Root of the Neck — MCQs
The thyrocervical trunk is a branch of which part of subclavian artery?
Superior sulcus tumor of the lungs characteristically presents with:
Which of the following structures is NOT innervated by the phrenic nerve?
All of the following arteries are branches of ECA that supply nasal septum except:
A patient has carcinoma on the right side of anterior 2/3rd of the tongue with lymph node of size 4cm in level 3 on the left side of the neck. Stage of the disease is
All are true regarding brachial plexus injury, except:
Which of the following is NOT a feature of Horner's syndrome?
A patient presents with winging of the scapula. Which nerve is most likely involved?
The internal thoracic artery is a branch of which vessel?
Which structure is most likely injured in a 25-year-old man with a bullet wound in the neck, resulting in a tension pneumothorax and collapse of the right lung?
Root of the Neck Indian Medical PG Practice Questions and MCQs
Question 1: The thyrocervical trunk is a branch of which part of subclavian artery?
- A. 1st part (Correct Answer)
- B. 2nd part
- C. 3rd part
- D. 4th part
Explanation: ***1st part*** - The **thyrocervical trunk** is one of the three primary branches arising from the **first part** of the subclavian artery. - The first part lies medial to the **anterior scalene muscle**. *2nd part* - The **second part** of the subclavian artery gives rise to the **costocervical trunk**. - This part lies posterior to the **anterior scalene muscle**. *3rd part* - The **third part** of the subclavian artery typically has no branches or may give off the **dorsal scapular artery**. - This part lies lateral to the **anterior scalene muscle**. *4th part* - This option is incorrect as the **subclavian artery has only three parts**, divided by their relationship to the anterior scalene muscle. - There is no anatomical fourth part of the subclavian artery.
Question 2: Superior sulcus tumor of the lungs characteristically presents with:
- A. Breathlessness
- B. Hemoptysis
- C. Pancoast syndrome (Correct Answer)
- D. Horner's syndrome
Explanation: ***Pancoast syndrome*** - A **superior sulcus tumor**, specifically a Pancoast tumor, is defined by its characteristic presentation as **Pancoast syndrome**. - This syndrome includes a constellation of symptoms resulting from the tumor's invasion of surrounding structures, such as the **brachial plexus**, **cervical sympathetic chain**, and **vertebral bodies**. *Horner's syndrome* - **Horner's syndrome** is a *component* of Pancoast syndrome, caused by the tumor's invasion of the **cervical sympathetic chain**. - While it's a key feature, it doesn't encompass the entire clinical presentation of a superior sulcus tumor, which also includes shoulder and arm pain due to brachial plexus involvement. *Breathlessness* - **Shortness of breath** is a general symptom of many lung conditions, including central lung tumors [1], but it is **not characteristic** of a superior sulcus tumor's typical presentation. - Superior sulcus tumors are located peripherally at the lung apex and often present with local invasive symptoms rather than respiratory distress unless very advanced [2]. *Hemoptysis* - **Hemoptysis** (coughing up blood) is more commonly associated with tumors invading central airways or large vessels [1], but it is **not a characteristic initial presentation** of a superior sulcus tumor. - The location of a superior sulcus tumor in the lung apex makes bleeding into the airways less likely as a primary symptom.
Question 3: Which of the following structures is NOT innervated by the phrenic nerve?
- A. Diaphragm
- B. Mediastinal pleura
- C. Serratus anterior (Correct Answer)
- D. Pericardium
Explanation: ***Serratus anterior*** - The **serratus anterior** muscle is innervated by the **long thoracic nerve (roots C5, C6, C7)**, not the phrenic nerve. - Its primary actions are to protract and rotate the scapula, and it is crucial for overhead arm movements. *Diaphragm* - The **diaphragm** is primarily innervated by the **phrenic nerve (C3, C4, C5)**, which is essential for its role in respiration [1]. - Sensory fibers from the phrenic nerve also supply the central part of the diaphragm. *Mediastinal pleura* - The **mediastinal pleura**, which lines the mediastinum, receives sensory innervation from the **phrenic nerve**. - Irritation of this pleura can cause referred pain to the shoulder, due to shared innervation origins. *Pericardium* - The **fibrous pericardium** and the **parietal layer of the serous pericardium** are innervated by the **phrenic nerves**. - This innervation accounts for referred pain to the shoulder in conditions affecting the pericardium.
