Stanford University MD SURG 203 Clinical Anatomy
– Macroscopic, Microscopic, Developmental &
Imaging Anatomy Study Guide, Original Practice
Questions & Answers, Stanford Medical School
Exam Preparation, Comprehensive Anatomy
Review, Gross Anatomy, Histology, Embryology,
Developmental Anatomy, Medical Imaging,
Regional Anatomy, Thorax, Abdomen, Pelvis, Back,
Upper & Lower Limbs, Head & Neck & Clinical
Applications
Question 1: A 45-year-old patient presents with a left-sided diaphragmatic
paralysis following a thoracic surgical procedure. Which of the following
nerves is most likely to have been injured?
A. Vagus nerve
B. Phrenic nerve
C. Thoracic sympathetic trunk
D. Long thoracic nerve
CORRECT ANSWER: B. Phrenic nerve
Rationale: The phrenic nerve (C3-C5) provides the sole motor innervation to the
diaphragm. Injury to this nerve results in ipsilateral diaphragmatic paralysis. The vagus
nerve provides parasympathetic innervation to the thorax and abdomen, the
sympathetic trunk provides autonomic innervation, and the long thoracic nerve
innervates the serratus anterior.
Question 2: A 60-year-old male with a history of smoking presents with
hoarseness and a left-sided vocal cord paralysis. A chest X-ray reveals a mass
in the superior mediastinum. Which anatomical structure is most likely
compressed by this mass, leading to the patient's symptoms?
A. Left phrenic nerve
B. Left recurrent laryngeal nerve
C. Left vagus nerve
D. Left sympathetic trunk
CORRECT ANSWER: B. Left recurrent laryngeal nerve
Rationale: The left recurrent laryngeal nerve branches from the vagus nerve in the
superior mediastinum, loops under the aortic arch, and ascends to the larynx. It is
susceptible to compression by mediastinal masses, aortic aneurysms, or
lymphadenopathy, resulting in hoarseness due to paralysis of the ipsilateral vocal cord.
The right recurrent laryngeal nerve loops under the right subclavian artery.
,Question 3: A 30-year-old patient sustains a knife wound to the right side of
the neck, just superior to the clavicle. Which of the following vascular
structures is at greatest risk of injury at this location?
A. Common carotid artery
B. External carotid artery
C. Subclavian artery
D. Brachiocephalic artery
CORRECT ANSWER: C. Subclavian artery
Rationale: The subclavian artery passes posterior to the clavicle and is vulnerable to
injury from penetrating trauma just superior to the clavicle. The common and external
carotid arteries are located more superiorly in the neck, while the brachiocephalic artery
is located in the superior mediastinum.
Question 4: During a thyroidectomy, the surgeon must ligate the superior
thyroid artery. Which of the following nerves is most at risk of injury during
this procedure?
A. Recurrent laryngeal nerve
B. Hypoglossal nerve
C. External branch of the superior laryngeal nerve
D. Ansa cervicalis
CORRECT ANSWER: C. External branch of the superior laryngeal nerve
Rationale: The superior thyroid artery is closely associated with the external branch of
the superior laryngeal nerve, which innervates the cricothyroid muscle. Injury to this
nerve results in a loss of high-pitched vocalization. The recurrent laryngeal nerve is
more at risk during ligation of the inferior thyroid artery.
Question 5: A 55-year-old woman with hyperthyroidism is scheduled for a
subtotal thyroidectomy. To avoid injuring the recurrent laryngeal nerve, the
surgeon must be aware of its relationship with which of the following arteries?
A. Superior thyroid artery
B. Inferior thyroid artery
C. Middle thyroid artery
D. Thyroidea ima artery
CORRECT ANSWER: B. Inferior thyroid artery
Rationale: The recurrent laryngeal nerve typically passes posterior to the inferior thyroid
artery or between its branches. Careful dissection and identification of this relationship
are crucial during thyroidectomy to prevent vocal cord paralysis. The superior thyroid
artery is associated with the external laryngeal nerve.
,Question 6: A 25-year-old male with a stab wound to the neck is examined in
the emergency department. He is hoarse and has a flattened right diaphragm
on chest X-ray. Which of the following nerves is most likely injured?
