Side Of The Neck Question And Answers

Question 1. Describe the boundaries & contents of Subclavian Triangle
Answer:

Boundaries of Subclavian Triangle:

Anteriorly: Posterior border of sternocleidomastoid

Posteriorly: Inferior belly of omohyoid

Inferiorly base: Middle 1/3 of clavicle

Apex: Lies where inferior belly of omohyoid crosses sternocleidomastoid

Roof: Investing layer of deep cervical fascia

Read And Learn More: BDS Previous Examination Question And Answers

Floor: Scalenus medius.

Subclavian Triangle Contents:

1. Subclavian Triangle Contents Nerves:

• Three trunks of branchial plexus
  • Subclavian Triangle emerges between the scalenus anterior & medius
  • Subclavian Triangle carries axillary sheath along with it which contains branchial plexus & subclavian artery
• Nerve to serratus anterior
  • Subclavian Triangle arises by roots of C5, C6, C7
  • The nerve passes behind the branchial plexus & descends over the serratus anterior
• Nerve to subclavius
  • Subclavian Triangle descends in front of branchial plexus & subclavian vessels
  • Subclavian Triangle sometimes give off the accessory phrenic nerve which joins the phrenic nerve in front of the scalenus anterior
• Suprascapular nerve
  • Subclavian Triangle arises from the upper trunk of the branchial plexus & crosses the lower part of the posterior triangle
  • Subclavian Triangle supplies the supraspinatus & infraspinatus muscles

2. Subclavian Triangle Contents Vessels:

• Third part of subclavian artery & subclavian vein
  • The subclavian artery passes behind the tendon of the scalenus anterior
  • Subclavian vein passes in front of the tendon
• Suprascapular artery & vein
  • Suprascapular artery is a branch of the thyrocervical trunk
• Commencement of transverse cervical artery & termination of the corresponding vein. It is a branch of the thyrocervical trunk
  • Subclavian Triangle crosses

1. 1. 1. Scalenus anterior
      2. Phrenic nerve
      3. Upper trunks of the branchial plexus
      4. The nerve to the subclavius
      5. Suprascapular nerve
      6. Scalenus medius

• • It divides into superficial & deep branches
• Lower part of external jugular vein
  • Subclavian Triangle lies deep to the platysma
  • Subclavian Triangle is formed by union of the posterior auricular vein & posterior division of retromandibular vein
  • Subclavian Triangle opens into the subclavian vein

3. Subclavian Triangle Contents  Lymph Nodes:

• A few members of the supraclavicular chain
• Posteroinferior group of deep cervical lymph node

Subclavian Triangle Contents Applied Anatomy:

• Enlargement of inferior group of deep cervical lymph nodes on left occurs in malignant growth of stomach
• Superficial incision to open subcutaneous abscess may injure the accessory nerve
• Any external injury may cause damage to upper trunk of branchial plexus
• This results in Erb’s palsy

Question 2. Formation of external jugular vein
Answer:

By union of the posterior auricular vein & posterior division of retromandibular vein

Question 3. Contents of carotid sheath
Answer:

• Common carotid arteries
• Internal carotid artery
• Internal jugular vein
• Vagus nerve