Gray's Anatomy Review
- Back and Upper Limb
Exam Questions Verified
and Provided with A+
Graded Answers |Latest
Updated 2026/2027
,11 A 27-year-old man is admitted to the emergency department after a car crash. Physical
examination reveals weakness during medial rotation and adduction of the humerus.
Which of the following nerves was most probably injured? A. Thoracodorsal B. Axillary C.
Dorsal scapular D. Spinal accessory E. Radial
@ 11 A. The thoracodorsal nerve innervates the latissimus dorsi, one of major muscles
that adduct and medially rotate the humerus. The axillary nerve supplies the deltoid
muscle, the dorsal scapular nerve supplies the rhomboids and levator scapulae muscles,
and the spinal accessory nerve innervates the trapezius. None of these nerves medially
rotates or adducts the humerus. The radial nerve is responsible for the innervation on
the posterior aspect of the arm and forearm. The medial and lateral pectoral nerves and
the lower
subscapular nerve supply the other medial rotators of the humerus. GAS 87, 99; N 174;
McM 101
12 A 39-year-old woman complains of an inability to reach the top of her head to brush
her hair with her right hand. History reveals that she had undergone a mastectomy
procedure of her right breast 2 months earlier. Physical examination demonstrates
winging of her right scapula. Which nerves were most likely damaged during surgery? A.
Axillary B. Spinal accessory C. Long thoracic D. Dorsal scapular E. Thoracodorsal
12 C. The long thoracic nerve innervates the serratus anterior, which is responsible for
elevation and protraction of the scapula beyond the horizontal level while maintaining its
position against the thoracic wall. Along with the thoracodorsal nerve, the long thoracic
nerve runs superficially along the thoracic wall and is subject to injury during a
mastectomy procedure. The axillary nerve, the spinal accessory nerve, and the
thoracodorsal nerve supply the deltoid muscle, trapezius muscle, and latissimus dorsi
muscles, respectively. The dorsal scapular nerve is responsible for innervation of the
rhomboids and levator scapulae. Aside from the long thoracic and thoracodorsal nerves,
the remaining nerves do not course along the lateral thoracic wall. GAS 726; N 180, 413;
McM 140
,13 A 19-year-old man is brought to the emergency department after dislocating his
shoulder while playing football. Following treatment of the dislocation, he cannot initiate
abduction of his arm. An MRI of the affected shoulder shows a torn muscle. Which muscle
was most likely damaged by the injury? A. Coracobrachialis B. Long head of the triceps
brachii C. Pectoralis minor D. Supraspinatus E. Teres major
13 D. The rotator cuff muscles are common sites of damage during shoulder injuries. These
muscles include the supraspinatus, infraspinatus, teres minor, and subscapularis (SITS).
Initiation of abduction of the humerus (the first 15 degrees) is performed by the
supraspinatus, followed by the deltoid from 15 to 90 degrees. Above the horizontal, the
scapula is rotated by the trapezius and serratus anterior muscles, causing the glenoid
fossa to turn superiorly and allowing the humerus to move above 90 degrees. The teres
major and the pectoralis major are responsible for medial rotation and adduction of the
humerus. These muscles are therefore not involved in abduction at the glenohumeral joint.
GAS 711-712, 717; N 134-135; McM 411, 413
, 14 A 1-year-old girl is brought to the clinic for a routine checkup. The child appears normal
except for a dimpling of the skin in the midline of the lumbar region with a tuft of hair
growing over the dimple. What is this relatively common condition that results from
incomplete embryologic development? A. Meningomyelocele B. Meningocele C. Spina
bifida occulta D. Spina bifida cystica E. Rachischisis
14 C. Spina bifida is a developmental condition resulting from incomplete fusion of
the vertebral arches within the lumbar region. Spina bifida occulta commonly
presents asymptomatically with midline, lumbar, cutaneous stigmata such as a tuft of
hair and a
small dimple. More severe forms (spina bifida cystica) are categorized into three types:
Spina bifida cystica with meningocele presents with protrusion of the meninges through
the unfused vertebral arches; spina bifida with myelomeningocele is characterized by
protrusion both of the meninges and central nervous system (CNS) tissues and is
often associated with neurologic deficits; and rachischisis, also known as spina bifida
cystica with myeloschisis, results from a failure of neural folds to fuse and is
characterized by
protrusion of the spinal cord or spinal nerves and meninges. GAS 74; N 14, 160; McM 77, 88
15 A young resident complains of an itch on his back that appears to be caused by an
insect bite. Which nerve fibers carry the sensation of a mosquito bite on the back, just
lateral to the spinous process of the T4 vertebra? A. Somatic afferent B. Somatic efferent
C. Visceral afferent D. Visceral efferent E. Somatic efferent and visceral afferent
15 A. Somatic afferents are responsible for conveying pain, pressure, touch, temperature,
and proprioception to the CNS. Afferent fibers carry only sensory stimuli, whereas
efferent fibers convey motor information. Visceral innervation is associated with the
autonomic nervous system. Visceral afferents generally carry information regarding the
physiologic changes of the internal viscera whereas visceral efferents deliver autonomic
motor function to three types of tissue: smooth muscle, cardiac muscle, and glandular
epithelium. GAS 32-35; N 174; McM 211
- Back and Upper Limb
Exam Questions Verified
and Provided with A+
Graded Answers |Latest
Updated 2026/2027
,11 A 27-year-old man is admitted to the emergency department after a car crash. Physical
examination reveals weakness during medial rotation and adduction of the humerus.