Question 4: All of the following arteries are branches of ECA that supply nasal septum except:
- A. Facial artery
- B. Superior labial artery
- C. Anterior ethmoidal artery (Correct Answer)
- D. Sphenopalatine artery
Explanation: ***Anterior ethmoidal artery*** - The **anterior ethmoidal artery** is a branch of the **ophthalmic artery**, which itself is a branch of the **internal carotid artery (ICA)**, not the external carotid artery (ECA). - It supplies the **upper anterior nasal septum** and lateral wall of the nasal cavity. *Facial artery* - The **facial artery** is a direct branch of the **external carotid artery (ECA)**. - It contributes to the blood supply of the nasal septum through its septal branches. *Superior labial artery* - The **superior labial artery** is a branch of the **facial artery**, meaning it indirectly originates from the **external carotid artery (ECA)**. - It sends a septal branch to supply the **anterior inferior part of the nasal septum**. *Sphenopalatine artery* - The **sphenopalatine artery** is a direct terminal branch of the **maxillary artery**, which is one of the terminal branches of the **external carotid artery (ECA)**. - It is the major blood supply to the **posterior nasal septum** and lateral wall, forming part of Kesselbach's plexus.
Question 5: A patient has carcinoma on the right side of anterior 2/3rd of the tongue with lymph node of size 4cm in level 3 on the left side of the neck. Stage of the disease is
- A. N0
- B. N3
- C. N2 (Correct Answer)
- D. N1
Explanation: ***N2 (Correct Answer)*** - The patient has a **contralateral lymph node** (left side neck node with right-sided primary tumor) measuring **4 cm**. - According to TNM 8th edition, this classifies as **N2c**: bilateral or contralateral lymph nodes ≤6 cm without extranodal extension (ENE-). - N2c is a subcategory of N2, making this the correct answer. - The 4 cm size is within the N2 range (>3 cm but ≤6 cm) and the contralateral location specifically indicates N2c. *N0 (Incorrect)* - **N0** indicates no regional lymph node metastasis. - This is clearly incorrect as the patient has a clinically evident 4 cm lymph node in level 3. *N3 (Incorrect)* - **N3a** requires a lymph node **>6 cm** in size, OR - **N3b** requires evidence of **extranodal extension (ENE+)**. - Since this node is 4 cm (not >6 cm) and there is no mention of extranodal extension, N3 is incorrect. *N1 (Incorrect)* - **N1** is defined as a single **ipsilateral** lymph node ≤3 cm without ENE. - This patient fails N1 criteria on two counts: the node is **contralateral** (not ipsilateral) and measures **4 cm** (exceeds 3 cm limit).
Question 6: All are true regarding brachial plexus injury, except:
- A. In Klumpke's palsy, Horner's syndrome may be present on the ipsilateral side
- B. Preganglionic lesions have a better prognosis than postganglionic lesions (Correct Answer)
- C. Erb's palsy causes paralysis of the abductors and external rotators of the shoulder
- D. Histamine test is useful to differentiate between the preganglionic and postganglionic lesions
Explanation: ***Preganglionic lesions have a better prognosis than postganglionic lesions*** - **Preganglionic lesions** involve the avulsion of nerve roots from the spinal cord, making nerve regeneration and surgical repair more challenging, therefore resulting in a **worse prognosis**. - In contrast, **postganglionic lesions** involve damage to the nerves distal to the dorsal root ganglion, which often allows for **spontaneous recovery** or more successful surgical intervention, leading to a better prognosis. *In Klumpke's palsy, Horner's syndrome may be present on the ipsilateral side* - **Klumpke's palsy** results from injury to the **lower trunk** of the brachial plexus (C8-T1), which can involve the sympathetic fibers that exit at T1. - Damage to these fibers can lead to **Horner's syndrome** (miosis, ptosis, anhydrosis) on the ipsilateral side. *Erb's palsy causes paralysis of the abductors and external rotators of the shoulder* - **Erb's palsy** involves injury to the **upper trunk** of the brachial plexus (C5-C6), affecting muscles innervated by these roots. - This results in paralysis of muscles such as the deltoid (abductor) and supraspinatus/infraspinatus (external rotators), leading to the characteristic "waiter's tip" posture. *Histamine test is useful to differentiate between the preganglionic and postganglionic lesions* - The **histamine test** (or histamine wheal test) is used to assess the integrity of peripheral unmyelinated postganglionic sympathetic fibers. - If a wheal and flare reaction occurs, it suggests intact postganglionic fibers, indicating a **preganglionic lesion**; absence of a reaction suggests a **postganglionic lesion**.
Question 7: Which of the following is NOT a feature of Horner's syndrome?
