Upper Limb II

Question 1

As part of the investigation of a patient with left upper limb claudication, angiography is requested to visualise the aortic arch and its branches.
Which of the following arteries would you expect to see arising from the aortic arch?
(Please select 1 option)
	 The internal thoracic artery
	 The left coronary artery
	 The left subclavian artery
	 The right common carotid artery
	 The superior thyroid artery

Answer 1

The left subclavian artery

The branches of the aortic arch are the brachiocephalic artery, the left common carotid artery and the left subclavian artery.

Question 2

A 29-year-old female trips over and falls on her outstretched right hand. On examination she has tenderness on deep palpation in the anatomical snuff box.

Answer 2

Scaphoid
Scaphoid fractures usually occur following a fall onto an outstretched hand or from ‘kick-back’ when using a starting handle on machinery. There may be pain and swelling of the hand and wrist and difficulty gripping. On examination tenderness in the anatomical snuff box is suggestive of a scaphoid fracture. There may also be tenderness over the dorsal and palmar aspects of the scaphoid bone.

Question 3

A 17-year-old male has been involved in a fight. He threw a punch with his right fist and has since been complaining of pain in the medial part of his hand.

Answer 3

Fifth metacarpal
Fifth metacarpal fractures are common and typically result from punching. They can be associated with rotation deformity and angulation and this should always be assessed.

Question 4

A 46-year-old male presents following an injury to his hand whilst starting a combustion generator at work. There is pain and swelling over the radial aspect of his left wrist and he has difficulty gripping.

Answer 4

Scaphoid
Scaphoid fractures usually occur following a fall onto an outstretched hand or from ‘kick-back’ when using a starting handle on machinery. There may be pain and swelling of the hand and wrist and difficulty gripping. On examination tenderness in the anatomical snuff box is suggestive of a scaphoid fracture. There may also be tenderness over the dorsal and palmar aspects of the scaphoid bone.

Question 5

A 23-year-old rugby player dislocates his left shoulder during a match. Examination reveals a sensory deficit over the lower half of the deltoid muscle.

Answer 5

Axillary nerve
Anterior shoulder dislocation can result in injury to the axillary nerve and results in loss of sensation over a patch of skin over the lower half of the deltoid.

Question 6

A 53-year-old lady has recently had a right mastectomy and axillary clearance for breast cancer. She complains of weakness lifting her right arm. On examination you observe ‘winging’ of the right scapula.

Answer 6

Long thoracic nerve
Long thoracic nerve injury can be caused by trauma or surgical injury to the nerve in the axilla. This results in paralysis of the serratus anterior muscle and protrusion of the inferior angle of the scapula – a winged scapula. The deltoid muscle is also paralysed and there is loss of sensation over the deltoid region.

Question 7

A pregnant 30-year-old complains of numbness over the lateral part of her palm, thumb, index and middle finger.

Answer 7

Median nerve
Carpal tunnel syndrome is common in pregnancy. The median nerve becomes compressed in the carpal tunnel and may result in thenar eminence wasting, pain, and tingling in the hand, reduced sensation in the thumb and lateral two and a half fingers and weak thumb abduction.

Question 8

A 68-year-old man falls onto his outstretched hand and presents with pain in his upper arm. There is a palpable fracture of the shaft of his humerus. There is some sensory impairment on the dorsum of his hand and the patient is unable to extend his wrist.

Answer 8

Radial nerve
Fractures of the shaft of the humerus can be associated with injury to the radial nerve as it runs in the spiral groove. This typically results in wrist drop and loss of sensation over the lateral surface of the dorsum of the hand (can be variable).

Question 9

A 10-year-old boy presents with pain in his elbow following a fall. On examination you identify a pulsatile vessel immediately medial to the biceps tendon.

Answer 9

Brachial artery
The brachial artery lies between the median nerve and biceps tendon in the cubital fossa. The median nerve is medial to and the biceps tendon is lateral to the brachial artery.

Question 10

A 70-year-old male presents with epistaxis. You want to get immediate intravenous access for resuscitation. A large vessel is identified overlying the anatomical snuffbox.

