Grays Anatomy - Upper Limb Exam
Questions and Answers
1 A 45-year-old woman is being examined as a candidate for cosmetic breast
surgery. The surgeon notes that both of her breasts sag considerably. Which
structure(s) has most likely become stretched to result in this condition?
A. Scarpa's fascia
B. Pectoralis major muscle
C. Pectoralis minor muscle
D. Suspensory (Cooper's) ligaments
E. Serratus anterior muscle - answer- D. The suspensory ligaments of the breast,
also known as Cooper's ligaments, are fibrous bands that run from the dermis of the
skin to the deep layer of superficial fascia and are primary supports for the breasts
against gravity. Ptosis of the breast is usually due to the stretching of these
ligaments and can be repaired with plastic surgery. Scarpa's fascia is the deep
membranous layer of superficial fascia of the anterior abdominal wall. The pectoralis
major and pectoralis minor are muscles that move the upper limb and lie deep to the
breast but do not provide any direct support structure to the breast. The serratus
anterior muscle is involved in the movements of the scapula.
2 A 27-year-old man was admitted to the emergency department after an automobile
collision in which he suffered a fracture of the lateral border of the scapula. Six
weeks after the accident, physical examination reveals weakness in medial rotation
and adduction of the humerus. Which nerve was most likely injured?
A. Lower subscapular
B. Axillary
C. Radial
D. Spinal accessory
E. Ulnar - answer- A. The lower subscapular nerve arises from the cervical spinal
nerves 5 and 6. It innervates the subscapularis and teres major muscles. The
subscapularis and teres major muscles are both responsible for adducting and
medially rotating the arm. A lesion of this nerve would result in weakness in these
motions. The axillary nerve also arises from cervical spinal nerves 5 and 6 and
innervates the deltoid and teres minor muscles. The deltoid muscle is large and
covers the entire surface of the shoulder, and contributes to arm movement in any
plane. The teres minor muscle is a lateral rotator and a member of the rotator cuff
group of muscles. The radial nerve arises from the posterior cord of the brachial
plexus. It is the largest branch, and it innervates the triceps brachii and anconeus
muscles in the arm. The spinal accessory nerve is cranial nerve XI, and innervates
the trapezius muscle, which elevates and depresses the scapula. The ulnar nerve
arises from the medial cord of the brachial plexus and runs down the medial aspect
of the arm. It innervates muscles of the forearm and hand.
3 A 48-year-old female court stenographer is admitted to the orthopedic clinic with
symptoms of carpal tunnel syndrome, with which she has suffered with for almost a
year. Which muscles most typically become weakened in this condition?
A. Dorsal interossei
,B. Lumbricals III and IV
C. Thenar
D. Palmar interossei
E. Hypothenar - answer- C. The thenar muscles (and lumbricals I and II) are
innervated by the median nerve, which runs through the carpal tunnel. The carpal
tunnel is formed anteriorly by the flexor retinaculum and posteriorly by the carpal
bones. Carpal tunnel syndrome is caused by a compression of the median nerve,
due to reduced space in the carpal tunnel. The carpal tunnel contains the tendons of
flexor pollicis longus, flexor digitorum profundus, and flexor digitorum superficialis
muscles and their synovial sheaths. The dorsal interossei, lumbricals III and IV ,
palmar interossei, and hypothenar muscles are all innervated by the ulnar nerve.
GAS 798, 808; N 452; McM 159
4 A 45-year-old man arrived at the emergency department with injuries to his left
elbow after he fell in a bicycle race. Plain radiographic and magnetic resonance
imaging (MRI) examinations show a fracture of the medial epicondyle and an injured
ulnar nerve. Which of the following muscles will most likely be paralyzed?
A. Flexor digitorum superficialis
B. Biceps brachii
C. Brachioradialis
D. Flexor carpi ulnaris
E. Supinator - answer- D. Fracture of the medial epicondyle often causes damage to
the ulnar nerve due to its position in the groove behind the epicondyle. The ulnar
nerve innervates one and a half muscles in the forearm, the flexor carpi ulnaris and
the medial half of the flexor digitorum profundus muscles. The nerve continues on to
innervate most of the muscles in the hand. The flexor digitorum superficialis is
innervated by the median nerve and the biceps brachii muscle by the
musculocutaneous. The radial nerve innervates both the brachioradialis and
supinator muscles.
