Triangles & Root Of The Neck - Pt 2 - Quiz, Flashcards & Trivia

1. A metastatic lung cancer patient presents with recent-onset anhidrosis, miosis, and ptosis on the left side. He also has pain in his left arm. His oncologist is worried about this because it likely represents disease progression as indicated by tumor compression of which of the following?

Right sympathetic trunk

Left sympathetic trunk

Right CN X

Left CN X

Left CN XI

This is a description of Horner syndrome, which can occur with compression of the ipsilateral sympathetic trunk by a tumor on the apex of the lung, causing patient presentation of a parasympathetically-dominant set of symptoms as well as, possibly, ipsilateral arm pain. Option A would cause right-sided Horner syndrome. Compression of any of the other nerve choices would not cause a set of symptoms as presented in the question stem.

Explanation

This is a description of Horner syndrome, which can occur with compression of the ipsilateral sympathetic trunk by a tumor on the apex of the lung, causing patient presentation of a parasympathetically-dominant set of symptoms as well as, possibly, ipsilateral arm pain. Option A would cause right-sided Horner syndrome. Compression of any of the other nerve choices would not cause a set of symptoms as presented in the question stem.

2. A 26-year old man is involved in an accident and presents to your clinic afterwards for a check-up. You believe he may have a lesion in the posterior triangle of his neck, specifically the spinal accessory nerve. How would you test this nerve?

Test for sensations over his face

Elicit the gag reflex

Examine for the power of his muscles of mastication

Examine for his sense of smell, using ground coffee, for example

Ask the patient to shrug his shoulder and to turn his head against resistance

the spinal accessory nerve innervates the trapezius and sternocleidomastoid muscles. Asking the patient to shrug his shoulder and turn his head against resistance would test the actions of both of these muscles.

Explanation

the spinal accessory nerve innervates the trapezius and sternocleidomastoid muscles. Asking the patient to shrug his shoulder and turn his head against resistance would test the actions of both of these muscles.

3. A 46 year old male came into the clinic a few days after having surgery in the root of the neck and claimed it was hard for him to breath. The doctor investigated and found that the diaphragm is not contracting on the side he had surgery. The nerve that is damaged has what nerve roots?

C2-C4

C3-C5

C4-C6

C1-C3

C5-C6

The nerve that is damaged is the phrenic nerve, which can be found in this area. The nerve roots are C3, C4, C5.

Explanation

The nerve that is damaged is the phrenic nerve, which can be found in this area. The nerve roots are C3, C4, C5.

4. A lesion to the chorda tympani nerve would result in what deficit?

Loss of taste and pain/temp sensation to anterior 2/3 of tongue

Loss of taste to posterior 1/3 of tongue

Loss of taste to anterior 2/3 of tongue and parasympathetic activity to submandibular/sublingual glands

Loss of pain/temp sensation to anterior 2/3 of tongue and parasympathetic activity to submandibular/sublingual glands

Loss of taste and motor activity to anterior 2/3 of tongue

The chorda tympani (CN VII) carries taste sensation to anterior 2/3 of tongue and parasympathetic activity to submandibular/sublingual glands via the lingual nerve. The pain/temp/touch sensation to the anterior 2/3 of tongue is carried by mandibular division of trigeminal nerve (CN V3) via lingual nerve. Taste and pain/temp/touch sensation to the posterior 1/3 of the tongue is carried by the glossopharyngeal nerve (CN IX). All motor sensation to the tongue is done by they hypoglossal nerve (CN XII).

Explanation

The chorda tympani (CN VII) carries taste sensation to anterior 2/3 of tongue and parasympathetic activity to submandibular/sublingual glands via the lingual nerve. The pain/temp/touch sensation to the anterior 2/3 of tongue is carried by mandibular division of trigeminal nerve (CN V3) via lingual nerve. Taste and pain/temp/touch sensation to the posterior 1/3 of the tongue is carried by the glossopharyngeal nerve (CN IX). All motor sensation to the tongue is done by they hypoglossal nerve (CN XII).