Answer 10

Cephalic vein
The superficial venous drainage of the upper limb comprises the cephalic and basilic veins. These are usually linked by the median cubital vein in the cubital fossa and are common sites for venepuncture. The cephalic vein overlies the anatomical snuffbox and ascends the lateral forearm. The basilic vein ascends the medial forearm.

Question 11

You are examining the pulse of an elderly lady with palpitations. You palpate the vessel that lies at her wrist lateral to the tendon of flexor carpi radialis.

Answer 11

Radial artery
At the wrist the radial artery is palpable on the distal radius and lies lateral to the tendon of flexor carpi radialis. The ulnar nerve passes over the flexor retinaculum at the wrist lying lateral to flexor carpi ulnaris.

Question 12

You are examining the knee of a patient complaining of pain behind his knee. You identify a prominent structure forming the lateral boundary of the upper part of the popliteal fossa.

Answer 12

Biceps tendon

The popliteal fossa contains the common peroneal nerve and the tibial nerve as well as the popliteal artery and vein.

Question 13

Which muscle lies behind the first part of the axillary nerve?
(Please select 1 option)
	 Long head of biceps
	 Long head of triceps
	 Pectoralis major
	 Subscapularis
	 Teres minor

Answer 13

Subscapularis

The axillary nerve lies at first behind the axillary artery, and in front of the subscapularis, and passes downward to the lower border of that muscle.

It then winds backward, in company with the posterior humeral circumflex artery and vein, through a quadrilateral space bounded above by the subscapularis (anterior) and teres minor (posterior), below by the teres major, medially by the long head of the triceps brachii, and laterally by the surgical neck of the humerus.

It then and divides into an anterior (supplying deloid), a posterior (supplying teres minor, posterior part of deltoid and upper lateral cutaneous nerve of the arm).

Question 14

This nerve is a direct continuation of the posterior cord of the brachial plexus.
It receives contributions from C5-C8 and T1.
It exits the axilla by leaving the posterior wall, tranversing the triangular space of the arm.
Which of the following is it?
(Please select 1 option)
Axillary nerve
Long thoracic nerve
Lower subscapular nerve
Median nerve
Radial nerve

Answer 14

Radial nerve This is the correct answerThis is the correct answer
The radial nerve is the main branch of the posterior cord of the brachial plexus.

The others are the

Axillary nerve
Thoracodorsal nerve
Subscapular nerves.
The median nerve is a continuation of the medial and lateral cord.

The long thoracic nerve originates from the ventral rami of C5 to C7.

After exiting the axilla, the radial nerve descends behind the fibres of the medial head of the triceps in the posterior compartment.

It then pierces the lateral intermuscular septum at the mid-point of the arm to reach the anterior compartment, and lies between brachialis and brachioradialis.

It passes through the cubital fossa (lateral side) beneath brachioradialis, then gives off the major posterior interosseus branch and continues downwards as the superficial radial nerve.

This then descends until it reaches the back of the hand and passes superficial to the anatomical snuffbox.

Question 15

During a neurological examination of the upper limb you attempt to elicit the triceps reflex.
You place the patient’s arm across the chest, with the elbow flexed at 90°. The triceps tendon is struck with the tendon hammer.
Which nerve (and its nerve root) are you testing?
(Please select 1 option)
Median nerve C6
Median nerve C7
Radial nerve C5
Radial nerve C6
Radial nerve C7

Answer 15

Radial nerve C7 This is the correct answerThis is the correct answer
The radial nerve innervates the triceps muscle; it is primarily derived from the C7 nerve root.

The radial nerve is the motor supply to the extensor compartments of the upper limb.

The triceps muscle is the chief extensor of the forearm. Its name derives from its three heads of origin (long, lateral and medial).

It attaches into the olecranon of the ulna.

Question 16

A motorcyclist sustains a traction injury to the upper brachial plexus. This results in which one of the following?
(Please select 1 option)
Complete paralysis of pectoralis major
Erb’s palsy
Horner’s syndrome
Klumpke’s palsy
Loss of sensation on the medial aspect of the forearm

Answer 16

Erbs palsy

The upper brachial plexus roots are C5,6. These contribute to the lateral and posterior cords.

