Neck

Question 1

What are the muscles of the infrahyoid?

Answer 1

Question 2

What are the boundaries of the posterior triangle?

Answer 2

Anterior wall- sternocleidomastoid

Posterior wall- trapezius

Inferior wall- clavicle

Floor- Splenius capitus, Levator scapulae, The Anterior, Middle and PosteriorScalenes

Roof- cervical investing fascia

Question 3

What are the contents of the subclavicular triangle and where is it located?

Answer 3

located inferior to the omohyoid. It contains the distal portion of the subclavian artery

• The brachial plexus and subclavian artery enters the triangle between the anterior and middle scalene muscles
• The subclavian vein enters the triangle between the anterior scalene muscle andsternocleidomastoid
• The phrenic nerve runs vertically down the anterior aspect of the anterior scalene muscle

Question 4

What are the contents of the occipital triangle and where is it located?

Answer 4

located superior to the omohyoid.

• The occipital triangle only contains one key structure – the accessory nerve (CN XI). It enters the triangle through the substance of sternocleidomastoid and disappears deep to trapezius.

Question 5

What are the nerves in the posterior triangle?

Answer 5

• Theaccessory nerve (CNXI)exits the cranial cavity, descends down the neck, innervates sternocleidomastoid and enters the posterior triangle. It crosses the posteriortrianglein an oblique, inferoposterior direction, within theinvestinglayer of fascia. It lies relatively superficialin the posterior triangle, leaving it vulnerable to injury.
• Thecervical plexusforms within the muscles of thefloorof the posterior triangle. A major branch of this plexus is thephrenic nerve, which arises from the anterior divisions of spinal nerves C3-C5. It descends down the neck, within theprevertebralfascia, to innervate the diaphragm. Other branches of the cervical plexus innervate the vertebral muscles, and provide cutaneous innervation to parts of the neck and scalp.
• The trunks of thebrachial plexusalso cross the floor of the posterior triangle.

Question 6

What is the vasculature in the posterior triangle?

Answer 6

• Theexternal jugular veinis one of the major veins of the neck region. Formed by the retromandibular and posterior auricular veins, it lies superficially, entering the posterior triangle after crossing the sternocleidomastoid muscle. Within the posterior triangle, the external jugular vein pierces the investing layer of fascia and empties into the subclavian vein.
• Thesubclavian veinis often used as a point of access to the venous system, via a central catheter. The transverse cervical and suprascapular veins also lie in the posteriortriangle.
• The subclavian, transverse cervical and suprascapular veins are accompanied by their respective arteries in the posterior triangle. The distal part of thesubclavian arterycan be located as it emerges between the anterior and middlescalenemuscles. As it crosses the first rib, it becomes theaxillaryartery, which goes onto supply the upper limb.

Question 7

What are the borders of the anterior triangle?

Answer 7

• Superiorly– inferior border of the mandible (jawbone).
• Laterally– anterior border of the sternocleidomastoid.
• Medially– sagittal line down the midline of the neck.
• Roof- Investing fascia
• Floor-visceral fascia

Question 8

What is in the carotid sheath?

Answer 8

Medial- common carotid artery
Lateral- internal jugular vein
Posterior- vagus nerve

Question 9

What is the neurovasculature and lymphatics of the thyroid?

Answer 9

Question 10

What is the course of the right and left recurrent laryngeal nerves?

Answer 10

The right and left recurrent laryngeal nerves are visible as they originate in (the right recurrent laryngeal nerve), or pass through (the left recurrent laryngeal nerve), the root of the neck.

• The right recurrent laryngeal nerve is a branch of the right vagus nerve [X] as it reaches the lower edge of the first part of the subclavian artery in the root of the neck. It passes around the subclavian artery and upward and medially in a groove between the trachea and the esophagus as it heads to the larynx.
• The left recurrent laryngeal nerve is a branch of the left vagus nerve [X] as it crosses the arch of the aorta in the superior mediastinum. It passes below and behind the arch of the aorta and ascends beside the trachea to the larynx.
• Damage may lead to hoarse voice or inability to speak

Question 11

What is the origin of the left and right common carotid arteries?

Answer 11

• The right common carotid artery originates from the brachiocephalic trunk immediately posterior to the right sternoclavicular joint and is entirely in the neck throughout its course.
• The left common carotid artery begins in the thorax as a direct branch of the arch of the aorta and passes superiorly to enter the neck near the left sternoclavicular joint.

Question 12

What are the branches of the external carotid artery?

Answer 12

• Some- Superior thyroid artery - first branch
• Anatomists- Ascending pharyngeal artery - second and smallest branch
• Like- Lingual artery arises from the anterior surface of the external carotid artery
• Freaking- facial artery is the third branch of the external carotid artery (arises just above the lingual artery)
• Out- Occipital artery arises from the posterior surface of the external carotid artery
• Poor- Posterior auricular artery is a small branch arising from the posterior surface
• Medical- Maxillary artery is the larger of the two terminal branches of the external carotid artery
• Students- Superficial temporal artery is one of the terminal branches and appears as an upward continuation of the external carotid artery

Question 13

What forms the external jugular vein?

Answer 13

Retromandibular vein
Posterior auricular vein

Question 14

What is the laryngeal innervation and vasculature?

Answer 14

Recurrent laryngeal nerve (branch of vagus nerve)
– motor to all intrinsic muscles except cricothyroid
– sensory below vocal folds
Superior laryngeal nerve (branch of vagus nerve)
• internal laryngeal nerve (sensory above vocal folds)
• external laryngeal nerves (motor to cricothyroid)

Arteries
• Branches of superior & inferior thyroid artery

Veins
• To internal jugular vein or left brachiocephalic vei