5. You remove a mass in the posterior triangle of a patient. During a post-op visit the patient complains she is having trouble brushing her hair. During a neurological exam you notice drooping of the right shoulder. Lesion to what structure in the posterior triangle could have been compromised from the surgery?

Spinal accessory nerve

Suprascapular nerve

Ansa cervicalis

Hypoglossal nerve

Vagus nerve

The spinal accessory nerve lies in the posterior triangle, and can be easily damaged in posterior triangle neck surgeries. The spinal accessory nerve innervates the Trapezius muscle, which if denervated would result in drooping of the shoulder and weakness in abduction of the arm. (b) is located in the posterior triangle, however, this nerve innervates the supraspinatus and denervation of this structure is not consistent with the patient’s presentations. Damage to this structure would present with weakness in abduction (first 15 degrees), but drooping of the shoulder would not be prominent. (c) and (e) are located in the carotid sheath which is not located in the posterior triangle. Also lesions to these structures are not consistent with the patient’s presentation. (d) the hypoglossal nerve is not located in the posterior triangle, and damage to this structure would result in weakness to the tongue muscles.

Explanation

The spinal accessory nerve lies in the posterior triangle, and can be easily damaged in posterior triangle neck surgeries. The spinal accessory nerve innervates the Trapezius muscle, which if denervated would result in drooping of the shoulder and weakness in abduction of the arm. (b) is located in the posterior triangle, however, this nerve innervates the supraspinatus and denervation of this structure is not consistent with the patient’s presentations. Damage to this structure would present with weakness in abduction (first 15 degrees), but drooping of the shoulder would not be prominent. (c) and (e) are located in the carotid sheath which is not located in the posterior triangle. Also lesions to these structures are not consistent with the patient’s presentation. (d) the hypoglossal nerve is not located in the posterior triangle, and damage to this structure would result in weakness to the tongue muscles.

6. You've started working out a lot since coming to the island because you want to impress your friends and family back home. You even start working out muscles you never have in the past, such as your scalenes. However, recently you've felt some tingling in your fingers when you laterally flex your neck to the same side. Which structure could be causing this problem?

Phrenic Nerve

Subclavian Artery

Ansa Cervicalis

Brachial plexus

Brachial plexus runs through the anterior and middle scalenes hypertrophy of these muscles can cause irritation to these nerves.

Explanation

Brachial plexus runs through the anterior and middle scalenes hypertrophy of these muscles can cause irritation to these nerves.

7. A metastatic lung cancer patient presents with recent-onset anhidrosis, miosis, and ptosis on the left side. He also has pain in his left arm. His oncologist is worried about this because it likely represents disease progression as indicated by tumor compression of which of the following?

Right sympathetic trunk

Left sympathetic trunk

Right CN X

Left CN X

Left CN XI

This is a description of Horner syndrome, which can occur with compression of the ipsilateral sympathetic trunk by a tumor on the apex of the lung, causing patient presentation of a parasympathetically-dominant set of symptoms as well as, possibly, ipsilateral arm pain. Option A would cause right-sided Horner syndrome. Compression of any of the other nerve choices would not cause a set of symptoms as presented in the question stem.

Explanation

This is a description of Horner syndrome, which can occur with compression of the ipsilateral sympathetic trunk by a tumor on the apex of the lung, causing patient presentation of a parasympathetically-dominant set of symptoms as well as, possibly, ipsilateral arm pain. Option A would cause right-sided Horner syndrome. Compression of any of the other nerve choices would not cause a set of symptoms as presented in the question stem.

8. A 25-year-old medical student presents to the Health Clinic with a lesion on the inferior medial vermillion (lip) border consistent with Staphylococcus aureus bacterial infection. Upon examination, the physician finds enlarged lymph nodes. To which of the following groups of lymph nodes is this infection likely to drain first?