A complete paralysis of pectoralis major implies damage to all five segments of the brachial plexus and is a good guide to the extent of plexus injury.

Erb’s palsy results from injury to the upper roots. The abductors and lateral rotators of the shoulder and the supinators are paralysed so the arm hangs by the side medially, rotated and extended at the elbow (waiters’ tip position).

Klumpke’s palsy results from damage to the lowest roots; the small muscles of the hand are usually affected, resulting in clawing of the hand.

The lateral cutaneous nerve is formed by the musculocutaneous nerve as it pierces the deep fascia at the elbow crease.

Question 17

Which of the following is a branch of the lateral cord of the brachial plexus?
(Please select 1 option)
	 Lower subscapular nerve
	 Medial pectoral nerve
	 Musculocutaneous nerve
	 Suprascapular nerve
	 Upper subscapular nerve

Answer 17

Musculocutaneous nerve

The suprascapular nerve arises from the upper trunk of the plexus.

The upper and lower subscapular nerves arise from the posterior cord of the plexus.

The medial pectoral nerve arises from the medial cord of the plexus.

Question 18

In the hand, which of the following is correct?
(Please select 1 option)
Digital nerves lie on median plane of fingers
Dislocation of lunate bone may compress ulnar nerve
Opposition of thumb tests opponens pollicis
Palmar aponeurosis attaches to subcutaneous fat
Ulnar bursa communicates with wrist joint

Answer 18

Opposition of thumb tests opponens pollicis

The digital nerves run laterally along the fingers, hence finger blocks are achieved by injecting local anaesthetic along the sides of the fingers.

Dislocation of the lunate is the commonest of all carpal dislocations, and a missed diagnosis may result in a median nerve palsy.

The principal action of opponens pollicis is opposition of the thumb (pulls thumb medially and forward across the palm).

The palmar aponeurosis is attached firmly to the overlying skin, the result of which improves the grip and protects the underlying tendons.

The ulnar bursa (synovial sheath of the profundus and superficialis tendons) does not communicate with the wrist joint.

Question 19

Which of the following is untrue in upper limb neurology?
(Please select 1 option)
In carpal tunnel syndrome (CTS) sensation is preserved over hypothenar eminence
Median nerve supplies muscles in the hand
Musculocutaneous nerve is sensory to forearm
Traction injury of T1 results in wrist drop
Ulnar nerve is sensory to forearm

Answer 19

Ulnar nerve is sensory to forearm This is the correct answerThis is the correct answer
All the muscles of the hand are supplied by the ulnar nerve, with the exception of the two lateral lumbricals, opponens pollicis, abductor pollicis brevis and flexor pollicis brevis (LOAF), all supplied by median.

Sensory loss along the lateral side of the forearm occurs in musculocutaneous nerve injury. The ulnar nerve gives no sensory innervation in the forearm. The ulnar is sensory to the medial third of the hand and one and a half fingers.

Wrist drop may occur with a traction injury which typically affects the brachial plexus (see ‘Burner’ syndrome).

The ulnar nerve passes superficial to the flexor retinaculum, hence in CTS, sensation to the hypothenar eminence is preserved.

Question 20

Which of the following regarding the forearm and at the wrist is untrue?
(Please select 1 option)
At the wrist the ulnar nerve is medial to ulnar artery
In cubital fossa median nerve is lateral to brachial artery
Median nerve supplies most of superficial forearm flexor muscles
Scaphoid and lunate articulate with radius
The superior radioulnar joint communicates with the elbow joint

Answer 20

In cubital fossa median nerve is lateral to brachial artery

At the level of the wrist the ulnar nerve lies medial to the ulnar artery, both of which pass superficial to the flexor retinaculum.