5 While walking to his classroom building, a first year medical student slipped on the
wet pavement and fell against the curb, injuring his right arm. Radiographic images
showed a midshaft fracture of the humerus. Which pair of structures was most likely
injured at the fracture site?
A. Median nerve and brachial artery
B. Axillary nerve and posterior circumflex humeral artery
C. Radial nerve and deep brachial artery
D. Suprascapular nerve and artery
E. Long thoracic nerve and lateral thoracic artery - answer- C. A midshaft humeral
fracture can result in injury to the radial nerve and deep brachial artery because they
lie in the spiral groove located in the midshaft. Injury to the median nerve and
brachial artery can be caused by a supracondylar fracture that occurs by falling on
an outstretched hand and partially flexed elbow. A fracture of the surgical neck of the
humerus can injure the axillary nerve and posterior circumflex humeral artery. The
suprascapular artery and nerve can be injured in a shoulder dislocation. The long
thoracic nerve and lateral thoracic artery may be damaged during a mastectomy
procedure.
6 An 18-year-old man is brought to the emergency department after an injury while
playing rugby. Imaging reveals a transverse fracture of the humerus about 1 inch
,proximal to the epicondyles. Which nerve is most frequently injured by the jagged
edges of the broken bone at this location?
A. Axillary
B. Median
C. Musculocutaneous
D. Radial
E. Ulnar - answer- B. A supracondylar fracture often results in injury to the median
nerve. The course of the median nerve is anterolateral, and at the elbow it lies
medial to the brachial artery on the brachialis muscle. The axillary nerve passes
posteriorly through the quadrangular space, accompanied by the posterior circumflex
humeral artery, and winds around the surgical neck of the humerus. Injury to the
surgical neck may damage the axillary nerve. The musculocutaneous nerve pierces
the coracobrachialis muscle and descends between the biceps brachii and brachialis
muscle. It continues into the forearm as the lateral antebrachial cutaneous nerve.
The ulnar nerve descends behind the medial epicondyle in its groove and is easily
injured and produces "funny bone" symptoms.
7 A 52-year-old female band director suffered problems in her right arm several days
after strenuous field exercises for a major athletic tournament. Examination in the
orthopedic clinic reveals wrist drop and weakness of grasp but normal extension of
the elbow joint. There is no loss of sensation in the affected limb. Which nerve was
most likely affected?
A. Ulnar
B. Anterior interosseous
C. Posterior interosseous
D. Median
E. Superficial radial - answer- C. The radial nerve descends posteriorly between the
long and lateral heads of the triceps brachii muscle and passes inferolaterally on the
back of the humerus between the medial and lateral heads of the triceps brachii
muscle. It eventually enters the anterior compartment and descends to enter the
cubital fossa, where it divides into superficial and deep branches. The deep branch
of the radial nerve winds laterally around the radius and runs between the two heads
of the supinator muscle and continues as the posterior interosseous nerve,
innervating extensor muscles of the forearm. Because this injury does not result in
loss of sensation over the skin of the upper limb, it is likely that the superficial branch
of the radial nerve is not injured. If the radial nerve were injured very proximally, the
woman would not be able to extend her elbow. The branches of the radial nerve to
the triceps brachii muscle arise proximal to where the nerve runs in the spiral groove.
The anterior interosseous nerve arises from the median nerve and supplies the
flexor digitorum profundus, flexor pollicis longus, and pronator quadratus muscles,
none of which seem to be injured in this example. Injury to the median nerve causes
a characteristic flattening (atrophy) of the thenar eminence.
8 A 32-year-old woman is admitted to the emergency department after an
automobile collision. Radiologic examination reveals multiple fractures of the
humerus. Flexion and supination of the forearm are severely weakened. She also
has loss of sensation on the lateral surface of the forearm. Which of the following
nerves has most likely been injured?
