COMSAE PHASE 1 ANATOMY-TO-CLINICAL
CORRELATIONS PRACTICE EXAM WITH
QUESTIONS AND VERIFIED ANSWERS,
PLUS DETAILED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1.
A 27-year-old man sustains a deep laceration to the posterior aspect of
his arm after falling onto broken glass. Examination shows weakness in
elbow extension and difficulty extending the wrist and fingers. Sensation
is decreased over the dorsal first web space. Which structure is most
likely injured?
A. Ulnar nerve
B. Median nerve
C. Radial nerve
D. Musculocutaneous nerve
E. Axillary nerve
Answer: C. Radial nerve
Rationale: The radial nerve supplies the triceps brachii and, through
its deep branch/posterior interosseous continuation, the major wrist
and finger extensors. Injury to the radial nerve in the posterior arm
can therefore produce weakness of elbow extension if proximal
enough and wrist/finger extension if the lesion involves the motor
fibers continuing distally. Sensory loss over the dorsal first web space
is particularly characteristic of radial nerve injury. The ulnar nerve
would primarily affect intrinsic hand muscles and sensation of the
fifth and medial fourth digits; the median nerve affects most forearm
1
,flexors and the thenar muscles; the musculocutaneous nerve supplies
the anterior arm; and the axillary nerve supplies the deltoid and teres
minor.
2.
A 64-year-old woman develops sudden inability to abduct her right eye.
Examination reveals horizontal diplopia that is worse when she looks
toward the affected side. Which cranial nerve is most likely affected?
A. CN III
B. CN IV
C. CN V1
D. CN VI
E. CN VII
Answer: D. CN VI
Rationale: The abducens nerve innervates the lateral rectus muscle,
which abducts the eye. A CN VI lesion therefore causes an unopposed
medial rectus, producing medial deviation of the affected eye and
horizontal diplopia. CN III supplies the medial, superior, and inferior
recti, inferior oblique, and levator palpebrae, while CN IV supplies the
superior oblique. CN VI has a long intracranial course and is
particularly vulnerable to increased intracranial pressure.
3.
A patient undergoes thyroidectomy for a large thyroid nodule. Several
hours after surgery, he develops hoarseness and difficulty producing
high-pitched sounds. Injury to which nerve most directly explains these
findings?
2
,A. Recurrent laryngeal nerve
B. Phrenic nerve
C. Hypoglossal nerve
D. Glossopharyngeal nerve
E. Greater auricular nerve
Answer: A. Recurrent laryngeal nerve
Rationale: The recurrent laryngeal nerves provide motor innervation
to nearly all intrinsic muscles of the larynx except the cricothyroid.
They travel closely with the inferior thyroid artery and are therefore
vulnerable during thyroid surgery. Injury commonly causes
hoarseness because of impaired vocal fold movement. The external
branch of the superior laryngeal nerve innervates the cricothyroid and
is especially important for tensioning the vocal cords and producing
high-pitched sounds, but the recurrent laryngeal nerve is the classic
nerve injured during thyroidectomy and best explains postoperative
vocal dysfunction.
4.
A 19-year-old athlete sustains an anterior shoulder dislocation. After
reduction, he has difficulty abducting his arm from approximately 15° to
90° and has decreased sensation over the lateral aspect of the shoulder.
Which nerve was most likely injured?
A. Suprascapular nerve
B. Axillary nerve
C. Musculocutaneous nerve
D. Radial nerve
E. Long thoracic nerve
Answer: B. Axillary nerve
3
, Rationale: The axillary nerve passes around the surgical neck of the
humerus with the posterior circumflex humeral artery and is
particularly vulnerable during anterior shoulder dislocation. It
innervates the deltoid, which is responsible for abduction from
approximately 15° to 90°, and supplies cutaneous sensation over the
lateral shoulder via the superior lateral cutaneous nerve of the arm.
The suprascapular nerve initiates abduction through supraspinatus
but does not supply the characteristic sensory territory over the lateral
shoulder.
5.
A 42-year-old man develops winging of the scapula following surgical
excision of a mass near the lateral thoracic wall. When he pushes against
a wall, the medial border of his scapula protrudes posteriorly. Which
muscle has been denervated?
A. Rhomboid major
B. Trapezius
C. Serratus anterior
D. Levator scapulae
E. Pectoralis minor
Answer: C. Serratus anterior
Rationale: The serratus anterior is innervated by the long thoracic
nerve, which descends along the lateral thoracic wall and is vulnerable
during surgical procedures in this region. Serratus anterior holds the
scapula against the thoracic wall and protracts and upwardly rotates
it. Paralysis produces medial scapular winging, especially when the
patient pushes against resistance. The dorsal scapular nerve supplies
the rhomboids, whereas the spinal accessory nerve supplies the
trapezius; injuries to those structures can also produce scapular
abnormalities but have different patterns.