The median nerve is derived from the medial and lateral cords of the brachial plexus. It supplies all the flexors of the forearm with the exception of flexor carpi ulnaris and the medial half of flexor digitorum profundus (ulnar nerve). The median nerve is the most medial structure in the cubital fossa (followed by bifurcation of brachial artery, biceps tendon, and the radial nerve most laterally).

The styloid process of the radius has an inferior articular surface divided by a ridge - the medial part articulating with lunate and the lateral part with scaphoid.

The proximal (or superior) radioulnar joint communicates with the elbow joint, unlike the distal radioulnar joint.

Question 21

In the arm, which of the following is true?
(Please select 1 option)
Abduction of shoulder would be lost in T1 root lesions
Biceps brachii pronates and flexes
Midshaft humeral fractures may damage the ulnar nerve
The brachial artery may be palpated just medial to the biceps muscle
The profunda brachii artery is closely related to the surgical neck of humerus

Answer 21

The brachial artery may be palpated just medial to the biceps muscle

Abduction of the shoulder is lost in upper brachial plexus lesions not lower (T1).

The principal function of biceps brachii is as a supinator of the forearm and flexor of the elbow joint (it is also a weak flexor of the shoulder joint).

Mid humeral fractures damage the radial nerve.

The brachial artery is easily palpable in the antecubital fossa, lying just medial to the tendon of the biceps.

The profunda brachii arises from the near to the origin of the brachial artery, however, the brachial artery arises as a continuation of the axillary artery at the lower border of the teres minor which is distal to the surgical neck of humerus.

Question 22

In the upper limb, which of the following is correct?
(Please select 1 option)
Proximal humeral epiphyses fuse at 12 years
Proximal radioulnar joint does not communicate with the elbow joint
Section of the radial nerve in the radial groove is likely to lead to marked weakness of extension of the elbow joint
The ulnar artery is the main supply of the forearm
Upper trunk lesions of the brachial plexus will affect abduction of the fingers

Answer 22

The ulnar artery is the main supply of the forearm

The proximal humeral epiphysis fuses earlier in girls (15 years) than in boys (17 years).

Unlike the distal radioulnar joint (which does not communicate with the wrist joint), the proximal radioulnar joint communicates with the elbow joint.

Extension of the elbow is only affected with very high lesions of the radial nerve in the axilla resulting in paralysis of the triceps, anconeus and the long extensors of the wrist. Section of the nerve in the radial groove results in wrist drop and sensory loss on the back of the hand at the base of the thumb.

The main supply of the forearm is the ulnar artery which terminates (after crossing superficial to the flexor retinaculum) by joining the superficial palmar arch of the radial artery.

Abduction of the fingers (by the action dorsal interossei) is achieved via the deep branch of the ulnar nerve derived from the lower trunk of the brachial plexus.

Question 23

Which of the following statements regarding the shoulder joint is incorrect?
(Please select 1 option)
It is one of the most commonly dislocated joints
Stability of the joint is related to the short muscles of the rotator cuff
The capsule extends down onto the diaphysis of the medial aspect of the neck of the humerus
The axillary nerve may be damaged in dislocation of the shoulderjoint
The humeral head is likely to dislocate inferiorly

Answer 23

The humeral head is likely to dislocate inferiorly This is the correct answerThis is the correct answer
The shoulder joint capsule extends down onto the diaphysis of the medial aspect of the neck of humerus.

Ligaments connect the bones of the shoulder, and tendons join the bones to surrounding muscles. The biceps tendon attaches the biceps muscle to the shoulder and helps to stabilise the joint.

The shoulder joint is one of the more commonly dislocated joints of the body. Anterior shoulder dislocation occurs more frequently than posterior dislocation.

Four short muscles originate on the scapula and pass around the shoulder where their tendons fuse together to form the rotator cuff.

Anterior dislocation of the shoulder is a recognised cause of axillary nerve injury.

Question 24

Which one of the following is a rotator cuff muscle?
(Please select 1 option)
	 Deltoid
	 Latissimus dorsi
	 Rhomboid minor
	 Subscapularis
	 Teres major

Answer 24

Subscapularis

The four muscles which form the rotator cuff are

Supraspinatus
Infraspinatus
Teres minor
Subscapularis.
The tone of these muscles assists in holding the head of the humerus in the glenoid cavity during shoulder movements, thus stabilising it.

