Lecture 1: Neck: Superficial Triangles and Cervical Viscera

Question 1

What triangles is the Platysma m. part of and what is it innervated by?

Answer 1

• Forms part of roof of the anterior and posterior triangles
• Innervated by: Cervical branch of the Facial n (VII)

Question 2

What forms the borders, roof, and floor of the Posterior (lateral) triangle of the neck?

Answer 2

• Middle 1/3 of clavicle
• Trapezius
• SCM
• Roof = platysma and investing fascia
• Floor = prevertebral fascia

Question 3

What is the action and innervation of the SCM?

Answer 3

Action:

Unilateral contraction = flexes and rotates the head

Bilateral = flex the head

Innervation:

Spinal accessory nerve (XI)

Question 4

Conjunction of which veins form the EJV and where does this vein drain?

Answer 4

• Conjunction of: posterior auricular and retromandibular veins
• Drains into: subclavian vein

Question 5

The spinal accessory nerve (XI) receives contributions from; innervating what muscles?

Answer 5

C2-3 for SCM

C3-4 for Trapezius

Question 6

Where is Erb’s Point and what is found here?

Answer 6

• Posterior edge of the mid-point of the SCM
• C5-6 nerve roots of brachial plexus
• The 4 superficial cervical nerves
• Spinal accessory (XI) is located about 1cm above Erb’s point

Question 7

Penetrating injuries to Erb’s point may lead to?

Answer 7

• Erb’s palsy (“waiters tips”)
• XI palsy
• Anesthesia of the skin of the neck or upper chest/shoulders

Question 8

What is a Hangman’s fracture?

Answer 8

The fracture affects the vertebra called the axis, the second cervical vertebra (C2), with or without subluxation (slippage) of C2 on the third cervical vertebra (C3).

Question 9

What important vein and nerve are found anterior to the anterior scalene muscle; what is the relationship of these vessels to one another?

Answer 9

• Subclavian vein
• Phrenic nerve

* The subclavian v. is immediately deep to the clavicle and just deep to the subclavian v. is the phrenic n. sitting on top of the anterior scalene muscle - the nerve is pressed between the vein and muscle

Question 10

What is found posterior to the anterior scalene muscle in the interscalene triangle?

Answer 10

• Subclavian artery
• Brachial plexus (C5-T1)

Question 11

What is the principle anatomical structure and nerve involved in Muscular Torticollis and what is the most frequent cause?

Answer 11

• Most frequently caused by birth trauma
• Benign fibrous tumor may accompany this condition and is known as “Fibromatosis Colli”
• A hematoma may occur and entrap branch of spinal accessory nerve (CN XI) denervating part of the SCM

Question 12

What makes up the borders of the Carotid Triangle?

Answer 12

• Posterior Digastric
• Superior Omohyoid
• SCM

Question 13

What important vascular and nervous structures are found within the Carotid Triangle?

Answer 13

• Branches of carotid system
• IJV + Tributaries
• Ansa Cervicalis
• CN IX, X, and XII

Question 14

What makes up the borders of the Submandibular Triangle?

Answer 14

• Inferior edge of the mandible
• Anterior and Posterior Digastric M.
• Hyoid bone forms apex of the triangle

Question 15

What are the 5 suprahyoid muscles?

Answer 15

1) Digastrics (Anterior and Posterior)
2) Stylohyoid
3) Mylohyoid
4) Geniohyoid
5) Hyoglossus

Question 16

Innervation of the Anterior Digastric, Posterior Digastric, Stylohyoid, Mylohyoid, Geniohyoid, and Hypoglossus ms.?

Answer 16

Anterior = Mylohyoid n.

Posterior = VII

Stylohyoid = VII

Mylohyoid = Mylohyoid n. (V3)

Geniohyoid = C1

Hypoglossus = XII

Question 17

The submandibular gland occupies most of which triangle?

Answer 17

Posterior portion of the Submandibular Triangle

Question 18

Which glands can be/are affected by epidemic parotitis (mumps)?

Answer 18

• Submandibular Salivary Gland
• Parotid Gland

Question 19

The Submandibular Salivary Gland is drained by; describe the course of the structure that drains it and where it finally empties.

Answer 19

• Drained by the submandibular duct (Wharton’s duct)
• This duct courses antero-medially along the lateral surface of the hypoglossus then the genioglossus
• Submandibular duct empties into the floor of the mouth at the apex of the sublingual caruncle adjacent to the lingual frenulum

Question 20

Which nerve spirals around the submandibular (Wharton’s duct)?

Answer 20

Lingual nerve spirals around in a supero-lateral to infero-medial direction

Question 21

What artery supplies the submandibular gland and where does lymph from this gland drain?

Answer 21

• Facial artery
• Lymph drains to deep cervical nodes via submandibular nodes

Question 22

Describe the PARASYMPATHETIC innervation of the Submandibular and Sublingual Salivary Glands, including both the pre and post-ganglionic fibers routes.

Answer 22

• Preganglionic fibers from the superior salivatory nucleus exit the brainstem w/ the facial nerve, travel thru chorda tympania, and join w/ the lingual nerve before terminating in the submandibular ganglion
• Postganglionic fibers from submandibular ganglion distribute as numerous short branches to the parenchyma of the gland

Question 23

Where do the postganglionic SYMPATHETIC fibers innervating the Submandibular Sailvary Gland originate and how to they reach the gland?