A. Radial
B. Musculocutaneous
, C. Median
D. Lateral cord of brachial plexus
E. Lateral cutaneous nerve of the forearm - answer- B. The musculocutaneous nerve
supplies the biceps brachii and brachialis muscles, which are the flexors of the
forearm at the elbow. The musculocutaneous nerve continues as the lateral
antebrachial cutaneous nerve, which supplies sensation to the lateral side of the
forearm (with the forearm in the anatomic position). The biceps brachii muscle is the
most powerful supinator muscle. Injury to this nerve would result in weakness of
supination and forearm flexion and lateral forearm sensory loss. Injury to the radial
nerve would result in weakened extension and a characteristic wrist drop. Injury to
the median nerve causes paralysis of flexor digitorum superficialis muscle and other
flexors in the forearm and results in a characteristic flattening of the thenar
eminence. The lateral cord of the brachial plexus gives origin both to the
musculocutaneous and lateral pectoral nerves. There is no indication of pectoral
paralysis or weakness. Injury to the lateral cord can result in weakened flexion and
supination in the forearm, and weakened adduction and medial rotation of the arm.
The lateral cutaneous nerve of the forearm is a branch of the musculocutaneous
nerve and does not supply any motor innervation. Injury to the musculocutaneous
nerve alone is unusual but can follow penetrating injuries.
9 A 24-year-old female medical student was bitten at the base of her thumb by her
dog. The wound became infected and the infection spread into the radial bursa. The
tendon(s) of which muscle will most likely be affected?
A. Flexor digitorum profundus
B. Flexor digitorum superficialis
C. Flexor pollicis longus
D. Flexor carpi radialis
E. Flexor pollicis brevis - answer- C. Tenosynovitis can be due to an infection of the
synovial sheaths of the digits. Tenosynovitis in the thumb may spread through the
synovial sheath of the flexor pollicis longus tendon, also known as the radial bursa.
The tendons of the flexor digitorum superficialis and profundus muscles are
enveloped in the common synovial flexor sheath or ulnar bursa. Neither the flexor
carpi radialis nor flexor pollicis brevis tendons are contained in synovial flexor
sheaths.
10 Laboratory studies in the outpatient clinic on a 24-year-old woman included
assessment of circulating blood chemistry. Which of the following arteries is most
likely at risk during venipuncture at the cubital fossa?
A. Brachial
B. Common interosseous
C. Ulnar
D. Anterior interosseous
E. Radial - answer- A. The three chief contents of the cubital fossa are the biceps
brachii tendon, brachial artery, and median nerve (lateral to medial). The common
and anterior interosseous arteries arise distal to the cubital fossa; the ulnar and
radial arteries are the result of the bifurcation of the brachial artery distal to the
cubital fossa.
Questions and Answers
1 A 45-year-old woman is being examined as a candidate for cosmetic breast
surgery. The surgeon notes that both of her breasts sag considerably. Which
structure(s) has most likely become stretched to result in this condition?
A. Scarpa's fascia
B. Pectoralis major muscle
C. Pectoralis minor muscle
D. Suspensory (Cooper's) ligaments
E. Serratus anterior muscle - answer- D. The suspensory ligaments of the breast,
also known as Cooper's ligaments, are fibrous bands that run from the dermis of the
skin to the deep layer of superficial fascia and are primary supports for the breasts
against gravity. Ptosis of the breast is usually due to the stretching of these
ligaments and can be repaired with plastic surgery. Scarpa's fascia is the deep
membranous layer of superficial fascia of the anterior abdominal wall. The pectoralis
major and pectoralis minor are muscles that move the upper limb and lie deep to the
breast but do not provide any direct support structure to the breast. The serratus
anterior muscle is involved in the movements of the scapula.
2 A 27-year-old man was admitted to the emergency department after an automobile
collision in which he suffered a fracture of the lateral border of the scapula. Six
weeks after the accident, physical examination reveals weakness in medial rotation
and adduction of the humerus. Which nerve was most likely injured?
A. Lower subscapular
B. Axillary
C. Radial
D. Spinal accessory
E. Ulnar - answer- A. The lower subscapular nerve arises from the cervical spinal
nerves 5 and 6. It innervates the subscapularis and teres major muscles. The
subscapularis and teres major muscles are both responsible for adducting and
medially rotating the arm. A lesion of this nerve would result in weakness in these
motions. The axillary nerve also arises from cervical spinal nerves 5 and 6 and
innervates the deltoid and teres minor muscles. The deltoid muscle is large and
covers the entire surface of the shoulder, and contributes to arm movement in any
plane. The teres minor muscle is a lateral rotator and a member of the rotator cuff
group of muscles. The radial nerve arises from the posterior cord of the brachial
plexus. It is the largest branch, and it innervates the triceps brachii and anconeus
muscles in the arm. The spinal accessory nerve is cranial nerve XI, and innervates
the trapezius muscle, which elevates and depresses the scapula. The ulnar nerve
arises from the medial cord of the brachial plexus and runs down the medial aspect
of the arm. It innervates muscles of the forearm and hand.
