1- Upper limb Flashcards
(1-601) A 10 year old boy is admitted to the emergency department following a fall. On examination, there is deformity and swelling of the forearm. The ability to flex the fingers of the affected limb is impaired. However, there is no sensory impairment. Imaging confirms a displaced forearm fracture. Which of the nerves listed below is likely to have been affected?
Anterior interosseous nerve
Forearm fractures may be complicated by neurovascular compromise. The anterior interosseous nerve may be affected. It has no sensory supply so the defect is motor alone.
(1-601/A) What is the anterior interosseous nerve?
A branch of the median nerve that supplies the deep muscles on the front of the forearm, except the ulnar half of the flexor digitorum profundus.
(1-601/B) Where does the anterior interosseous nerve travel?
It accompanies the anterior interosseous artery along the anterior of the interosseous membrane of the forearm, in the interval between the flexor pollicis longus and flexor digitorum profundus.
(1-601/C) What muscles does the anterior interosseous nerve innervate?
It innervates the flexor pollicis longus, pronator quadratus, and the radial half of the flexor digitorum profundus (the lateral two out of the four tendons).
(1-601/D) Where does the anterior interosseous nerve end?
It ends below in the pronator quadratus and the wrist joint.
(2 - 601)
Which of the following nerves supplies the skin on the palmar aspect of the thumb?
Median
The median nerve supplies cutaneous sensation to this region.
(2- 601/ A) How is the median nerve formed?
t is formed by the union of a lateral and medial root from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus.
(2- 601/ B) What is the path of the median nerve in the upper arm?
It descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery) and passes deep to the bicipital aponeurosis and the median cubital vein at the elbow.
(2- 601/ C)What is the path of the median nerve in the forearm?
It passes between the two heads of the pronator teres muscle and runs on the deep surface of flexor digitorum superficialis (within its fascial sheath). Near the wrist, it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to the palmaris longus tendon. It then passes deep to the flexor retinaculum to enter the palm, but lies anterior to the long flexor tendons within the carpal tunnel.
(2- 601/ D) What are the branches of the median nerve in the forearm?
The branches in the forearm include pronator teres, pronator quadratus, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, flexor pollicis longus, and the radial half of flexor digitorum profundus.
(2- 601/ E ) What is the sensory innervation of the median nerve in the hand?
It innervates the palmar aspect of the thumb and lateral 2½ fingers. On the palmar aspect, the innervation projects proximally, and on the dorsal aspect, only the distal regions are innervated with the radial nerve providing the more proximal cutaneous innervation.
(2- 601/ F ) What are some patterns of damage to the median nerve?
Damage at the wrist, such as carpal tunnel syndrome, can cause paralysis and wasting of the thenar eminence muscles and opponens pollicis (ape hand deformity), as well as sensory loss to the palmar aspect of the lateral (radial) 2½ fingers. Other symptoms may include inability to pronate the forearm, weak wrist flexion, and ulnar deviation of the wrist.
(2- 601/ G )What is the anterior interosseous nerve?
It is a branch of the median nerve that leaves just below the elbow and results in the loss of pronation of the forearm and weakness of the long flexors of the thumb and index finger.
( 7 of 601)
A 63 year old lady is undergoing an axillary sentinel lymph node biopsy as part of her breast cancer treatment. Which of the structures listed below is most likely to be encountered?
Intercostobrachial nerve
A particularly careless surgeon could encounter all of these. However, during a routine level 1 axillary exploration which is where the majority of sentinel nodes will be located, the nerves most commonly encountered are the Intercostobrachial nerves.
( 7 of 601/A )What are the boundaries of the axilla?
Medially: Chest wall and Serratus anterior;.
Laterally: Humeral head.
Floor: Subscapularis.
Anterior aspect: Lateral border of Pectoralis major.
Fascia: Clavipectoral fascia
( 7 of 601/B )What is the function of the long thoracic nerve?
It supplies the serratus anterior muscle and its damage can lead to winging of the scapula.
( 7 of 601/C )What is the location of the long thoracic nerve?
It lies on the medial chest wall and passes behind the brachial plexus to enter the axilla.
( 7 of 601/D )What does the thoracodorsal nerve and thoracodorsal trunk innervate?
They innervate and vascularize the latissimus dorsi muscle.
( 7 of 601/D ) Where is the axillary vein located?
It lies at the apex of the axilla and is the continuation of the basilic vein. It becomes the subclavian vein at the outer border of the first rib.
( 7 of 601/E ) What is the function of the intercostobrachial nerves?
They provide cutaneous sensation to the axillary skin and traverse the axillary lymph nodes.
( 7 of 601/F )What is the main site of lymphatic drainage for the breast?
The axilla serves as the main site of lymphatic drainage for the breast.
