Upper limb Flashcards

Question

Which is false with respect to the lateral intermuscular septum? A Pierced by radial nerve B It is the origin of medial head of triceps C Pierced by middle collateral branch of profunda brachii artery D Brachioradilais and extensor carpi radialis longus attach to the septum

Answer 1

C Explanation The septum extends along the lateral supracondylar line and fades out behind the insertion of the deltoid. Brachioradilais and extensor carpi radialis longus extend out from the humerus to gain attachment to the septum in front, and posteriorly the medial head of tricpes arises form it. It is pierced by the radial nerve and the profunda brachii artery (the radial collateral branch). The middle collateral branch of the profunda brachii artery descends in the medial head of triceps Extra: the medial intermuscular septum is pierced by the ulnar nerve and the superior ulna collateral artery. Note: in Lasts anatomy: the medial head arises from both intermuscular septa. A web search writes: The medial head arises distally from the groove of the radial neck; from the dorsal surface of the humerus; from the medial intermuscular septum; and its distal part also arises from the lateral intermuscular septum It is not clearly written in the latest textbook

Answer 2

C Explanation Proximal attachments: spinous process of the inferior 6 thoracic vertebrae, thoraco-lumbar fascia, posterior 1/3 of illiac crest, last three to four ribs and inferior angle of scapula. Insertion: floor of intertubecular groove (sulcus) of the humerus Actions: Extends the shoulder joint, internally rotates the humerus and is a powerful adductor in combination with pectoralis major. It is especially used in restoring the the upper limb from abduction above the shoulder, it is the climbing mucle Nerve supply: Thoracodorsal N C678

Answer 3

C Explanation Teres Major forms the lower border of both the quadrangular space and triangular space. It is supplied by the subscapular nerve. It arises form the infero-lateral border of the scapula

Answer 4

D Explanation The joint is supplied by the medial supraclavicular nerves of C3 and C4 form the cervical plexus. It contains only one fibrocartilaginous joint. The costoclavicular ligament is the fulcrum of movements at the joint. Stability of the joint is maintained by ligaments , especially the costoclavicular ligament. It takes all the strain off the joint, transmitting stress from he clavicle to the first costal cartilage. The costoclavicular ligament is very strong and is the major stabilising factor of the sternoclavicular joint. The current TB: The strength of the sternoclavicular joint depends on its ligaments and disc. The main strength seems to be from the anterior and posterior sternoclavicular ligaments and the interclavicular ligament. The costoclavicular ligament acts as an anchor and limits elevation. It doesn’t specify one ligament as strongest. Old question- have not changed it- see it as a learning experience.

Answer 5

B Explanation All the other muscles are only synergists. Teres major causes internal rotation of the humerus as well as adduction

Answer 6

A Explanation Joint capsule of the glenohumeral joint The inferior part of the joint capsule, the only part not reinforced by the rotator cuff muscles, is it weakest area. Here the capsule is particularly lax and lies in folds when thew arm is adducted; however, it becomes taut when the arm is abducted. Rotator cuff muscles stabilise the joint in abduction. Extra The long head of triceps is the most important factor in stabilizing the abducted shoulder joint to counteract gravity Note: in Lasts anatomy it states that the long head of triceps supports the capsule of the shoulder joint when the arm is ABDucted, and it aids in extending the shoulder joint CM: It states that the muscle action is the chief extensor of the forearm and long head resists dislocation of humerus especially important during ADDuction Extra: Note: In previous textbooks- the action of the triceps: the extensor of the elbow joint. The long head supports the capsule of the shoulder joint when the arm is ABDucted, and it aids in extending the shoulder joint. This is wrong In the prescribed text: chief extensor of the forearm. The triceps brachii is a large fusiform muscle in the posterior compartment of the arm. As indicated by its name, the triceps has three heads: long, lateral, and medial. The triceps is the main extensor of the forearm. Because its long head crosses the glenohumeral joint, the triceps helps stabilize the aDDucted glenohumeral joint by serving as a shunt muscle, resisting inferior displacement of the head of the humerus. The long head also aids in extension and adduction of the arm, but it is actually the least active head. (follow the current source)