A. Right phrenic nerve and right vagus nerve
B. Right phrenic nerve and right recurrent laryngeal nerve
C. Right vagus nerve and right sympathetic trunk
D. Right recurrent laryngeal nerve and right phrenic nerve
CORRECT ANSWER: D. Right recurrent laryngeal nerve and right phrenic
nerve
Rationale: Hoarseness indicates injury to the right recurrent laryngeal nerve, while a
flattened right diaphragm indicates injury to the right phrenic nerve. A penetrating
wound to the neck can injure both structures as they lie in close proximity in the root of
the neck.
Question 7: A 40-year-old patient with a parathyroid adenoma undergoes a
parathyroidectomy. During the procedure, the surgeon identifies a structure
that connects the inferior thyroid artery to the recurrent laryngeal nerve. What
is this anatomical structure?
A. Ligament of Berry
B. Zuckerkandl's tubercle
C. Recurrent laryngeal nerve's ansa
D. Suspensory ligament of the thyroid
CORRECT ANSWER: A. Ligament of Berry
Rationale: The ligament of Berry is a posterior thickening of the pretracheal fascia that
connects the thyroid gland to the trachea. It is in close proximity to the recurrent
laryngeal nerve and the inferior thyroid artery. The nerve often passes deep to or
through this ligament, making it a key landmark during thyroid surgery.
Question 8: A 65-year-old man presents with a painless swelling in the anterior
neck that moves with swallowing. On examination, the swelling is firm and
irregular. Which of the following embryological remnants is most likely the
origin of this mass?
A. Thyroglossal duct cyst
B. Branchial cleft cyst
C. Pyramidal lobe
D. Ectopic thyroid tissue
CORRECT ANSWER: C. Pyramidal lobe
Rationale: A pyramidal lobe is a remnant of the thyroglossal duct that extends superiorly
from the isthmus of the thyroid gland. It is present in up to 50% of the population and
can become enlarged, presenting as a midline neck mass that moves with swallowing. A
thyroglossal duct cyst also moves with swallowing but is usually cystic.
, Question 9: A 30-year-old female presents with a midline neck mass that
elevates with protrusion of the tongue. Which of the following is the most
likely diagnosis?
A. Ectopic thyroid tissue
B. Pyramidal lobe
C. Thyroglossal duct cyst
D. Branchial cleft cyst
CORRECT ANSWER: C. Thyroglossal duct cyst
Rationale: A thyroglossal duct cyst is a congenital midline neck mass that classically
moves upward with tongue protrusion due to its attachment to the foramen cecum via
the thyroglossal tract. It is the most common congenital neck mass. Branchial cleft cysts
are located laterally.
Question 10: A 5-year-old child presents with a tender, erythematous mass in
the anterior neck, just inferior to the hyoid bone. The mass is midline and
moves with swallowing. Which of the following is the most appropriate
definitive treatment?
A. Antibiotics
B. Incision and drainage
C. Sistrunk procedure
D. Excision of the cyst alone
CORRECT ANSWER: C. Sistrunk procedure
Rationale: A Sistrunk procedure is the definitive treatment for a thyroglossal duct cyst. It
involves excision of the cyst, the central portion of the hyoid bone, and a core of tissue
from the base of the tongue up to the foramen cecum. This is necessary because the
tract often passes through or deep to the hyoid bone, and simple excision of the cyst
alone results in a high recurrence rate.
Question 11: A 45-year-old man presents with a painless, cystic mass in the
anterior triangle of the neck, deep to the sternocleidomastoid muscle. Which
of the following is the most likely diagnosis?
A. Thyroglossal duct cyst
B. Branchial cleft cyst
C. Lymphangioma
D. Dermoid cyst
CORRECT ANSWER: B. Branchial cleft cyst
Rationale: Branchial cleft cysts are congenital epithelial cysts that arise from remnants of
the branchial apparatus. They typically present as painless, fluctuant masses in the
lateral neck, deep to the sternocleidomastoid muscle. A thyroglossal duct cyst is midline,
and lymphangiomas are usually in the posterior triangle.
