1
BRS: Upper Limb Questions with 100%
Correct Answers | for Specific Exam
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1. A 21-year-old patient has a lesion of the upper trunk of
the brachial plexus (Erb- Duchenne paralysis). Which of
the following is the most likely diagnosis?
(A) Paralysis of the rhomboid major
(B) Inability to elevate the arm above the
horizontal
(C) Arm tending to lie in medial rotation
(D) Loss of sensation on the medial side of
the arm
(E) Inability to adduct the thumb
:
vPretest - Stuvia US
,2
Ans: 1. The answer is C. A lesion of the upper trunk of the
brachial plexus results in a condition called "waiter's tip
hand," in which the arm tends to lie in medial rotation
because of paralysis of lateral rotators and abductors of
the arm. The long thoracic nerve, which arises from the
root (C5-C7) of the brachial plexus, innervates the serratus
anterior muscle that can elevate the arm above the
horizontal. The dorsal scapular nerve, which arises from
the root (C5), innervates the rhomboid major. The medial
side of the arm receives cutaneous innervation from the
medial brachial cutaneous nerve of the medial cord. The
adductor pollicis is innervated by the ulnar nerve.
2. A patient comes in with a gunshot wound and requires
surgery in which his thoracoac- romial trunk needs to be
ligated. Which of the following arterial branches would
main- tain normal blood flow?
(A) Acromial
(B) Pectoral
(C) Clavicular
(D) Deltoid
:
vPretest - Stuvia US
,3
(E) Superior thoracic
Ans: 2. The answer is E. The superior thoracic artery is a
direct branch of the axillary artery. The thoracoacromial
trunk has four branches: the pectoral, clavicular,
acromial, and deltoid.
3. A 29-year-old man comes in with a stab wound,
cannot raise his arm above horizon- tal, and exhibits a
condition known as "winged scapula." Which of the
following structures of the brachial plexus would most
likely be damaged?
(A) Medial cord (B) Posterior cord (C) Lower trunk (D)
Roots
(E) Upper trunk
Ans: 3. The answer is D. Winged scapula is caused by
paralysis of the serratus anterior muscle that results from
damage to the long thoracic nerve, which arises from the
roots of the brachial plexus (C5-C7).
4. A 16-year-old patient has weakness flex- ing the
metacarpophalangeal joint of the ring finger and is
:
vPretest - Stuvia US
, 4
unable to adduct the same finger. Which of the following
muscles is most likely paralyzed?
(A) Flexor digitorum profundus
(B) Extensor digitorum
(C) Lumbrical
(D) Dorsal interosseous
(E) Palmar interosseous
Ans: 4. The answer is E. The dorsal and palmar
interosseous and lumbrical muscles can flex the
metacarpophalangeal joints and extend the
interphalangeal joints. The palmar interos- seous muscles
adduct the fingers, while the dorsal interosseous muscles
abduct the fingers. The flexor digitorum profundus flexes
the distal interphalangeal (DIP) joints.
5. A 27-year-old patient presents with an inability to draw
the scapula forward and downward because of paralysis
of the pecto- ralis minor. Which of the following would
most likely be a cause of his condition?
(A) Fracture of the clavicle
:
vPretest - Stuvia US
BRS: Upper Limb Questions with 100%
Correct Answers | for Specific Exam
1. A 21-year-old patient has a lesion of the upper trunk of
the brachial plexus (Erb- Duchenne paralysis). Which of
the following is the most likely diagnosis?
(A) Paralysis of the rhomboid major
(B) Inability to elevate the arm above the
horizontal
(C) Arm tending to lie in medial rotation
(D) Loss of sensation on the medial side of
the arm
(E) Inability to adduct the thumb
:
vPretest - Stuvia US
,2
Ans: 1. The answer is C. A lesion of the upper trunk of the
brachial plexus results in a condition called "waiter's tip
hand," in which the arm tends to lie in medial rotation
because of paralysis of lateral rotators and abductors of
the arm. The long thoracic nerve, which arises from the
root (C5-C7) of the brachial plexus, innervates the serratus
anterior muscle that can elevate the arm above the
horizontal. The dorsal scapular nerve, which arises from
the root (C5), innervates the rhomboid major. The medial
side of the arm receives cutaneous innervation from the
medial brachial cutaneous nerve of the medial cord. The
adductor pollicis is innervated by the ulnar nerve.
2. A patient comes in with a gunshot wound and requires
surgery in which his thoracoac- romial trunk needs to be
ligated. Which of the following arterial branches would
main- tain normal blood flow?
(A) Acromial
(B) Pectoral
(C) Clavicular
(D) Deltoid
:
vPretest - Stuvia US
,3
(E) Superior thoracic
Ans: 2. The answer is E. The superior thoracic artery is a
direct branch of the axillary artery. The thoracoacromial
trunk has four branches: the pectoral, clavicular,
acromial, and deltoid.
3. A 29-year-old man comes in with a stab wound,
cannot raise his arm above horizon- tal, and exhibits a
condition known as "winged scapula." Which of the
following structures of the brachial plexus would most
likely be damaged?
(A) Medial cord (B) Posterior cord (C) Lower trunk (D)
Roots
(E) Upper trunk
Ans: 3. The answer is D. Winged scapula is caused by
paralysis of the serratus anterior muscle that results from
damage to the long thoracic nerve, which arises from the
roots of the brachial plexus (C5-C7).
4. A 16-year-old patient has weakness flex- ing the
metacarpophalangeal joint of the ring finger and is
:
vPretest - Stuvia US
, 4
unable to adduct the same finger. Which of the following
muscles is most likely paralyzed?
(A) Flexor digitorum profundus
(B) Extensor digitorum
(C) Lumbrical
(D) Dorsal interosseous
(E) Palmar interosseous
Ans: 4. The answer is E. The dorsal and palmar
interosseous and lumbrical muscles can flex the
metacarpophalangeal joints and extend the
interphalangeal joints. The palmar interos- seous muscles
adduct the fingers, while the dorsal interosseous muscles
abduct the fingers. The flexor digitorum profundus flexes
the distal interphalangeal (DIP) joints.
5. A 27-year-old patient presents with an inability to draw
the scapula forward and downward because of paralysis
of the pecto- ralis minor. Which of the following would
most likely be a cause of his condition?
(A) Fracture of the clavicle
:
vPretest - Stuvia US