The cuff is deficient inferiorly, and this is a site of potential weakness.

Question 25

Which of the following is true regarding the radial nerve? (Please select 1 option) Arises from the upper and middle trunks of the brachial plexus Gives off a branch that is immediately related to the neck of the radius May be damaged by fractures of the midshaft of the ulna Supplies sensation to the medial side of dorsum of hand Supplies the flexor muscles of the forearm

Answer 25

Gives off a branch that is immediately related to the neck of the radius The radial nerve (C5-8) is the main branch of the posterior cord of the brachial plexus. Its motor function is to the extensor muscles of the forearm, wrist, finger and thumb. The sensory supply is to the lateral aspect of the dorsum of the hand. The sensation to the medial side of the dorsum of the hand is supplied by the ulnar nerve. It may be damaged by fractures of the humerus, causing wrist drop. The axillary nerve (C5/6) is the smaller terminal branch and supplies both the teres major and deltoid muscle. If trauma occurs in the axilla, there is atrophy of triceps with inability to extend elbow, wrist or digits.

Question 26

Which of the following statements regarding the anatomy of the hand is true? (Please select 1 option) Contraction of the palmar interossei results in abduction The anatomical snuff box is bounded by extensor pollicis brevis posteriorly The insertion of the flexor digitorum profundus muscle is into the distal phalanx The insertion of the palmaris longus muscle is into the middle phalanx The tendons of flexor digitorum superficialis muscle give attachment to the lumbrical muscles in the hand

Answer 26

The insertion of the flexor digitorum profundus muscle is into the distal phalanx Contraction of the palmar interossei results in adduction while contraction of the dorsal interossei results in abduction. In the palm the four tendons of flexor digitorum superficialis split and encircle the corresponding tendon of flexor digitorum profundus to insert into the sides of the middle phalanx. The four tendons of flexor digitorum profundus insert into the palmar surface of the base of the terminal phalanx. The tendons of flexor digitorum profundus muscle give attachment to the lumbrical muscles. Palmaris longus muscle inserts into the central part of the flexor retinaculum and lower part of the palmar aponeurosis. The anatomical snuff box is bounded by extensor pollicis brevis and abductor pollicis longus anteriorly and by extensor pollicis longus posteriorly.

Question 27

Which of the following statements regarding the nerve supply of the hand is true? (Please select 1 option) Adductor pollicis is supplied by the radial nerve Flexor carpi ulnaris is supplied by the median nerve The four lumbricals are supplied by the median nerve The median nerve supplies the palmar side of the first to third digits The ulnar nerve supplies the first and second digits

Answer 27

The median nerve supplies the palmar side of the first to third digits The ulnar nerve in the forearm gives off the dorsal cutaneous branch which divides into digital branches which supply the ulnar half of the dorsum of the hand and the medial 2 ½ fingers (that is, the third, fourth and fifth fingers) as far as the distal interphalangeal joints. In the hand the ulnar nerve divides into the superficial terminal branch which divides into the palmar digital nerves which supply the palmar surface of the medial 1 ½ fingers. Adductor pollicis is supplied by the deep branch of the ulnar nerve. Flexor carpi ulnaris is supplied by two to four branches of the ulnar nerve. In the hand the median nerve gives off the palmar digital nerves which supply the lateral 3 ½ digits. The lateral two lumbricals are supplied by the palmar digital nerves of the median nerve while the medial two lumbricals are supplied by the deep terminal branch of the ulnar nerve.