Submandibular lymph nodes

Submental lymph nodes

Deep cervical lymph nodes

Retropharyngeal lymph nodes

Occipital lymph nodes

The submental lymph nodes receive primary drainage from the lower lip and floor of mouth. Submandibular lymph nodes drain the buccal area, the lateral aspects of the nose, the lateral aspect of the lower lip, the upper lip, the gums, and the anterior tongue. They also receive some drainage from the submental lymph nodes, but are not the primary site of spread from the lower lip. The deep cervical lymph nodes receive afferents from the submandibular and submental lymph nodes, but it would not be the first site of enlargement. The retropharyngeal lymph nodes drain the nasopharynx, the nasal cavity, and the Eustachian tube. The occipital lymph nodes drain the occipital area of the scalp.

Explanation

The submental lymph nodes receive primary drainage from the lower lip and floor of mouth. Submandibular lymph nodes drain the buccal area, the lateral aspects of the nose, the lateral aspect of the lower lip, the upper lip, the gums, and the anterior tongue. They also receive some drainage from the submental lymph nodes, but are not the primary site of spread from the lower lip. The deep cervical lymph nodes receive afferents from the submandibular and submental lymph nodes, but it would not be the first site of enlargement. The retropharyngeal lymph nodes drain the nasopharynx, the nasal cavity, and the Eustachian tube. The occipital lymph nodes drain the occipital area of the scalp.

9. A patient presents to the ER with a stab injury to the neck. You determine that the stab wound is quite large and is found posterior to the sternocleidomastoid, superior to the clavicle and anterior to the trapezius. Which motor nerve is at highest risk of damage?

Lesser occipital nerve

Vagus nerve

Hypoglossal nerve

Facial nerve

Transverse cervical nerve

Spinal accessory nerve

The region described in the stem refers to the posterior triangle, which contains the external jugular vein, cervical plexus and cranial nerve XI (spinal accessory). Answers A and E are incorrect because they are sensory nerves, whereas the question asked for a motor nerve. Answers B, C and D are not found in the posterior triangle and are incorrect. Additional information: if the phrenic nerve had been listed as an option, it would have had an equal possibility of being damage since it is also found in the posterior triangle.

Explanation

The region described in the stem refers to the posterior triangle, which contains the external jugular vein, cervical plexus and cranial nerve XI (spinal accessory). Answers A and E are incorrect because they are sensory nerves, whereas the question asked for a motor nerve. Answers B, C and D are not found in the posterior triangle and are incorrect. Additional information: if the phrenic nerve had been listed as an option, it would have had an equal possibility of being damage since it is also found in the posterior triangle.

10. A patient has an infection at the tip of his tongue after a strangely placed tongue ring; which of the following triangles of the neck contain the lymph node that would primarily receive the lymph drainage from the affected area?

Suboccipital Triangle

Muscular Triangle

Carotid Triangle

Submandibular Triangle

Submental Triangle

remember the lymph drainage from the tip of the tongue is to the submental lymph nodes. The submental lymph nodes are found in the corresponding submental triangle (which is an unpaired midline triangle).

Explanation

remember the lymph drainage from the tip of the tongue is to the submental lymph nodes. The submental lymph nodes are found in the corresponding submental triangle (which is an unpaired midline triangle).

11. A patient comes in to the ER with a superficial incision mid way through the anterior triangle of the neck. What cutaneous nerve and nerve root is most likely to be damaged?

Supraclavicular n. (C3, C4)

Transverse cervical n. (C2, C3)

Greater Auricular n. (C2, C3)

Transverse anterior n. (C2, C3)

Transverse cervical runs horizontal to the anterior triangle of the neck. Note, cutaneous innervation come from the cervical plexus from nerves point in posterior triangle of the neck. The supraclavicular nerves are part of the omoclavicular triangle in the posterior triangle of the neck. The greater auricular nerve will supply cutaneous innervation in front of ear to mastoid process.

Explanation

Transverse cervical runs horizontal to the anterior triangle of the neck. Note, cutaneous innervation come from the cervical plexus from nerves point in posterior triangle of the neck. The supraclavicular nerves are part of the omoclavicular triangle in the posterior triangle of the neck. The greater auricular nerve will supply cutaneous innervation in front of ear to mastoid process.