– Macroscopic, Microscopic, Developmental &
Imaging Anatomy Study Guide, Original Practice
Questions & Answers, Stanford Medical School
Exam Preparation, Comprehensive Anatomy
Review, Gross Anatomy, Histology, Embryology,
Developmental Anatomy, Medical Imaging,
Regional Anatomy, Thorax, Abdomen, Pelvis, Back,
Upper & Lower Limbs, Head & Neck & Clinical
Applications
Question 1: A 45-year-old patient presents with a left-sided diaphragmatic
paralysis following a thoracic surgical procedure. Which of the following
nerves is most likely to have been injured?
A. Vagus nerve
B. Phrenic nerve
C. Thoracic sympathetic trunk
D. Long thoracic nerve
CORRECT ANSWER: B. Phrenic nerve
Rationale: The phrenic nerve (C3-C5) provides the sole motor innervation to the
diaphragm. Injury to this nerve results in ipsilateral diaphragmatic paralysis. The vagus
nerve provides parasympathetic innervation to the thorax and abdomen, the
sympathetic trunk provides autonomic innervation, and the long thoracic nerve
innervates the serratus anterior.
Question 2: A 60-year-old male with a history of smoking presents with
hoarseness and a left-sided vocal cord paralysis. A chest X-ray reveals a mass
in the superior mediastinum. Which anatomical structure is most likely
compressed by this mass, leading to the patient's symptoms?
A. Left phrenic nerve
B. Left recurrent laryngeal nerve
C. Left vagus nerve
D. Left sympathetic trunk
CORRECT ANSWER: B. Left recurrent laryngeal nerve
Rationale: The left recurrent laryngeal nerve branches from the vagus nerve in the
superior mediastinum, loops under the aortic arch, and ascends to the larynx. It is
susceptible to compression by mediastinal masses, aortic aneurysms, or
lymphadenopathy, resulting in hoarseness due to paralysis of the ipsilateral vocal cord.
The right recurrent laryngeal nerve loops under the right subclavian artery.
,Question 3: A 30-year-old patient sustains a knife wound to the right side of
the neck, just superior to the clavicle. Which of the following vascular
structures is at greatest risk of injury at this location?
A. Common carotid artery
B. External carotid artery
C. Subclavian artery
D. Brachiocephalic artery
CORRECT ANSWER: C. Subclavian artery
Rationale: The subclavian artery passes posterior to the clavicle and is vulnerable to
injury from penetrating trauma just superior to the clavicle. The common and external
carotid arteries are located more superiorly in the neck, while the brachiocephalic artery
is located in the superior mediastinum.
Question 4: During a thyroidectomy, the surgeon must ligate the superior
thyroid artery. Which of the following nerves is most at risk of injury during
this procedure?
A. Recurrent laryngeal nerve
B. Hypoglossal nerve
C. External branch of the superior laryngeal nerve
D. Ansa cervicalis
CORRECT ANSWER: C. External branch of the superior laryngeal nerve
Rationale: The superior thyroid artery is closely associated with the external branch of
the superior laryngeal nerve, which innervates the cricothyroid muscle. Injury to this
nerve results in a loss of high-pitched vocalization. The recurrent laryngeal nerve is
more at risk during ligation of the inferior thyroid artery.
Question 5: A 55-year-old woman with hyperthyroidism is scheduled for a
subtotal thyroidectomy. To avoid injuring the recurrent laryngeal nerve, the
surgeon must be aware of its relationship with which of the following arteries?
A. Superior thyroid artery
B. Inferior thyroid artery
C. Middle thyroid artery
D. Thyroidea ima artery
CORRECT ANSWER: B. Inferior thyroid artery
Rationale: The recurrent laryngeal nerve typically passes posterior to the inferior thyroid
artery or between its branches. Careful dissection and identification of this relationship
are crucial during thyroidectomy to prevent vocal cord paralysis. The superior thyroid
artery is associated with the external laryngeal nerve.
,Question 6: A 25-year-old male with a stab wound to the neck is examined in
the emergency department. He is hoarse and has a flattened right diaphragm
on chest X-ray. Which of the following nerves is most likely injured?