Question 28

Which of the following is correct regarding the anatomical relations of the first rib? (Please select 1 option) Subclavius attaches to the upper surface The costoclavicular ligament attaches to the tubercle The insertion of scalenus medius separates the subclavian vein and artery The subclavian vein passes posteriorly to the subclavian artery The upper trunk of the brachial plexus grooves the upper surface

Answer 28

Subclavius attaches to the upper surface The first rib is short, wide, flattened, and lies in an oblique plane. The lower surface is smooth and lies on the pleura. A small scalene tubercle on its medial border marks the attachment of scalenus anterior. On the upper surface the tubercle separates an anterior groove for the subclavian vein and a posterior groove for the subclavian artery and lower trunk of the brachial plexus. Scalenus medius is attached to a roughened area behind the artery. Anteriorly the upper surface gives attachment to the subclavius muscle and costoclavicular ligament.

Question 29

Which of the following is not true of the forearm and hand? (Please select 1 option) In the cubital fossa the median nerve is medial to the brachial artery The common flexor synovial sheath (ulnar bursa) normally extends into the index finger The dorsal cutaneous branch of ulnar nerve is given off in the forearm The scaphoid and lunate articulate with the radius Wasting of the thenar muscles may occur in carpal tunnel syndrome

Answer 29

The common flexor synovial sheath (ulnar bursa) normally extends into the index finger The median nerve is the most medial structure in the cubital fossa (followed by bifurcation of brachial artery, biceps tendon, and the radial nerve most laterally). The distal end of the radius (styloid process) articulates medially with the round head of ulna. The ulnar bursa is the common synovial sheath of both superficialis and profunda tendons and ends at the level of the bases of the distal phalanges. The dorsal cutaneous branch of the ulnar nerve is given off in the forearm and passes superficial to the extensor retinaculum in the wrist. The styloid process has an inferior articular surface divided by a ridge - the medial part articulating with lunate and the lateral part with scaphoid. Compression of the median nerve occurring in carpal tunnel syndrome may result in wasting of the thenar muscles, as they are supplied by the median nerve although there is no paraesthesia over the thenar eminence as the skin is supplied by the palmar cutaneous branch passing superficial to flexor retinaculum.

Question 30

Which of the following is true regarding the brachial plexus? (Please select 1 option) After emerging from the intervertebral foramina, the plexus roots lie anterior to scalenus anterior Each of the three trunks divides into two cords at the lateral edge of the first rib It is formed from the anterior rami of the second to fifth cervical roots The cords form the terminal branches The plexus lies within a sheath which starts where the plexus passes under the clavicle

Answer 30

The cords form the terminal branches The brachial plexus is formed from the anterior primary rami of the fifth cervical to the first thoracic nerve roots. After emerging from the intervertebral foramina, the plexus roots are located between the scalene muscles and at the lateral edge of the first rib each trunk divides into two divisions (not cords). The three cords divide into the terminal branches: ``` Radial nerve Median nerve Ulnar nerve Musculocutaneous nerve. The brachial plexus lies within a sheath which is a tube of fibrous tissue, and is enclosed over its entire length from the cervical vertebrae to the distal axilla. ```

Question 31

In the axilla, which of the following is correct? (Please select 1 option) If the thoracodorsal nerve is divided in an axillary dissection the patient will have winging of the scapula Level 3 lymph nodes are lateral to the pectoralis minor The cords of the brachial plexus surround the first part of the axillary artery The intercostobrachial nerve is commonly divided in axillary dissection The subscapular artery is a branch of the third part of axillary artery

Answer 31

The subscapular artery is a branch of the third part of axillary artery This is the correct answerThis is the correct answer The subscapular artery is the largest branch of the axillary artery, coming off from the third part. The other branches are: ``` The superior thoracic Thoraco-acromial Lateral thoracic Anterior Posterior circumflex humeral. Level 1 nodes lie lateral to pectoralis minor, level 2 behind and level 3 medial to the pectoralis minor. ``` The intercostobrachial nerve may be divided during axillary dissection, resulting in the patient complaining of an area of paraesthesia over the medial aspect of the inner upper arm. If the long thoracic nerve is divided, a winged scapula will result (nerve supply to serratus anterior), but if the thoracodorsal nerve is divided (nerve supply to latissimus dorsi) there will be weakness of shoulder adduction. The cords of the brachial plexus surround the second part of the axillary artery and this is how they derive their names, that is, lateral, posterior and medial cords, due to this anatomical relationship with the artery.

