Structures In Anterior Median Region Of Neck Question And Answers

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Structures In Anterior Median Region Of Neck Question And Answers

Question 1. Write short note on structures in anterior median region of neck.
Answer:

Structures in anterior median region of neck

  • The region extends from chin to sternum
  • Structures from superficial to deep include:
    • Skin: Freely movable over deeper structures
    • Superficial fascia consisting of:
      • Upper decussating fibers of platysma
      • Anterior jugular vein just above the hyoid bone
      • Submental lymph nodes below the chin
      • The transverse cutaneous nerve of neck.
    • Deep fascia
      • Above the hyoid bone, it is single-layered in the median plane but in sides, it splits to enclose the submandibular gland
      • Between the hyoid bone and cricoid cartilage, it is a single layer
      • Below the cricoid cartilage, it splits and encloses suprasternal space.
  • Deeper structures can be studied under the following heading
    • Lying above the hyoid bone
      • Mylohyoid muscle
      • Anterior belly of digastric and its tendon
      • Mylohyoid nerve and its vessel
      • Submental branch of facial artery
      • Anterior inferior part of hyoglossus muscle
      • Stylohyoid muscle
      • Subhyoid bursa.

Lying below the hyoid bone structures are grouped into 3 planes.

  • Superficial Plane
    • Infrahyoid muscles
      • Sternohyoid
      • Sternothyroid
      • Thyrohyoid
      • Superior belly of omohyoid
  • Middle Plane
    • pretracheal fascia
    • Thyrohyoid membrane
    • Thyroid cartilage
    • Thyroid gland
    • Cricothyroid membrane
    • Cricoid cartilage
    • Cricothyroid muscle
  • Deep Plane
    • Larynx
    • Trachea
    • Associated structures

Anterior Median Region Of Applied

  • Skin incisions in the neck are made parallel to natural creases/Langer’s line so that they heal easily and will not be visible.
  • Cutthroat wound are commonly present just above or below the hyoid bone and the great vessels are usually spared since the voluntary extension of neck causes these vessels to be pushed backward to a deeper plane.
  • Tracheostomy is the process in which the trachea is opened a tube in inserted for ventilation it is usually done in the retro thyroid region after retracting the isthmus of the thyroid gland.

Question 2. Write a note on the anterior triangle of neck.
Answer:

The anterior triangle of neck

Structures In Anterior Median Region Of Neck Lateral View Of The Neck Depicting Boundaries Of Triangles Of Neck

It is a triangular space on each side of the anterior midline of neck in front of the sternocleidomastoid

Anterior Triangle Of Neck Boundaries:

  • Anterior: The anterior median line of the neck from symphysismenti to the suprasternal notch
  • Posterior: Anterior border of sternocleidomastoid
  • Apex: Suprasternal notch where anterior border of the sternocleidomastoid and anterior median line meets
  • Base: Lower border of body of the mandible and the imaginary line joining angle of mandible to the mastoid process
  • Roof: Investing layer of deep cervical fascia

For descriptive purposes, the anterior triangle has been subdivided by digastric muscle and superior belly of omohyoid into:

  • Submental triangle
  • Digastric/submandibular triangle
  • Carotid triangle
  • Muscular triangle.
  • The digastric muscle has two bellies, the posterior and anterior belly—the posterior belly arises from the mastoid process and runs towards the hyoid bone whereas the anterior belly arises from base of the mandible near the symphysismenti which again runs towards the hyoid bone.
  • And just above the bone, both bellies are connected by a tendon which is anchored to the hyoid bone.

Submental Triangle: Median triangle, which is unpaired, and half of it lies on each side of the midline of neck.

Submental Triangle Boundaries:

  • Apex: Lies at chin
  • Base: Formed by body of the hyoid bone
  • Laterally: Anterior belly of digastric muscles on each side
  • Floor: Right and left mylohyoid muscles

Submental Triangle Contents:

  • 2–4 small submental lymph nodes in the superficial fascia between anterior bellies of digastric muscles.
  • They drain superficial tissues of the chin, lower lip, gums and anterior portion of floor of mouth, and tip of tongue and drain into the submandibular lymph node
  • Small submental veins joins and form anterior jugular veins.

