digastric, Carotid, Muscular.
  • Submental lymph nodes drain superficial tissues beliw tge chin, central part of lower lip, adjoining gums, anterior part if floor of mouth & tip of tongue.
  • On both sides submental triangle is bounded by Anterior belly of diagastric.
  • Posterior boundary of carotid triangle is formed by anterior border of sternocleidomastoid.
  • Hypoglossal nerve is a content of both digastric & carotid triangles.
  • Structure superficial to mylohyoid in anterior digastric triangle is Mylohyoid artery & nerve
  • Floor of digastric triangle is formed by mylohyoid (anteriorly) & hyoglossus (posteriorly)
  • Infrahyoid ribbon muscles are the chief contents of muscular triangle.
Don’t Forget to Solve all the previous Year Question asked on Anterior triangle of neck

Anterior triangle of neck

ANTERIOR TRIANGLE OF NECK

Q. 1

All of the following are in the anterior triangle of neck EXCEPT:

 A

Diagastric

 B

Subclavian

 C

Muscular

 D

Submental

Q. 1

All of the following are in the anterior triangle of neck EXCEPT:

 A

Diagastric

 B

Subclavian

 C

Muscular

 D

Submental

Ans. B

Explanation:

  • Posterior triangle of neck has 2 parts: Occipital & subclavian
  • Subclavian triangle is also c/d as supraclavicular or omoclavicular triangle.
  • Anterior triangles of neck are-Submental, Digastric, Carotid, Muscular.

Q. 2

Structure superficial to mylohyoid in anterior digastric triangle are all EXCEPT:

 A

Deep part of submandibular gland

 B

Hypoglossal nerve

 C

Part of parotid gland

 D

Mylohyoid artery & nerve

Q. 2

Structure superficial to mylohyoid in anterior digastric triangle are all EXCEPT:

 A

Deep part of submandibular gland

 B

Hypoglossal nerve

 C

Part of parotid gland

 D

Mylohyoid artery & nerve

Ans. D

Explanation:

  • Deep part of submandibular gland & hypoglossal neve are deep to mylohyoid muscle.
  • Structures passing superficial to mylohyoid in anterior part of digastric triangle are submandibular gland (superficial part), facial vein, facial artery, mylohyoid nerve & vessels, hypoglossal nerve & submandibular nodes.

Q. 3

All is true about digastric triangle EXCEPT:

 A

On either side is anterior belly of digastric muscle

 B

Floor is formed by mylohyoid muscle

 C

Floor is formed by hyoglossus muscle

 D

Contains mylohyoid nerve & vessels

Q. 3

All is true about digastric triangle EXCEPT:

 A

On either side is anterior belly of digastric muscle

 B

Floor is formed by mylohyoid muscle

 C

Floor is formed by hyoglossus muscle

 D

Contains mylohyoid nerve & vessels

Ans. A

Explanation:

  • Digastric triangle is bounded by anterior belly if digastric anteriorly & posterior belly posteriorly.
  • Mylohyoid & hyoglossus muscles are the floor.
  • Digastric triangle contains mylohyoid nerve & vessels, submandibular gland, facial artery & vein, hypoglossal nerve & submandibular lymph nodes.

Q. 4

On both sides submental triangle is bounded by:

 A

Hyoid bone

 B

Anterior digastric 

 C

Posterior digastric

 D

Mylohyoid

Q. 4

On both sides submental triangle is bounded by:

 A

Hyoid bone

 B

Anterior digastric 

 C

Posterior digastric

 D

Mylohyoid

Ans. B

Explanation:

  • Submental triangle is bounded by anterior belly of digastric (laterally), midline of the neck b/w the mandible & the hyoid bone (medially) & base of hyoid bone.
  • Mylohyoid muscle is at the floor & submental lymph nodes are the content.


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