Triangles of the Neck

Question 1

Boundaries of the Neck

Answer 1

Superior – Lower border of mandible
Inferior – Clavicle
Anterior – Anterior midline of neck
Posterior – Trapezius

Question 2

Bounded by:

Ant border of SCM
Anterior midline of neck
Inferior border of the mandible

Answer 2

ANTERIOR TRIANGLE

Submental
Submandibular
Carotid
Muscular

Question 3

The anterior triangle is subdivided into 4 smaller triangles by

Answer 3

Digastric and Omohyoid muscles

Question 4

Apex: symphysis menti
On each side: Ant. Belly of digastric m.
Base: body of the Hyoid bone
Floor – Mylohyoid

Answer 4

Submental Triangle

Question 5

Ant. and Post. Bellies of Digastric m.

Inferior border of mandible
Floor - Mylohyoid

CONTENTS

submandibular gland (salivary)
submandibular lymph	 nodes

The facial artery and vein also pass through this area

Answer 5

Digastric/Submandibular Triangle

Question 6

Superior belly of omohyoid
Posterior belly of digastric
Ant. border of SCM

CONTENTS

common carotid artery (which bifurcates within the carotid triangle into the external and internal carotid arteries)

internal jugular vein
hypoglossal and vagus nerves

Answer 6

Carotid Triangle

Question 7

Superior belly of omohyoid
Ant. midline of the neck
Ant. border of SCM

CONTENTS

infrahyoid muscles
pharynx
thyroid
parathyroid glands

Answer 7

Muscular Triangle

Question 8

dilation of the proximal part of the INTERNAL CAROTID BODY

innervated by the glossopharyngeal nerve (CN IX) through the carotid sinus nerve as well as by the vagus nerve (CN X)

baroreceptor (pressoreceptor) - reacts to changes in arterial blood pressure

Answer 8

CAROTID SINUS

Question 9

Small, reddish brown ovoid mass of tissue that lies in a septum on the medial (deep) side of the BIFURCATION of the common carotid artery in close relation to the carotid sinus

chemoreceptor - monitors the level of oxygen in the blood

stimulated by low levels of oxygen and initiates a reflex that increases the rate and depth of respiration, cardiac rate, and blood pressure

supplied mainly by the carotid sinus nerve (CN IX) and by CN X

Answer 9

CAROTID BODY

Question 10

Bounded by:

Post border of SCM
Anterior border of trapezius
Superior border of clavicle

Answer 10

POSTERIOR TRIANGLE

Occipital Triangle
Supraclavicular Triangle/ Subclavian/Omoclavicular

Question 11

Contents of the Posterior Triangle

Answer 11

Nerves: The main contents are nerves:
the three trunks of the brachial plexus

four cutaneous branches of the cervical plexus
o lesser occipital n.
o great auricular n.
o transverse cervical n.
o supraclavicular n.

spinal accessory n

Arteries:
• 3rd part of the subclavian a.
• Suprascapular a.
• Transverse cervical a.
• Occipital a.

Veins:
• Subclavian v.
• External jugular v.

Muscle: Inferior belly of omohyoid m.