Answer 23

• Originate in the superior cervical ganglion
• Reach the gland by coursing in the external carotid and facial plexuses in the adventitia of the respective arteries

Question 24

What are the contents of the Submandibular Triangle?

Answer 24

1) Submandibular ganglion
2) Lingual nerve
3) Hypoglossal (XII) nerve
4) Glossopharyngeal (IX) nerve
5) Lingual artery and vein

Question 25

What cervical levels is zone 1 for penetrating neck trauma and what structures are at risk for injury?

Answer 25

- C5-C6 - Root of neck, **Lower Parasagittal Region**, - Proximal Common Carotid, Vertebral and Subclavian arteries, Trachea, Esophagus, Thoracic Duct, Thymus Brachial Plexus, Superior mediastinum

Question 26

What cervical levels is zone 2 for penetrating neck trauma and what structures are at risk for injury?

Answer 26

- C3-C4 - Carotid and Submandibular Triangles, **Middle and Upper Parasagittal Regions** - Internal/External Carotid Arteries, Jugular Veins, Pharynx, Larynx, Esophagus, Recurrent Laryngeal n, Spinal Cord, Trachea, Thyroid, and Parathyroids

Question 27

What cervical levels is zone 3 for penetrating neck trauma and what structures are at risk for injury?

Answer 27

- C1-C2 - Carotid and Submandibular Triangles, Retromandibular Region, **Upper Parasagittal Region** - Distal Extracranial Carotid and Vertebral arteries + Uppermost segment of the Jugular Veins

Question 28

What is the relationship of the recurrent laryngeal nerve to the thyroid gland; what does it innervate?

Answer 28

- Located medial to the lobes between the trachea and esophagus - Innervates **ALL** the muscles of the larynx, **except** the cricothyroid

Question 29

Describe the blood supply to the thyroid gland; where do these 3 arteries arise from?

Answer 29

- **Superior thyroid artery** arises from the common or external carotids - **Inferior thyroid artery** arises from the thyrocervical trunk - **Lowest thyroid artery** may arise from the brachiocephalic, aorta, or left common carotid

Question 30

What 3 veins drain the thyroid gland and where do they drain into?

Answer 30

- **Superior** and **middle thyroid veins** drain into **IJV** - **Inferior thyroid vein** drains into the brachiocephalic vein.

Question 31

What vertebral levels does the trachea start and end at?

Answer 31

C6-T2

Question 32

What is a tracheotomy vs. cricothyrotomy?

Answer 32

**Tracheotomy** = emergency airway that is cut through **tracheal rings 2-4**, but has generally been replaced by... **Cricothyrotomy** = establishes an emergency airway by cutting through the **cricothyroid membrane**

Question 33

What are the boundaries and clinical significance of the retropharyngeal space?

Answer 33

- Bounded by the **B****uccopharyngeal fascia Anteriorly**and the**P****revertebral fascia Posteriorly** - Infections may spread from the neck to the thorax (or vice versa) through the retropharyngeal space - Surgically the **anterolateral approach** is **most** common and this space is commonly utilized for **fusion** of cervical vertebra of **C5 and C6**

Question 34

What are the structures involved in thoracic outlet syndrome (TOS): neurogenic, venous and arterial. What are the symptoms?

Answer 34

- Space between clavicle and first rib containing: brachial plexus, subclavian A and V. **Neurogenic**: numbness of limb, pain, weakness **Vascular**: weak pulse, blood clots, and pallor/coldness **Causes:** poor posture and repetitive use

Question 35

What is the anatomical structure/relationship to the trachea of the thyroid gland?

Answer 35

- **2 lobes** adjacent to the trachea - Usually connected by an **isthmus**, which overlies tracheal rings 2-4

Question 36

What is a Thyroid Ima Artery and the clinical consequences of the presence of a thyroid ima artery?

Answer 36

- 10% of people have small unpaired thyroid ima artery branch of the **brachiocephalic a.** - Other sources may be: **arch of the aorta, right common carotid, subclavian, or internal thoracic as.** - Presence of this artery **must be considered** before **tracheotomy** (as a potential source of bleeding!)

Question 37

What is the clinical significance of a subclavian venous puncture and what is the route?

Answer 37

- Often the point of entry to the venous system for **central line placement**, such as **pulmonary artery catheter** - Needle punctures skin inferior to thumn (center of clavicle) and advances medially toward the tip of the index finger until entering right venous angle, posterior to the sternoclavicular joint

Question 38

What is an aberrant thyroid gland and its clinical significance to a thyroglossal cyst?

Answer 38

- Thyroid glandular tissue found along the path of the embryonic thyroglossal duct - Sometimes associated w/ a thyroglossal cyst, so is important to differentiate between glandular tissue and a cyst when planning to excise a cyst. Failure to do so may result in a **total thyroidectomy,** leaving a person permanently dependent on thyoid medication

Question 39

Clinical significance of being able to locate the common carotid artery; absensce of carotic pulse is indication of?

Answer 39

- Checking the carotid pulse; done routinely during **CPR**; absence of carotid pulse indicates **cardiac arrest** - Lies in a groove between the trachea and the infrahyoid muscles - Usually palpated just deep to the anterior border of the SCM at level of the superior border of the thyroid cartilage.

Question 40

Postganglionic sympathetic fibers originating from the superior cervical ganglion reach the sublingual gland how?

Answer 40

Course through the external carotid plexus, facial plexus, or SUBLINGUAL PLEXUS on the **sublingual branch** of the **lingual artery**