Digastric Triangle Or Submandibular Triangle: Boundaries of digastric triangle

  • Anteroinferiorly: Anterior belly of digastric
  • Posteroinferiorly: Posterior belly of digastric and stylohyoid
  • Base: Base of the mandible and line joining the angle of the mandible to the mastoid process
  • Apex: Intermediate tendon of digastric which is attached to hyoid bone
  • Floor:
    • Mylohyoid muscle anteriorly
    • Hyoglossus muscle, small part of middle constrictor muscle posteriorly
  • Roof: Investing layer of deep cervical fascia which encloses submandibular gland superficial fascia above it, consisting of Platysma, cervical branches of the facial nerve

The triangle is divided into anterior and posterior parts by the stylomandibular ligament which arises from tip of the styloid process and attaches to angle of mandible.

Digastric Triangle Or Submandibular Triangle Contents:

  • Contents in anterior part of the triangle.
    • Submandibular gland
    • Submandibular lymph node
    • Facial artery
    • Facial vein
    • Hypoglossal nerve
    • Mylohyoid nerve and vessels
    • Submental artery.

Digastric Triangle Or Submandibular TriangleTip: Digastric triangle is in the submandibular region of face where arteries are deep and veins superficial with nerves to flor muscles

  • Contents in posterior part of triangle
    • External carotid artery
    • Carotid sheath and its contents
    • Styloid process
    • Styloglossus and stylopharyngeus muscle
    • Glossopharyngeal nerve.
  • Contents include external carotid arteries and structures that pass between external and internal carotid artery.

Carotid Triangle: Boundaries of Carotid Triangle

  • Superiorly: Posterior belly of digastric and stylohyoid
  • Anteroinferiorly: Superior belly of omohyoid
  • Posteriorly: Anterior border of sternocleidomastoid muscle
  • Roof: Investing layer of deep cervical fascia, superficial tissues, and its contents
  • Floor: Formed by 4 muscles
    • Thyrohyoid
    • Hyoglossus
    • Middle and inferior constrictor.

Carotid Triangle Contents:

  • Common carotid artery and its branches
  • Carotid sinus and its body
  • Internal jugular vein
  • Last 3 cranial nerves vagus, spinal accessory, and hypoglossal nerves
  • Ansa cervicalis and cervical sympathetic chain
  • Deep cervical lymph nodes.

Muscular Triangle: Boundaries Of Muscular Triangle

  • Anterior: Anterior median line of neck
  • Anterosuperior: Superior belly of omohyoid
  • Posteroinferiorly: Anterior border of sternocleidomastoid
  • Floor: Sternothyroid, sternohyoid muscle
  • Roof: investing layer of deep cervical fascia, superficial fascia

Muscular Triangle Contents:

  • Infrahyoid muscles (ribbon muscles):
    • Superficial
      • Sternohyoid
      • Omohyoid
    • Deep
      • Sternothyroid
      • Throhyoid
  • Supplied by ventral rami of 1, 2, and 3 cervical spinal nerves and are involved in the movement of hyoid bone and thyroid cartilage.

Anterior Triangle Of Neck Applied

  • The submandibular triangle is a common site of swellings due to the presence of submandibular lymph nodes and submandibular salivary gland.
  • The carotid sinus may be hypersensitive in some persons and in such cases, the sudden rotation of head causes the slowing down of the heart known as carotid sinus syndrome.
  • In cases of supraventricular tachycardia, carotid sinus massage can be done to control heart rate due to the inhibitory effects of vagus nerve on the heart.

Structures In Anterior Median Region Of Neck Multiple Choice Question And Answers

Question 1. The subclavian artery is divided into 3 parts:

  1. Scalenus posterior muscle
  2. Scalenus medius muscle
  3. Scalenus anterior muscle
  4. Scalenus minimus muscle

Answer: 3. Scalenus anterior muscle

Question 2. All of the following arises from the thyrocervical trunk except:

  1. Inferior thyroid artery
  2. Suprascapular artery
  3. Superficial cervical artery
  4. Dorsal scapular artery

Answer: 3. Superficial cervical artery

Question 3. The cervical part of the facial artery gives all of the following branches:

  1. Inferior alveolar artery
  2. Tonsillar artery
  3. Glandular branches to submandibular gland
  4. Submental artery

Answer: 1. Inferior alveolar artery

Question 4. The cerebral part of the internal carotid artery gives all of the following branches:

  1. Anterior cerebral artery
  2. Posterior communicating artery
  3. Posterior choroidal artery
  4. Middle cerebral artery

Answer: 3. Posterior choroidal artery

Question 5. All of the arteries arise from first part of the subclavian artery except:

  1. Throcervical trunk
  2. Dorsal scapular artery
  3. Internal mammary artery
  4. Vertebral artery.

Answer: 2. Dorsal scapular artery

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