(10 of 601)
A 35 year old farm labourer injures the posterior aspect of his hand with a mechanical scythe. He severs some of his extensor tendons in this injury. How many tunnels lie in the extensor retinaculum that transmit the tendons of the extensor muscles?
Six
There are six tunnels, each lined by its own synovial sheath.
(Question 12 of 601)
Which of the muscles listed below is not innervated by the median nerve?
Adductor pollicis
Adductor pollicis is innervated by the ulnar nerve.
Medial two lumbricals innervated by the ulnar nerve
( 14 of 601 )
A 23 year old man is involved in a fight outside a nightclub and sustains a laceration to his right arm. On examination, he has lost extension of the fingers in his right hand. Which of the nerves listed below is most likely to have been divided?
Radial
The radial nerve supplies the extensor muscle group
( 17 of 601 )
An injured axillary artery is ligated between the thyrocervical trunk of the subclavian and subscapular artery. Subsequent collateral circulation is likely to result in reversal of blood flow in which of the vessels listed below?
Transverse cervical artery
It is asking about the branches of the axillary artery and knowledge of the fact that there is an extensive collateral network around the shoulder joint
( 17 of 601/A )
What is the circumflex scapular artery a branch of?
It is a branch of the subscapular artery.
( 17 of 601/B )
What is the normal function of the circumflex scapular artery?
It normally supplies the muscle on the dorsal aspect of the scapula.
( 17 of 601/C )
What happens when flow is reversed in the circumflex scapular and subscapular arteries?
It forms a collateral circulation around the scapula.
( 17 of 601/D )
Where does the axillary artery extend from and to?
It extends from the outer border of the first rib to the lower border of teres major, where it becomes the brachial artery.
( 17 of 601/E )
How is the axillary artery subdivided?
It is subdivided into three parts: the first part lies above pectoralis minor, the second part is behind the muscle, and the third part lies inferior to it.
( 17 of 601/F )
What structures enclose the axillary artery and vein within the cords of the brachial plexus?
They are enclosed within the axillary sheath, which is a prolongation of the prevertebral fascia.
( 17 of 601/G )
What structures surround the axillary artery in the first part?
The axillary vein, cords of the brachial plexus, axillary sheath, clavipectoral fascia, serratus anterior, long thoracic nerve, and the medial cord of the brachial plexus.
( 17 of 601/H )
What structures surround the axillary artery in the second part?
Pectoralis minor and major, posterior cord of the brachial plexus, and the medial cord of the brachial plexus.
( 17 of 601/I )
What nerves are interspersed between the axillary artery and subscapularis muscle?
The axillary and radial nerves are interspersed between the artery and subscapularis.
( 17 of 601/J )
What nerves are located laterally to the axillary artery?
The median and musculocutaneous nerves and coracobrachialis are located laterally to the artery.
( 17 of 601/H )
What is the axillary vein related to medially?
The axillary vein is related medially to the axillary artery.
What structures surround the axillary artery in the third part?
Subscapularis, latissimus dorsi, teres major, axillary and radial nerves, medial root of the median nerve, median and musculocutaneous nerves, and coracobrachialis.
What is the relationship of the axillary vein to the axillary artery?
The axillary vein is related medially to the axillary artery.
What are the branches of the axillary artery?
1/Highest thoracic artery
2/Thoraco-acromial artery
3/Lateral thoracic artery
4/Subscapular artery
5/Posterior circumflex humeral artery
6/Anterior circumflex humeral artery
(23 of 601)
A 43 year old typist presents with pain at the dorsal aspect of the upper part of her forearm. She also complains of weakness when extending her fingers. On examination triceps and supinator are both functioning normally. There is weakness of most of the extensor muscles. However, there is no sensory deficit. Which of the following nerves has been affected?
Posterior interosseous
(23 of 601/ A)
Where can the radial nerve become entrapped?
In the arcade of Frohse
(23 of 601/ B)
What is the arcade of Frohse?
It is a superficial part of the supinator muscle that overlies the posterior interosseous nerve.
(23 of 601/ C)
What muscles does the radial nerve give branches to?
Extensor carpi radialis brevis and supinator.
(23 of 601/ D)
What path does the radial nerve take after passing postero-inferiorly?
It enters the supinator and curves around the lateral and posterior surfaces of the radius.
(23 of 601/ E)
Where does the posterior interosseous nerve lie after emerging from the supinator?
Between the superficial extensor muscles and the lowermost fibers of the supinator
(23 of 601/ F)
What muscles does the posterior interosseous nerve give branches to?
The extensors.
(23 of 601/ G)
Where does the posterior interosseous nerve emerge from?
t emerges from the supinator between the superficial extensor muscles and the lowest fibers of the supinator.