Question 32

Which of the following is not a branch of the brachial plexus? (Please select 1 option) Intercostobrachial nerve Lateral pectoral nerve Long thoracic nerve Medial brachial cutaneous nerve of the arm Medial pectoral nerve

Answer 32

Intercostobrachial The intercostobrachial nerve represents the lateral cutaneous branch of the second intercostal nerve. It forms a loop and runs with the medial brachial cutaneous nerve, together supplying sensory innervation of the medial aspect of the arm as far as the elbow. All the others represent infraclavicular branches of the brachial plexus, except the long thoracic which is a supraclavicular branch.

Question 33

Which of the following statements is true of the musculocutaneous nerve? (Please select 1 option) Contains only sensory fibres Is a branch of the lateral cord of the brachial plexus Leaves the plexus at the point at which it crosses the first rib None of the above is correct Receives fibres from the eighth cervical spinal root

Answer 33

Is a branch of the lateral cord of the brachial plexus The musculocutaneous nerve is the major terminal branch of the lateral cord of the brachial plexus. The lateral cord contains fibres from the superior and middle trunks which represent the spinal roots of the fifth to seventh cervical vertebrae. It leaves the plexus as the cords give off their branches to the major nerves of the arm. The cords correspond to the point at which the plexus emerges from behind the clavicle. It courses the axilla in the coracobrachialis muscle, and then descends obliquely and laterally between the biceps and brachialis muscles, sending motor fibres to all of these. It terminates in the forearm as the lateral antebrachial cutaneous nerve supplying sensation to the lateral aspect of the forearm.

Question 34

Which of the following is not true of the intercostal nerves? (Please select 1 option) Anteriorly they run in the costal groove on the lower margin of the rib Each is connected to a ganglion of the sympathetic trunk The twelfth intercostal nerve is also known as the subcostal nerve They innervate the pectoralis major They represent the ventral rami of the thoracic spinal nerves

Answer 34

They innervate the pectoralis major The intercostal nerves represent the ventral rami of the first eleven thoracic spinal nerves. The twelfth, being below the twelfth rib is subcostal, hence is called the subcostal nerve. Each intercostal nerve is connected to a ganglion of the sympathetic trunk by rami communicantes, to and from which they carry preganglionic and postganglionic fibres which innervate blood vessels, sweat glands, and muscles.

Question 35

Regarding the scaphoid, which of the following is correct? (Please select 1 option) Gives an attachment to the extensor retinaculum Has a tubercle which is palpated in the anatomical snuff box (ASB) Has an arterial supply which enters the bone proximally Is one of the bones constituting the ulnocarpal joint Is the least commonly fractured carpal bone

Answer 35

Has a tubercle which is palpated in the anatomical snuff box (ASB) The arterial supply to the scaphoid is from both proximal and distal directions, although it can be the case that the supply is from the distal end solely. In this case, fracture of the scaphoid through the neck (the scaphoid is the most commonly fractured carpal bone) may result in avascular necrosis of the proximal fragment if left untreated. The flexor retinaculum is attached laterally to the tubercle of the scaphoid (which is palpated in the ASB) and also to the trapezium. The radiocarpal joint is made up of the distal radius together with the scaphoid, lunate and triquetral.

Question 36

Which of the following is not true of the upper limb? (Please select 1 option) The hypothenar muscles are supplied by the ulnar nerve The medial part of the forearm is supplied by T1 The small muscles of the hand are supplied by T3 The superficial palmar arch lies lateral to the hook of the hamate The trapezium articulates with the first metacarpal

Answer 36

The small muscles of the hand are supplied by T3 The dermatomes for C8, T1 and T2 lie along the medial border of the upper limb, with the medial part of the forearm being supplied by T1. The muscles of the hand are supplied by either the ulnar (C8-T1) or the median nerve (C5-T1), with the hypothenar eminence being supplied solely by the ulnar nerve. The superficial palmar arch is a direct continuation of the ulnar artery and lies lateral to the hook of hamate. As the artery enters the palm it curves laterally behind the palmar aponeurosis and superficial to the flexor tendons. The trapezium articulates (via a synovial saddle shaped joint) with the base of the first metacarpal to form the carpometacarpal joint of the thumb.