- A. Anhidrosis
- B. Enophthalmos
- C. Hyperchromatic iris (Correct Answer)
- D. Miosis
Explanation: ***Hyperchromatic iris*** - The iris in Horner's syndrome typically presents as **heterochromia iridis**, where the affected eye's iris is **hypochromatic (lighter)** compared to the healthy eye due to reduced melanin synthesis from sympathetic denervation - This occurs particularly with congenital or early-onset Horner's syndrome (before age 2 years) - A **hyperchromatic (darker) iris is NOT a feature** of Horner's syndrome, making this the correct answer *Anhidrosis* - **Anhidrosis** (decreased sweating) on the affected side of the face and neck is a classic feature of Horner's syndrome - Results from disruption of postganglionic sympathetic fibers supplying sweat glands in the ipsilateral facial and neck regions - Pattern of anhidrosis helps localize the lesion (central, preganglionic, or postganglionic) *Enophthalmos* - **Mild enophthalmos** (sunken eyeball appearance) occurs in Horner's syndrome - Due to paralysis of **Müller's muscle** (superior tarsal muscle), which normally helps maintain globe position - Combined with ptosis, this creates the characteristic sunken appearance of the affected eye *Miosis* - **Miosis** (pupillary constriction) is a hallmark feature of Horner's syndrome - Results from paralysis of the **iris dilator muscle** due to interrupted sympathetic innervation - Leads to unopposed parasympathetic activity, causing the characteristic small pupil - Dilation lag can be demonstrated with dim lighting or cocaine test
Question 8: A patient presents with winging of the scapula. Which nerve is most likely involved?
- A. Thoracodorsal nerve
- B. Lateral pectoral nerve
- C. Long thoracic nerve (Correct Answer)
- D. Musculocutaneous nerve
Explanation: ### Long thoracic nerve - The long thoracic nerve innervates the **serratus anterior muscle**, which is responsible for scapular protraction and upward rotation. - Damage to this nerve paralyzes the serratus anterior, leading to **winging of the scapula** as the medial border and inferior angle of the scapula become prominent. ### Thoracodorsal nerve - This nerve supplies the **latissimus dorsi muscle**, which is involved in adduction, extension, and internal rotation of the humerus [1]. - Injury to the thoracodorsal nerve would weaken movements of the shoulder, but not directly cause **scapular winging**. ### Lateral pectoral nerve - The lateral pectoral nerve innervates the **pectoralis major muscle** (upper and middle parts) [1]. - Damage to this nerve primarily affects shoulder adduction and internal rotation, but does not result in **scapular winging**. ### Musculocutaneous nerve - This nerve innervates the **coracobrachialis**, **biceps brachii**, and **brachialis muscles** in the anterior compartment of the arm. - Injury to the musculocutaneous nerve would impair elbow flexion and forearm supination, and is unrelated to **scapular movement**.
Question 9: The internal thoracic artery is a branch of which vessel?
- A. Arch of aorta
- B. Subclavian artery (Correct Answer)
- C. Superior epigastric artery
- D. Thyrocervical trunk
Explanation: Subclavian artery - The internal thoracic artery (also known as the internal mammary artery) is a direct branch of the first part of the subclavian artery. - It descends into the chest and supplies the anterior chest wall, breasts, and contributes to the supply of the diaphragm. Arch of aorta - The arch of the aorta gives off major branches such as the brachiocephalic trunk, left common carotid artery, and left subclavian artery. - While the subclavian artery originates from the arch (or the brachiocephalic trunk on the right), the internal thoracic artery is a more distal branch off the subclavian itself, not directly off the arch. Superior epigastric artery - The superior epigastric artery is actually one of the two terminal branches of the internal thoracic artery, indicating it is a distal continuation, not its origin [1]. - It descends into the rectus sheath to anastomose with the inferior epigastric artery [1]. Thyrocervical trunk - The thyrocervical trunk is a short, thick artery that arises from the first part of the subclavian artery. - Its branches (inferior thyroid, superficial cervical, and suprascapular arteries) primarily supply structures in the neck and shoulder, not the internal thoracic artery.
Question 10: Which structure is most likely injured in a 25-year-old man with a bullet wound in the neck, resulting in a tension pneumothorax and collapse of the right lung?
- A. Costal pleura
- B. Cupula (Correct Answer)
- C. Right mainstem bronchus
- D. Right upper lobe bronchus
Explanation: ***Cupula*** - The **cupula** (or cervical pleura) extends into the root of the neck, superior to the first rib, making it vulnerable to neck injuries [1]. - A penetrating injury to this region can directly damage the pleura, leading to **pneumothorax** and subsequent lung collapse [1]. *Costal pleura* - The **costal pleura** lines the inner surface of the thoracic wall and would primarily be affected by injuries directly to the chest wall, not the neck [1]. - Injury to this part of the pleura is less likely to result from a **neck wound** causing a pneumothorax unless the wound extended significantly downwards. *Right mainstem bronchus* - The **right mainstem bronchus** is located deep within the mediastinum and would typically require a much deeper and more centrally located injury to be affected. - While mainstem bronchial injuries can cause **pneumothorax**, a bullet wound in the neck is less likely to reach this structure without causing more extensive mediastinal damage. *Right upper lobe bronchus* - The **right upper lobe bronchus** is also situated within the mediastinum, deep to the pleura and lung parenchyma. - An isolated injury to this bronchus from a neck wound is unlikely; simpler, more superficial structures like the **cupula** are more probable targets.
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