12. A bodybuilder, after finishing his high-protein meal with a delicious protein smoothie, finds his arm in discomfort. More specifically, he has 9/10 pain on his right arm with a complete inability to flex his fifth digit. He concludes that his workout was particularly straining and that he must have compressed some nerve going to his hand. His physician agreed with his assessment, explaining that the nerve he compressed runs through a triangle of the neck formed by which of the following muscles?

Sternocleidomastoid and omohyoid

Stylohyoid and posterior belly of digastric

Anterior and posterior bellies of digastric

Scalene anterior and middle

Scalene middle and posterior

This is a description of thoracic outlet syndrome, which may be caused by a spasm of the anterior and middle scalenes compressing the lower trunk of the brachial plexus. A is the muscular triangle, B is the carotid triangle, and C is the submandibular triangle, which are all part of the anterior triangle of the neck (it is important to know the content of these spaces as well). The subclavian artery may also be compressed in this situation, leading to ischemia of the muscles of the arm. E does not see the passage of the lower trunk of the brachial plexus.

Explanation

This is a description of thoracic outlet syndrome, which may be caused by a spasm of the anterior and middle scalenes compressing the lower trunk of the brachial plexus. A is the muscular triangle, B is the carotid triangle, and C is the submandibular triangle, which are all part of the anterior triangle of the neck (it is important to know the content of these spaces as well). The subclavian artery may also be compressed in this situation, leading to ischemia of the muscles of the arm. E does not see the passage of the lower trunk of the brachial plexus.

13. A 54-yo, male, presents to your emergency clinic after being involved in a gang-related incident. He presents with multiple gun shot wounds to the chest and lacerations across his neck. An OR is quickly cleared for emergency surgery and the patient is successfully intubated and stabilized. As a vigilant medical student on your surgery rotation, you recall some of the vital structures in the anterior triangle of the neck proximal to some of the patient's lacerations. In particular you observe that the patient is having trouble swallowing and speaking because the muscles that depress and stabilize the hyoid bone are damaged. In particular, which of these muscles is innervated by a branch of the cervical plexus whose nerve only contains one spinal level contribution?

Sternohyoid m

Omohyoid m.

Sternothyroid m.

Thyrohyoid m

Sternocleidomastoid m.

The thyrohyoid muscle is the only "STRAP" muscle that is innervated strictly by C1 of the ansa cervicalis (C1, C2, C3).

Explanation

The thyrohyoid muscle is the only "STRAP" muscle that is innervated strictly by C1 of the ansa cervicalis (C1, C2, C3).

14. A 17 year old male sustains a stab wound to the upper left chest. He is brought into the emergency room with asymmetrical breathing and the physician suspects he has insufficient diaphragm movement on the left side. One would find the damaged structure passing over what landmark?

Anterior to the anterior scalene muscle

Between anterior and middle scalene muscles

In a triangle bounded by both anterior digastric muscles

Superficial to the sternocleidomastoid muscle

The structure in question here is the phrenic nerve, as the patient's left hemidiaphragm has been paralyzed by the stab wound. The phrenic nerve can be found passing over the anterior scalene. (B) the subclavian artery and brachial plexus can be found between anterior and middle scalenes. (C) the submental lymph nodes and anterior jugular vein can be found in the submental triangle bounded by both anterior digastric muscles and the hyoid bone. (D) The external jugular vein passes superficial to the SCM.

Explanation

The structure in question here is the phrenic nerve, as the patient's left hemidiaphragm has been paralyzed by the stab wound. The phrenic nerve can be found passing over the anterior scalene. (B) the subclavian artery and brachial plexus can be found between anterior and middle scalenes. (C) the submental lymph nodes and anterior jugular vein can be found in the submental triangle bounded by both anterior digastric muscles and the hyoid bone. (D) The external jugular vein passes superficial to the SCM.

15. Patient walks into the clinic complaining of irritation towards the back of the mouth. Being a sharp physician you make an automatic assumption. Thinking back to anatomy you remember what nerve pierces through the piriform recess and also remember that food may get stuck here. What nerve is it?

Vagus nerve as it does not even divide before reaching the viscera

Internal Laryngeal nerve.

