Neck Anatomy

Question 1

What are the boundaries of the neck?

Answer 1

Inferiorly: Thoracic Inlet (1st thoracic vertebrae, 1st Rib and Costal Cartilage, Manubrium)
Superiorly: Inferior border of the mandible, angle of mandible, mastoid process, external occipital protuberance, superior nuchal line

Question 2

What are the important anatomical features of the neck? (5)

Answer 2

1. Hyoid Bone - C3 vertebrae
2. Thyroid Cartilage - C4 upper border
   - bifurcation of CCA; chemoreceptors and baroreceptors here
3. Cricoid Cartilage - C6
   - superior end of esophagus and trachea
4. Trachea
5. Jugular Notch

Question 3

What are the boundaries of the anterior and posterior triangle of the neck?

Answer 3

Anterior Triangle: Midline of the Neck, Anterior Border of SCM, Inferior border of Mandible

Posterior Triangle: Posterior Border of the SCM, Middle 1/3 of Clavicle, Anterior Border of Trapezius

Question 4

Tell me about the fascia of the neck.

Answer 4

Superficial Cervical Fascia
- Contains blood and lymphatic vessels, lymph nodes and fat, and the platysma

Deep Cervical Fascia
- Investing Fascia
- Pre-Tracheal Fascia
– Located behind the investing fascia, in front of the strap muscles, to enclose the thyroid gland
– fuses with the carotid sheath laterally
– fused with the prevertebral fascia
- Pre-vertebral fascia
– Encloses pre-vertebral muscles
– Lymph nodes of the posterior triangle are superficial to it
– Extends as the axillary sheath to enclose the axillary artery, vein and brachial plexus

Question 5

Why does the thyroid gland move with swallowing?

Answer 5

Thyroid is attached to the cartilage of the larynx by the suspensory ligament of berry

Question 6

Branches of the facial nerve?

Answer 6

1. Frontal
2. Zygomatic
3. Buccal
4. Marginal Mandibular
5. Cervical

Question 7

Muscles of Neck

Answer 7

1

Question 8

Where is the carotid sheath located in the neck?

Answer 8

Posterior to the SCM; anteromedially to the anterior scalene

Question 9

What are the contents of the carotid sheath?

Answer 9

Common Carotid Artery and its bifurcation; Internal Jugular Vein and Vagus Nerve

Question 10

What are the branches of the external carotid artery?

Answer 10

Some Attendings Like Freaking Out Potential Medical Students

Superior Thyroid Artery
Ascending Pharyngeal Artery
Lingual Artery
Facial Artery
Occipital Artery
Posterior Auricular Artery
Maxillary Artery
Superficial Temporal Artery

Question 11

Name the anastomoses and collateral circulation relating to the thyroid

Answer 11

Left and Right Superficial Temporal Arteries
Left and Right Superior Thyroid Arteries
Left and Right Inferior Thyroid Arteries
Left and Right Facial Arteries
Superior and Inferior Thyroid Arteries

Question 12

Describe the vein flow in the neck

Answer 12

Posterior Auricular Vein and Superficial Temporal Vein unite to form External Jugular Vein

Superficial Temporal Vein also has a branch to unite with the facial vein that unites to become the common facial vein. Facial vein drains into the internal jugular vein

EJV and IJV drain into subclavian vein then into the brachiocephalic vein to SVC

Question 13

Surface mark the EJV

Answer 13

Angle of Mandible to Midpoint of Clavicle

Question 14

What are the branches of the subclavian artery?

Answer 14

Part 1:
- Vertebral
- Thyrocervical Trunk –> Inferior Thyroid
- IMA

Question 15

What are the contents of the anterior triangle and posterior triangle of the neck?

Question 16

What is the main nervous plexus of the neck. Tell me about it.

Answer 16

Cervical Plexus.

‘Motor Branches’
- Phrenic Nerve (C3-C5): Anterior to Ant scalene, to enter thorax, descends anterior to root of the lung to reach the diaphragm
- C1 nerves that innervate the thyrohyoid and geniohyoid flowing within the hypoglossal
- Ansa Cervicalis
- Minor Branches (C3-C4: Levator Scapulae, Trapezius and Middle Scalene)

‘Sensory’ Branches - Let’s Go To Sleep
- Lesser Occipital
- Greater Auricular
- Transverse Cervical
- Supraclavicular

Question 17

What is the course of spinal accessory nerve?

Answer 17

C1-C6 nerev roots coalese, run superiorly to enter the cranial cavity via foramen magnum

Traverses posterior cranial fossa to reach the jugular foramen, exits skull with CN9 and CN10

Descrnds along the ICA to reach SCM, moves across the posterior triangle of the neck to the trapezius

Question 18

Tell me about the sympathetic trunk in the neck

Answer 18

Three cervical ganglia
- Superior (C2-C3): Sympathetic innervation mostly from here
- Middle (C6)
- Inferior (First rib behind vertebral artery)

Embedded on the posterior wall of the carotid sheath

Question 19

Where is the location of the thyroid gland

Answer 19

C5 to T1, below cricoid cartilage

Question 20

What is the blood supply of the thyroid gland?

Answer 20

Superior Thyroid Artery (ECA)
Inferior Thyroid Artery (Subclavian –> Thyrocervical Trunk –> IFA)

Question 21

What is the importance of the cricothyroid muscle. What is its nerve supply?

Answer 21

Tenses the vocal cord for screaming. Supplied by the External Laryngeal Nerve

Question 22

Tell me about the nerve supply around the thyroid gland?

Answer 22

Vagus nerve runs in carotid sheath. On left side, gives off a recurrent laryngeal branch that curves under arch of aorta . On right side, gives off recurrent laryngeal branch that curves under subclavian artery. These are in close proximity to the Inferior Thyroid Artery. Eventually the nerve lies just deep to the isthmus.

Vagus nerve also gives off the superior laryngeal nerve which branches into the internal and extenal laryngeal branches. External is in close proximity to the superior thyroid artery. Internal pierces the thyrohyoid membrane