Infrahyoid Neck

Question 1

The what muscle divides the anterior and posterior triangles of the neck?

Answer 1

Sterniocleidomastoid muscle

Question 2

The infrahyoid anterior triangle is subdivided by what muscle into muscular and carotid triangles?

Answer 2

Superior belly of the omohyoid muscle

Question 3

What are the boundaries of the muscular triangle?

Answer 3

Superior = Superior belly of omohyoid muscle

Inferolateral = Sternocleidomastoid muscle

Midline = No medial boundary; these paramedian triangles meet in midline

Question 4

What are the contents of the muscular triangle?

Answer 4

Infrahyoid strap muscle
Hypopharynx and larynx 
Cervical trachea and esophagus
Thyroid and parathyroid glands
Recurrent laryngeal nerve (vagus nerve branch)

Question 5

What are the boundaries of the carotid triangle?

Answer 5

Inferior = Superior belly of omohyoid muscle

Lateral = Sternocleidomastoid muscle

Superior = Posterior belly of digastric muscle

Question 6

What are the contents of the carotid triangle?

Answer 6

Common carotid artery
Internal jugular vein
Vague nerve 
Cervical sympathetic trunk
Lymph nodes (deep cervical or internal jugular chain)

Question 7

The posterolateral cervical neck is subdivided by what muscle into the occipital and subclavian triangles?

Answer 7

Inferior belly of the omohyoid muscle

Question 8

What are the boundaries of the occipital triangle?

Answer 8

Anteromedial = Sternocleidomastoid muscle

Posterolateral = Trapezius muscle

Inferior = Inferior belly of the omohyoid muscle

Question 9

What are the contents of the occipital triangle?

Answer 9

Fat
Spinal accessory nerve
Dorsal scapular nerves
Transverse cervical veins and arteries
Lymph nodes (spinal accessory chain)

Question 10

The muscular triangle occupies the area called ________.

Answer 10

Visceral space

Question 11

The carotid triangle occupies the area called the _______.

Answer 11

Carotid space

Question 12

What are the boundaries of the subclavian triangles?

Answer 12

Superior = inferior belly of omohyoid muscle

Anteromedial = Sternocleidomastoid muscle

Posterolateral = Trapezius muscle

Question 13

What are the contents of the subclavian triangle?

Answer 13

Third portion of subclavian artery
Transverse cervical artery and vein
Cervical portion of brachial plexus

Question 14

Three layers of deep cervical fascia cleave the infrahyoid neck into fascia fascia-defined spaces.

What are these layers?

Answer 14

Superficial (investing) layer
Middle (visceral) layer
Deep (prevertebral) layer

These facial names are the same as in the suprahyoid neck, with the exception of the middle layer of deep cervical fascia, called the buccopharyngeal fascia in the suprahyoid neck.

Question 15

What are the five major spaces identified in the infrahyoid neck?

Answer 15

Visceral space
Carotid space
Posterior cervical space
Retropharyngeal space
Perivertebral space

Question 16

Of the five spaces, only what space is unique to the infrahyoid neck?

Answer 16

Visceral space

The carotid, posterior cervical, retropharyngeal, and perivertebral space all traverse both suprahyoid and infrahyoid.

Question 17

What are the contents of the posterior cervical space?

Answer 17

Fat
Spinal accessory nerve (cranial nerv XI)
Spinal accessory lymph node chain
Preaxillary brachial plexus 
Dorsal scapular nerve

Question 18

The posterior cervical space extends to where?

Answer 18

From a small superior tip at the skull base to the clavicle

Question 19

The extent of the retropharyngeal space.

Answer 19

Skull base to level of T3 vertebral body

Question 20

The danger space can be found where?

Answer 20

Found directly behind the retropharyngeal space

Question 21

The anterior and posterior area of the perivertebral space are referred to as what?

Answer 21

The anterior area = prevertebral portion of the perivertebral space

The posterior area = paraspinal portion of the perivertebral space

Question 22

What are the contents of the prevertebral portion of the perivertebral space?

Answer 22

Prevertebral muscles, longus coli muscle
Scalene muscles (anterior, middle, posterior)
Proximal brachial plexus 
Phrenic nerve 
Vertebral artery and vein
Vertebrae and pedicles

Question 23

What are the contents of the paraspinal portion of the perivertebral space?

Answer 23

Paraspinal muscles

Posterior vertebral body elements (including lamina and spinous process)

Question 24

The extent of the perivertebral space.

Answer 24

Skull base to mediastinum at approximately the T3 level