Glossopharyngeal nerve on its way to the Stylopharyngeus

Optic nerve as it begins in the occipital lobe, tracks through the piriform and back up to the orbit

The Vagus nerves as it runs lateral to the Superior Cervical ganglion branches into the Superior Laryngeal. The Superior Larngyeal then branches into the Internal Laryngeal and External Laryngeal. Remember the Internal Laryngeal passes through the piriform recess on its way to provide sensation for the Thyrohoid membrane.

Explanation

The Vagus nerves as it runs lateral to the Superior Cervical ganglion branches into the Superior Laryngeal. The Superior Larngyeal then branches into the Internal Laryngeal and External Laryngeal. Remember the Internal Laryngeal passes through the piriform recess on its way to provide sensation for the Thyrohoid membrane.

16. The posterior cervical triangle contains an important accessory muscle of respiration. This muscle is named______________and is innervated by Cervical Nerves_______________The posterior triangle also contains______________ .

Anterior Scalene, C3-C8, Roots of the Brachial Plexus

Anterior Scalene, C3-C8, Trunks of the Brachial Plexus

Posterior Scalene, C3-C6, Brachial Plexus Roots

Sternocleidomastoid,C3-C6, Brachial Plexus Trunks

The correct answer is Anterior Scalene, C3-C8, Trunks of the Brachial Plexus. The anterior scalene muscle is located in the posterior cervical triangle and is an important accessory muscle of respiration. It is innervated by the cervical nerves C3-C8. The posterior triangle also contains the trunks of the brachial plexus, which are responsible for innervating the upper limb.

Explanation

The correct answer is Anterior Scalene, C3-C8, Trunks of the Brachial Plexus. The anterior scalene muscle is located in the posterior cervical triangle and is an important accessory muscle of respiration. It is innervated by the cervical nerves C3-C8. The posterior triangle also contains the trunks of the brachial plexus, which are responsible for innervating the upper limb.

17. A Spanish surgeon is conducting the world's first ever face transplant surgery for a victim of gunshot wounds. In addition to other preparatory steps, the surgeon needs to ligate a major artery before proceeding with removal of tissue from the face. In which triangle should the surgeon start his surgical approach to gain access to this artery?

Posterior triangle

Submental triangle

Submandibular triangle

Carotid triangle

Muscular triangle

Since the surgeon is doing a facial transplant, he is mostly concerned with the blood flow arriving from the facial artery. The facial artery branches slightly posterior and inferior to the angle of the mandible, placing it in the superior and posterior corner of the submandibular triangle. Therefore, choice C is the correct answer. Reference: Chuadhary, Triangles of the Neck, Slide 14.

Explanation

Since the surgeon is doing a facial transplant, he is mostly concerned with the blood flow arriving from the facial artery. The facial artery branches slightly posterior and inferior to the angle of the mandible, placing it in the superior and posterior corner of the submandibular triangle. Therefore, choice C is the correct answer. Reference: Chuadhary, Triangles of the Neck, Slide 14.

18. A 25-year-old bus rider is brought into the emergency room following a multi-vehicle accident involving the bus he was taking, a garbage truck, and a tractor that caused the bus to flip on its side. Among the many complaints with which this patient presents is a noticeable unilateral defect of inspiration and expiration with traumatic injury to his neck. The physician suspects that the problems of breathing are due to a lesion in which of the following areas of the neck?

Submandibular triangle

Carotid triangle

Submental triangle

Posterior triangle

Muscular triangle

This is likely a lesion of the phrenic nerve, which runs just posterior to the sternocleidomastoid muscle in the posterior triangle to innervate the diaphragm. Unilateral lesion of this nerve would lead to the breathing problems presented here. Lesions in the other triangles, while likely to have significant consequences, would not present with this problem.

Explanation

This is likely a lesion of the phrenic nerve, which runs just posterior to the sternocleidomastoid muscle in the posterior triangle to innervate the diaphragm. Unilateral lesion of this nerve would lead to the breathing problems presented here. Lesions in the other triangles, while likely to have significant consequences, would not present with this problem.