3 A 48-year-old female court stenographer is admitted to the orthopedic clinic with
symptoms of carpal tunnel syndrome, with which she has suffered with for almost a
year. Which muscles most typically become weakened in this condition?
A. Dorsal interossei
,B. Lumbricals III and IV
C. Thenar
D. Palmar interossei
E. Hypothenar - answer- C. The thenar muscles (and lumbricals I and II) are
innervated by the median nerve, which runs through the carpal tunnel. The carpal
tunnel is formed anteriorly by the flexor retinaculum and posteriorly by the carpal
bones. Carpal tunnel syndrome is caused by a compression of the median nerve,
due to reduced space in the carpal tunnel. The carpal tunnel contains the tendons of
flexor pollicis longus, flexor digitorum profundus, and flexor digitorum superficialis
muscles and their synovial sheaths. The dorsal interossei, lumbricals III and IV ,
palmar interossei, and hypothenar muscles are all innervated by the ulnar nerve.
GAS 798, 808; N 452; McM 159
4 A 45-year-old man arrived at the emergency department with injuries to his left
elbow after he fell in a bicycle race. Plain radiographic and magnetic resonance
imaging (MRI) examinations show a fracture of the medial epicondyle and an injured
ulnar nerve. Which of the following muscles will most likely be paralyzed?
A. Flexor digitorum superficialis
B. Biceps brachii
C. Brachioradialis
D. Flexor carpi ulnaris
E. Supinator - answer- D. Fracture of the medial epicondyle often causes damage to
the ulnar nerve due to its position in the groove behind the epicondyle. The ulnar
nerve innervates one and a half muscles in the forearm, the flexor carpi ulnaris and
the medial half of the flexor digitorum profundus muscles. The nerve continues on to
innervate most of the muscles in the hand. The flexor digitorum superficialis is
innervated by the median nerve and the biceps brachii muscle by the
musculocutaneous. The radial nerve innervates both the brachioradialis and
supinator muscles.
5 While walking to his classroom building, a first year medical student slipped on the
wet pavement and fell against the curb, injuring his right arm. Radiographic images
showed a midshaft fracture of the humerus. Which pair of structures was most likely
injured at the fracture site?
A. Median nerve and brachial artery
B. Axillary nerve and posterior circumflex humeral artery
C. Radial nerve and deep brachial artery
D. Suprascapular nerve and artery
E. Long thoracic nerve and lateral thoracic artery - answer- C. A midshaft humeral
fracture can result in injury to the radial nerve and deep brachial artery because they
lie in the spiral groove located in the midshaft. Injury to the median nerve and
brachial artery can be caused by a supracondylar fracture that occurs by falling on
an outstretched hand and partially flexed elbow. A fracture of the surgical neck of the
humerus can injure the axillary nerve and posterior circumflex humeral artery. The
suprascapular artery and nerve can be injured in a shoulder dislocation. The long
thoracic nerve and lateral thoracic artery may be damaged during a mastectomy
procedure.
6 An 18-year-old man is brought to the emergency department after an injury while
playing rugby. Imaging reveals a transverse fracture of the humerus about 1 inch
,proximal to the epicondyles. Which nerve is most frequently injured by the jagged
edges of the broken bone at this location?
A. Axillary
B. Median
C. Musculocutaneous
D. Radial
E. Ulnar - answer- B. A supracondylar fracture often results in injury to the median
nerve. The course of the median nerve is anterolateral, and at the elbow it lies
medial to the brachial artery on the brachialis muscle. The axillary nerve passes
posteriorly through the quadrangular space, accompanied by the posterior circumflex
humeral artery, and winds around the surgical neck of the humerus. Injury to the
surgical neck may damage the axillary nerve. The musculocutaneous nerve pierces
the coracobrachialis muscle and descends between the biceps brachii and brachialis
muscle. It continues into the forearm as the lateral antebrachial cutaneous nerve.
The ulnar nerve descends behind the medial epicondyle in its groove and is easily
injured and produces "funny bone" symptoms.
7 A 52-year-old female band director suffered problems in her right arm several days
after strenuous field exercises for a major athletic tournament. Examination in the
orthopedic clinic reveals wrist drop and weakness of grasp but normal extension of
the elbow joint. There is no loss of sensation in the affected limb. Which nerve was
most likely affected?