Question 37

Which of the following is correct in the forearm and hand? (Please select 1 option) Flexor digitorum superficialis flexes the distal interphalangeal joint T1 traction produces a claw hand The deep ulnar nerve supplies all lumbricals The radial nerve supplies all sensation to the thumb, index and middle fingers The ulna articulates with triquetral

Answer 37

T1 traction produces a claw hand The radial nerve T1 root supplies the intrinsic muscles of the hand. Upward traction (classically during a breech delivery) on T1 causes a claw hand (Klumpke's paralysis). Flexor digitorum profundus (FDP) flexes the distal interphalangeal (IP) joint. The deep ulnar nerve supplies the third and fourth lumbricals only (median to lateral two lumbricals). The radial nerve via the superficial branch of the radial nerve provides sensory innervation to much of the back of the hand, including the proximal thumb, index finger and lateral middle finger plus the web of skin between the thumb and index finger. There is considerable overlap with the cutaneous branches of the median and ulnar nerves. The wrist joint (or radiocarpal joint) is formed between the scaphoid, lunate and triquetral bones and the distal radius.

Question 38

At the shoulder joint, which of the following is correct? (Please select 1 option) Capsule is poorly supported posteriorly Post dislocation of shoulder joint is commonest type of dislocation Section of the nerve related to surgical neck of humerus would paralyse teres minor muscle Subacromial bursa communicates with the shoulder joint cavity Triceps tendon is intracapsular

Answer 38

Section of the nerve related to surgical neck of humerus would paralyse teres minor muscle The shoulder is the commonest joint for dislocation to occur but posterior dislocation is rare. The shoulder joint is unstable due to the fact that the glenoid cavity is shallow and the surrounding ligaments are weak. The stability of the joint is achieved by the integrity of the surrounding muscles, that is, rotator cuff. The least supported part of the joint is inferiorly. The axillary nerve (supplying teres minor) passes around the surgical neck of the humerus, hence section would paralyse teres minor. The subacromial bursa does not communicate with the shoulder cavity. The triceps has three heads: ``` Long head (from the infraglenoid tubercle of the scapula) Lateral head (from upper half of posterior surface of shaft of humerus) Medial head (from posterior surface of lower half of shaft of the humerus below the spiral groove). The common tendon, which is not intracapsular, inserts into the olecranon process of ulna ```

Question 39

Which of the following concerning the thumb and thenar eminence is untrue? (Please select 1 option) 1st metacarpal articulates with trapezoid Dorsal cutaneous branch of ulnar nerve is given off in forearm Scaphoid may be palpated in anatomical snuffbox Synovial sheath of flexor pollicis longus communicates with radial bursa Wasting of thenar muscles may occur as a result of carpal tunnel syndrome

Answer 39

1st metacarpal articulates with trapezoid The ulnar nerve enters the forearm by passing around the medial epicondyle. In the distal third of the forearm the palmar and posterior (dorsal) cutaneous branch is given off. The trapezium articulates with the first metacarpal. The scaphoid is palpable in the anatomical snuffbox, hence ASB tenderness is indicative of scaphoid fracture. The radial bursa is the synovial sheath of the flexor pollicis longus, and communicates with the ulnar bursa (synovial sheath of the profundus and superficialis tendons) in half of patients. The thenar muscles are supplied by the median nerve which passes deep to the flexor retinaculum and hence is compressed in carpal tunnel syndrome.

Question 40

``` Which of the following provide sensory innervation to the palmar aspect of the ring finger? (Please select 1 option) Posterior musculocutaneous nerve Radial nerve Recurrent branch of the median nerve Superficial branch of the radial nerve Ulnar nerve ```

Answer 40

Ulnar nerve This is the correct answerThis is the correct answer The medial half of the ring finger is supplied by the ulnar nerve and the lateral half by the median nerve.