Which of the following nerves was most probably injured? A. Thoracodorsal B. Axillary C.
Dorsal scapular D. Spinal accessory E. Radial
@ 11 A. The thoracodorsal nerve innervates the latissimus dorsi, one of major muscles
that adduct and medially rotate the humerus. The axillary nerve supplies the deltoid
muscle, the dorsal scapular nerve supplies the rhomboids and levator scapulae muscles,
and the spinal accessory nerve innervates the trapezius. None of these nerves medially
rotates or adducts the humerus. The radial nerve is responsible for the innervation on
the posterior aspect of the arm and forearm. The medial and lateral pectoral nerves and
the lower
subscapular nerve supply the other medial rotators of the humerus. GAS 87, 99; N 174;
McM 101
12 A 39-year-old woman complains of an inability to reach the top of her head to brush
her hair with her right hand. History reveals that she had undergone a mastectomy
procedure of her right breast 2 months earlier. Physical examination demonstrates
winging of her right scapula. Which nerves were most likely damaged during surgery? A.
Axillary B. Spinal accessory C. Long thoracic D. Dorsal scapular E. Thoracodorsal
12 C. The long thoracic nerve innervates the serratus anterior, which is responsible for
elevation and protraction of the scapula beyond the horizontal level while maintaining its
position against the thoracic wall. Along with the thoracodorsal nerve, the long thoracic
nerve runs superficially along the thoracic wall and is subject to injury during a
mastectomy procedure. The axillary nerve, the spinal accessory nerve, and the
thoracodorsal nerve supply the deltoid muscle, trapezius muscle, and latissimus dorsi
muscles, respectively. The dorsal scapular nerve is responsible for innervation of the
rhomboids and levator scapulae. Aside from the long thoracic and thoracodorsal nerves,
the remaining nerves do not course along the lateral thoracic wall. GAS 726; N 180, 413;
McM 140
,13 A 19-year-old man is brought to the emergency department after dislocating his
shoulder while playing football. Following treatment of the dislocation, he cannot initiate
abduction of his arm. An MRI of the affected shoulder shows a torn muscle. Which muscle
was most likely damaged by the injury? A. Coracobrachialis B. Long head of the triceps
brachii C. Pectoralis minor D. Supraspinatus E. Teres major
13 D. The rotator cuff muscles are common sites of damage during shoulder injuries. These
muscles include the supraspinatus, infraspinatus, teres minor, and subscapularis (SITS).
Initiation of abduction of the humerus (the first 15 degrees) is performed by the
supraspinatus, followed by the deltoid from 15 to 90 degrees. Above the horizontal, the
scapula is rotated by the trapezius and serratus anterior muscles, causing the glenoid
fossa to turn superiorly and allowing the humerus to move above 90 degrees. The teres
major and the pectoralis major are responsible for medial rotation and adduction of the
humerus. These muscles are therefore not involved in abduction at the glenohumeral joint.
GAS 711-712, 717; N 134-135; McM 411, 413
, 14 A 1-year-old girl is brought to the clinic for a routine checkup. The child appears normal
except for a dimpling of the skin in the midline of the lumbar region with a tuft of hair
growing over the dimple. What is this relatively common condition that results from
incomplete embryologic development? A. Meningomyelocele B. Meningocele C. Spina
bifida occulta D. Spina bifida cystica E. Rachischisis
14 C. Spina bifida is a developmental condition resulting from incomplete fusion of
the vertebral arches within the lumbar region. Spina bifida occulta commonly
presents asymptomatically with midline, lumbar, cutaneous stigmata such as a tuft of
hair and a
small dimple. More severe forms (spina bifida cystica) are categorized into three types:
Spina bifida cystica with meningocele presents with protrusion of the meninges through
the unfused vertebral arches; spina bifida with myelomeningocele is characterized by
protrusion both of the meninges and central nervous system (CNS) tissues and is
often associated with neurologic deficits; and rachischisis, also known as spina bifida
cystica with myeloschisis, results from a failure of neural folds to fuse and is
characterized by
protrusion of the spinal cord or spinal nerves and meninges. GAS 74; N 14, 160; McM 77, 88
15 A young resident complains of an itch on his back that appears to be caused by an
insect bite. Which nerve fibers carry the sensation of a mosquito bite on the back, just
lateral to the spinous process of the T4 vertebra? A. Somatic afferent B. Somatic efferent
C. Visceral afferent D. Visceral efferent E. Somatic efferent and visceral afferent
15 A. Somatic afferents are responsible for conveying pain, pressure, touch, temperature,
and proprioception to the CNS. Afferent fibers carry only sensory stimuli, whereas
efferent fibers convey motor information. Visceral innervation is associated with the
autonomic nervous system. Visceral afferents generally carry information regarding the
physiologic changes of the internal viscera whereas visceral efferents deliver autonomic
motor function to three types of tissue: smooth muscle, cardiac muscle, and glandular
epithelium. GAS 32-35; N 174; McM 211