(23 of 601/ H)
What muscles does the posterior interosseous nerve innervate through recurrent branches?
Extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris.
(23 of 601/ I)
What path does the posterior interosseous nerve take after emerging from the supinator?
It passes superficial to the abductor pollicis longus along with the posterior interosseous artery.
(23 of 601/ J)
What muscle does the posterior interosseous nerve supply in this region?
It supplies the abductor pollicis longus.
(23 of 601/ K)
What muscles does the posterior interosseous nerve give branches to?
Extensor pollicis longus, extensor pollicis brevis, and extensor indicis.
(23 of 601/ L)
Where does the posterior interosseous nerve end?
It ends as a small gangliform enlargement at the back of the carpus.
(23 of 601/ M)
What is the function of the gangliform enlargement?
It supplies the intercarpal joints.
(29 of 601)
A 23 year old man falls and slips at a nightclub. A shard of glass penetrates the skin at the level of the medial epicondyle, which of the following sequelae is least likely to occur?
Claw like appearance of the hand
(29 of 601/A)
What is the typical hand deformity seen in ulnar nerve injuries in the mid to distal forearm?
Claw hand
(29 of 601/A)
What does the claw hand consist of?
Flexion of the 4th and 5th interphalangeal joints and extension of the metacarpophalangeal joints.
(29 of 601/B)
How does the clawing effect change when the flexor digitorum profundus is not affected?
The clawing is more pronounced.
(29 of 601/C)
What is the term for the milder hand deformity seen in more proximal ulnar nerve lesions?
Ulnar paradox
(29 of 601/D)
Why is it called the ulnar paradox?
Because, despite the more proximal level of transection, the hand does not have a claw-like appearance seen in distal injuries.
(29 of 601/E)
Which muscle is affected in ulnar nerve injuries that are more proximally sited?
The first dorsal interosseous muscle.
(29 of 601/F)
What is the origin of the ulnar nerve?
C8, T1
(29 of 601/G)
Which muscles does the ulnar nerve supply in the forearm?
Flexor carpi ulnaris, flexor digitorum profundus, flexor digiti minimi, abductor digiti minimi, opponens digiti minimi, adductor pollicis, interossei muscles, third and fourth lumbricals, and palmaris brevis.
no muscle in upper arm
(29 of 601/H)
What path does the ulnar nerve take from the upper arm to the palm of the hand?
Posteromedial aspect of the upper arm to the flexor compartment of the forearm, then along the ulnar.
It passes beneath the flexor carpi ulnaris muscle, then superficially through the flexor retinaculum into the palm of the hand.
(29 of 601/I)
What are the effects of ulnar nerve damage at the wrist?
Wasting and paralysis of intrinsic hand muscles (claw hand), wasting and paralysis of hypothenar muscles, and loss of sensation in the medial 1 and a half fingers.
(29 of 601/J)
What is claw hand?
It is a condition characterized by the wasting and paralysis of intrinsic hand muscles, resulting in the flexion of the 4th and 5th digits and extension of the metacarpophalangeal joints.
(29 of 601/K)
Which muscles are affected in the hypothenar region?
The hypothenar muscles, which are responsible for controlling the movement of the pinky finger and the muscles at the base of the thumb.
(29 of 601/L)
Which fingers experience a loss of sensation in ulnar nerve damage at the wrist?
The medial 1 and a half fingers, which includes the pinky finger and half of the ring finger.
(29 of 601/M)
What are the effects of ulnar nerve damage at the elbow?
Radial deviation of the wrist and less prominent clawing in the 4th and 5th digits.
(29 of 601/H)
Why is clawing less prominent in the 4th and 5th digits in ulnar nerve damage at the elbow?
Because the ulnar nerve is responsible for the flexion of these digits, and damage at the elbow affects its function to a lesser extent compared to damage at the wrist.
(31 of 601)
A 43 year old man is stabbed outside a nightclub. He suffers a transection of his median nerve just as it leaves the brachial plexus. Which of the following features is least likely to ensue?
Complete loss of wrist flexion
(31 of 601/A)
How is the median nerve formed?
It is formed by the union of a lateral and medial root respectively from the lateral (C5,6,7) and medial (C8 and T1) cords of the brachial plexus.
(31 of 601/B)
What is the path of the median nerve in the upper arm and forearm?
It descends lateral to the brachial artery, crosses to its medial side (usually passing anterior to the artery), passes deep to the bicipital aponeurosis and the median cubital vein at the elbow, and runs on the deep surface of the flexor digitorum superficialis (within its fascial sheath).
(31 of 601/C)
What is the location of the median nerve near the wrist?
It becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, deep to the palmaris longus tendon.
(31 of 601/D)
Where does the median nerve enter the palm?
It passes deep to the flexor retinaculum to enter the palm.