A. Right phrenic nerve and right vagus nerve
B. Right phrenic nerve and right recurrent laryngeal nerve
C. Right vagus nerve and right sympathetic trunk
D. Right recurrent laryngeal nerve and right phrenic nerve
CORRECT ANSWER: D. Right recurrent laryngeal nerve and right phrenic
nerve
Rationale: Hoarseness indicates injury to the right recurrent laryngeal nerve, while a
flattened right diaphragm indicates injury to the right phrenic nerve. A penetrating
wound to the neck can injure both structures as they lie in close proximity in the root of
the neck.
Question 7: A 40-year-old patient with a parathyroid adenoma undergoes a
parathyroidectomy. During the procedure, the surgeon identifies a structure
that connects the inferior thyroid artery to the recurrent laryngeal nerve. What
is this anatomical structure?
A. Ligament of Berry
B. Zuckerkandl's tubercle
C. Recurrent laryngeal nerve's ansa
D. Suspensory ligament of the thyroid
CORRECT ANSWER: A. Ligament of Berry
Rationale: The ligament of Berry is a posterior thickening of the pretracheal fascia that
connects the thyroid gland to the trachea. It is in close proximity to the recurrent
laryngeal nerve and the inferior thyroid artery. The nerve often passes deep to or
through this ligament, making it a key landmark during thyroid surgery.
Question 8: A 65-year-old man presents with a painless swelling in the anterior
neck that moves with swallowing. On examination, the swelling is firm and
irregular. Which of the following embryological remnants is most likely the
origin of this mass?
A. Thyroglossal duct cyst
B. Branchial cleft cyst
C. Pyramidal lobe
D. Ectopic thyroid tissue
CORRECT ANSWER: C. Pyramidal lobe
Rationale: A pyramidal lobe is a remnant of the thyroglossal duct that extends superiorly
from the isthmus of the thyroid gland. It is present in up to 50% of the population and
can become enlarged, presenting as a midline neck mass that moves with swallowing. A
thyroglossal duct cyst also moves with swallowing but is usually cystic.
, Question 9: A 30-year-old female presents with a midline neck mass that
elevates with protrusion of the tongue. Which of the following is the most
likely diagnosis?
A. Ectopic thyroid tissue
B. Pyramidal lobe
C. Thyroglossal duct cyst
D. Branchial cleft cyst
CORRECT ANSWER: C. Thyroglossal duct cyst
Rationale: A thyroglossal duct cyst is a congenital midline neck mass that classically
moves upward with tongue protrusion due to its attachment to the foramen cecum via
the thyroglossal tract. It is the most common congenital neck mass. Branchial cleft cysts
are located laterally.
Question 10: A 5-year-old child presents with a tender, erythematous mass in
the anterior neck, just inferior to the hyoid bone. The mass is midline and
moves with swallowing. Which of the following is the most appropriate
definitive treatment?
A. Antibiotics
B. Incision and drainage
C. Sistrunk procedure
D. Excision of the cyst alone
CORRECT ANSWER: C. Sistrunk procedure
Rationale: A Sistrunk procedure is the definitive treatment for a thyroglossal duct cyst. It
involves excision of the cyst, the central portion of the hyoid bone, and a core of tissue
from the base of the tongue up to the foramen cecum. This is necessary because the
tract often passes through or deep to the hyoid bone, and simple excision of the cyst
alone results in a high recurrence rate.
Question 11: A 45-year-old man presents with a painless, cystic mass in the
anterior triangle of the neck, deep to the sternocleidomastoid muscle. Which
of the following is the most likely diagnosis?
A. Thyroglossal duct cyst
B. Branchial cleft cyst
C. Lymphangioma
D. Dermoid cyst
CORRECT ANSWER: B. Branchial cleft cyst
Rationale: Branchial cleft cysts are congenital epithelial cysts that arise from remnants of
the branchial apparatus. They typically present as painless, fluctuant masses in the
lateral neck, deep to the sternocleidomastoid muscle. A thyroglossal duct cyst is midline,
and lymphangiomas are usually in the posterior triangle.
