Triangles Of The Neck: Anatomy, Borders And Contents

Triangles Of The Neck: Anatomy, Borders And Contents

Question 1. Describe the boundaries and contents of the Muscular Triangle
Answer.

Muscular Triangle Boundaries

Muscular Triangle Anteriorly: The anterior median line of the neck.

Muscular Triangle Posterosuperiorly: Superior belly of omohyoid.

Muscular Triangle Posteroinferiorly: Anterior border of the sternocleidomastoid.

Muscular Triangle Contents Infrahyoid (ribbon) muscles:

Question 2. Describe the boundaries and contents of the Submental Triangle
Answer.

Submental Triangle Boundaries

Submental Triangle Lateral (on each side): Anterior belly of digastric.

Submental Triangle Base: Body of hyoid bone.

Submental Triangle Apex: Symphysis menti.

Submental Triangle Floor: Oral diaphragm (formed by mylohyoid muscles).

Submental Triangle Roof: Investing layer of deep cervical fascia.

Submental Triangle Contents

• Submental lymph nodes (three to four in number)
• Submental veins, which unite to form anterior jugular veins

Anatomy Of Neck Triangles: Structures And Boundaries

Question 1. What are the subdivisions of the posterior triangle?
Answer.

The posterior triangle is divided into two parts by an inferior belly of omohyoid:

• A larger upper part is called the occipital triangle because it contains the occipital artery.
• A smaller lower part is called a subclavian triangle because it contains a subclavian artery. It is also called a supraclavicular triangle.

Question 2. Enumerate the structures piercing the roof of the posterior triangle.
Answer.

The roof of the posterior triangle is pierced by the following structures.

Four cutaneous nerves

• Lesser occipital nerve (C2)
• Great auricular nerve (C2 and C3)
• Transverse cervical nerve (C2 and C3)
• Supraclavicular nerves (anterior, middle and posterior; C3 and C4)

One vein External jugular vein

Anterior Triangle Of The Neck

 

From above to downward, these are

• Mylohyoid raphe (a fibrous raphe extending from the symphysis menti to the hyoid bone)
• Body of hyoid bone
• Median thyrohyoid ligament
• The angle of thyroid cartilage (Adam’s apple in males)
• Median cricothyroid ligament
• Cricoid cartilage
• The first ring of the trachea
• Isthmus of the thyroid gland lying on the 2nd, 3rd and 4th tracheal rings
• Infrahyoid veins and thyroid ima artery (sometimes)
• Jugular venous arch connecting two anterior jugular veins