4
CORRELATIONS PRACTICE EXAM WITH
QUESTIONS AND VERIFIED ANSWERS,
PLUS DETAILED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1.
A 27-year-old man sustains a deep laceration to the posterior aspect of
his arm after falling onto broken glass. Examination shows weakness in
elbow extension and difficulty extending the wrist and fingers. Sensation
is decreased over the dorsal first web space. Which structure is most
likely injured?
A. Ulnar nerve
B. Median nerve
C. Radial nerve
D. Musculocutaneous nerve
E. Axillary nerve
Answer: C. Radial nerve
Rationale: The radial nerve supplies the triceps brachii and, through
its deep branch/posterior interosseous continuation, the major wrist
and finger extensors. Injury to the radial nerve in the posterior arm
can therefore produce weakness of elbow extension if proximal
enough and wrist/finger extension if the lesion involves the motor
fibers continuing distally. Sensory loss over the dorsal first web space
is particularly characteristic of radial nerve injury. The ulnar nerve
would primarily affect intrinsic hand muscles and sensation of the
fifth and medial fourth digits; the median nerve affects most forearm
1
,flexors and the thenar muscles; the musculocutaneous nerve supplies
the anterior arm; and the axillary nerve supplies the deltoid and teres
minor.
2.
A 64-year-old woman develops sudden inability to abduct her right eye.
Examination reveals horizontal diplopia that is worse when she looks
toward the affected side. Which cranial nerve is most likely affected?
A. CN III
B. CN IV
C. CN V1
D. CN VI
E. CN VII
Answer: D. CN VI
Rationale: The abducens nerve innervates the lateral rectus muscle,
which abducts the eye. A CN VI lesion therefore causes an unopposed
medial rectus, producing medial deviation of the affected eye and
horizontal diplopia. CN III supplies the medial, superior, and inferior
recti, inferior oblique, and levator palpebrae, while CN IV supplies the
superior oblique. CN VI has a long intracranial course and is
particularly vulnerable to increased intracranial pressure.
3.
A patient undergoes thyroidectomy for a large thyroid nodule. Several
hours after surgery, he develops hoarseness and difficulty producing
high-pitched sounds. Injury to which nerve most directly explains these
findings?
2
,A. Recurrent laryngeal nerve
B. Phrenic nerve
C. Hypoglossal nerve
D. Glossopharyngeal nerve
E. Greater auricular nerve
Answer: A. Recurrent laryngeal nerve
Rationale: The recurrent laryngeal nerves provide motor innervation
to nearly all intrinsic muscles of the larynx except the cricothyroid.
They travel closely with the inferior thyroid artery and are therefore
vulnerable during thyroid surgery. Injury commonly causes
hoarseness because of impaired vocal fold movement. The external
branch of the superior laryngeal nerve innervates the cricothyroid and
is especially important for tensioning the vocal cords and producing
high-pitched sounds, but the recurrent laryngeal nerve is the classic
nerve injured during thyroidectomy and best explains postoperative
vocal dysfunction.
4.
A 19-year-old athlete sustains an anterior shoulder dislocation. After
reduction, he has difficulty abducting his arm from approximately 15° to
90° and has decreased sensation over the lateral aspect of the shoulder.
Which nerve was most likely injured?
A. Suprascapular nerve
B. Axillary nerve
C. Musculocutaneous nerve
D. Radial nerve
E. Long thoracic nerve
Answer: B. Axillary nerve
3
, Rationale: The axillary nerve passes around the surgical neck of the
humerus with the posterior circumflex humeral artery and is
particularly vulnerable during anterior shoulder dislocation. It
innervates the deltoid, which is responsible for abduction from
approximately 15° to 90°, and supplies cutaneous sensation over the
lateral shoulder via the superior lateral cutaneous nerve of the arm.
The suprascapular nerve initiates abduction through supraspinatus
but does not supply the characteristic sensory territory over the lateral
shoulder.
5.
A 42-year-old man develops winging of the scapula following surgical
excision of a mass near the lateral thoracic wall. When he pushes against
a wall, the medial border of his scapula protrudes posteriorly. Which
muscle has been denervated?
A. Rhomboid major
B. Trapezius
C. Serratus anterior
D. Levator scapulae
E. Pectoralis minor
Answer: C. Serratus anterior
Rationale: The serratus anterior is innervated by the long thoracic
nerve, which descends along the lateral thoracic wall and is vulnerable
during surgical procedures in this region. Serratus anterior holds the
scapula against the thoracic wall and protracts and upwardly rotates
it. Paralysis produces medial scapular winging, especially when the
patient pushes against resistance. The dorsal scapular nerve supplies
the rhomboids, whereas the spinal accessory nerve supplies the
trapezius; injuries to those structures can also produce scapular
abnormalities but have different patterns.
4