A. Ulnar
B. Anterior interosseous
C. Posterior interosseous
D. Median
E. Superficial radial - answer- C. The radial nerve descends posteriorly between the
long and lateral heads of the triceps brachii muscle and passes inferolaterally on the
back of the humerus between the medial and lateral heads of the triceps brachii
muscle. It eventually enters the anterior compartment and descends to enter the
cubital fossa, where it divides into superficial and deep branches. The deep branch
of the radial nerve winds laterally around the radius and runs between the two heads
of the supinator muscle and continues as the posterior interosseous nerve,
innervating extensor muscles of the forearm. Because this injury does not result in
loss of sensation over the skin of the upper limb, it is likely that the superficial branch
of the radial nerve is not injured. If the radial nerve were injured very proximally, the
woman would not be able to extend her elbow. The branches of the radial nerve to
the triceps brachii muscle arise proximal to where the nerve runs in the spiral groove.
The anterior interosseous nerve arises from the median nerve and supplies the
flexor digitorum profundus, flexor pollicis longus, and pronator quadratus muscles,
none of which seem to be injured in this example. Injury to the median nerve causes
a characteristic flattening (atrophy) of the thenar eminence.
8 A 32-year-old woman is admitted to the emergency department after an
automobile collision. Radiologic examination reveals multiple fractures of the
humerus. Flexion and supination of the forearm are severely weakened. She also
has loss of sensation on the lateral surface of the forearm. Which of the following
nerves has most likely been injured?
A. Radial
B. Musculocutaneous
, C. Median
D. Lateral cord of brachial plexus
E. Lateral cutaneous nerve of the forearm - answer- B. The musculocutaneous nerve
supplies the biceps brachii and brachialis muscles, which are the flexors of the
forearm at the elbow. The musculocutaneous nerve continues as the lateral
antebrachial cutaneous nerve, which supplies sensation to the lateral side of the
forearm (with the forearm in the anatomic position). The biceps brachii muscle is the
most powerful supinator muscle. Injury to this nerve would result in weakness of
supination and forearm flexion and lateral forearm sensory loss. Injury to the radial
nerve would result in weakened extension and a characteristic wrist drop. Injury to
the median nerve causes paralysis of flexor digitorum superficialis muscle and other
flexors in the forearm and results in a characteristic flattening of the thenar
eminence. The lateral cord of the brachial plexus gives origin both to the
musculocutaneous and lateral pectoral nerves. There is no indication of pectoral
paralysis or weakness. Injury to the lateral cord can result in weakened flexion and
supination in the forearm, and weakened adduction and medial rotation of the arm.
The lateral cutaneous nerve of the forearm is a branch of the musculocutaneous
nerve and does not supply any motor innervation. Injury to the musculocutaneous
nerve alone is unusual but can follow penetrating injuries.
9 A 24-year-old female medical student was bitten at the base of her thumb by her
dog. The wound became infected and the infection spread into the radial bursa. The
tendon(s) of which muscle will most likely be affected?
A. Flexor digitorum profundus
B. Flexor digitorum superficialis
C. Flexor pollicis longus
D. Flexor carpi radialis
E. Flexor pollicis brevis - answer- C. Tenosynovitis can be due to an infection of the
synovial sheaths of the digits. Tenosynovitis in the thumb may spread through the
synovial sheath of the flexor pollicis longus tendon, also known as the radial bursa.
The tendons of the flexor digitorum superficialis and profundus muscles are
enveloped in the common synovial flexor sheath or ulnar bursa. Neither the flexor
carpi radialis nor flexor pollicis brevis tendons are contained in synovial flexor
sheaths.
10 Laboratory studies in the outpatient clinic on a 24-year-old woman included
assessment of circulating blood chemistry. Which of the following arteries is most
likely at risk during venipuncture at the cubital fossa?
A. Brachial
B. Common interosseous
C. Ulnar
D. Anterior interosseous
E. Radial - answer- A. The three chief contents of the cubital fossa are the biceps
brachii tendon, brachial artery, and median nerve (lateral to medial). The common
and anterior interosseous arteries arise distal to the cubital fossa; the ulnar and
radial arteries are the result of the bifurcation of the brachial artery distal to the
cubital fossa.