Answer 7

C Explanation Origin: The long head arises from the supraglenoid tubercle. The short head arises from the coracoid process. Insertion: Tuberosity of radius and fascia of forearm via bicipital aponeurosis. Innervation: It is supplied by the musculocutaneous nerve C567. Action: Supinate forearm, flexible forearm when in supine, short head resistance shoulder dislocation

Answer 8

B Explanation It is a continuation of the axillary artery. The median nerve lies lateral to it and then crosses over to lie medially in the cubital fossa. Its largest branch is the deep artery of the arm (L. arteria prifunda brachii). It passes anterior to the medial supraepicondylar ridge at the elbow joint

Answer 9

D Explanation The middle trunk gives rise (contributes) to the lateral cord which forms the median nerve. The middle trunk receives only the C7 nerve root (C8 is not affected). The medial cord arises only from the inferior trunk. The long thoracic nerve arises from the roots of C5-7, before the formation of the trunks.

Answer 10

B Explanation Muscles comprising the rotator cuff are: teres minor, infraspinatus, suraspinatus and subscapularis. The rotator cuff is the group of muscles and their tendons that act to stabilize the shoulder. The four muscles of the rotator cuff, along with the teres major and the deltoid make up the six scapulohumeral muscles which connect to the humerus and scapula, and act on the glenohumeral joint. Note: Supraspinatus is actually the only muscle that does not rotate the humerus

Answer 11

A Explanation The contents of the fossa, from medial to lateral side are the median nerve, brachial artery, tendons of the biceps and farther laterally the radial nerve and its posterior interosseus branch. The cubital fossa is the triangular area between pronator teres, brachioradialis and a line joining the humeral epicondyles. The ulnar artery passes deep to the deep head of pronator teres. The brachial artery enters the cubital fossa in the midline. Halfway down the fossa it divides into the radial and ulnar arteries. The radial artery usually appears to be direct continuation of the brachial artery and the bigger ulnar artery branches off at an angle An easy way to remember the order of structures in the cubital fossa is: Really Need (radial nerve) Beer To (biceps tendon) Be At (brachial artery) My Nicest (median nerve). (from lateral to medial)

Answer 12

A Explanation The contents of the cubital fossa, from medial to lateral are median nerve, brachial artery, tendon of biceps bracii, radial nerve, and posterior interosseous nerve. The cubital fossa is the triangular area between pronator teres, brachioradialis and a line joining the humeral epicondyles. The ulnar artery passes deep to the deep head of pronator teres. The brachial artery enters the cubital fossa in the midline. Halfway down the fossa, it divides into the radial and ulnar arteries. The radial artery usually appears to be the direct continuation of the brachial artery, and the bigger ulnar artery branches off at an angle.

Answer 13

C Explanation The triceps is supplied by the profunda brachii artery. It has 3 heads and stabilizes the shoulder in adduction. In the prescribed text: chief extensor of the forearm. The triceps brachii is a large fusiform muscle in the posterior compartment of the arm. As indicated by its name, the triceps has three heads: long, lateral, and medial. The triceps is the main extensor of the forearm. Because its long head crosses the glenohumeral joint, the triceps helps stabilize the aDDucted glenohumeral joint by serving as a shunt muscle, resisting inferior displacement of the head of the humerus. The long head also aids in extension and adduction of the arm, but it is actually the least active head. It is supplied by the radial nerve (C6, C7, C8) The above is from the new textbook. Interesting in Last anatomy: Action of the triceps- "the muscle is the extensor of the elbow joint. The long head supports the capsule of the shoulder joint when the arm is ADBucted, and it aids in extending the shoulder joint" Note: this explanation is often queried. The statement "the triceps helps stabilize the aDDucted glenohumeral joint" is directly out of the textbook latest edition. Many users feel it should be ABDucted (as per Lasts Anatomy). Therefore, not much more can be done.

Answer 14

B Explanation Usually, the FPL is deeper to the rest of these structures. Extra: Forearm structures superficial to deep: 4x superficial flexor/pronator muscles (PT/FCR/PL/FCU) Ulnar nerve: running down between the axillary artery and vein, behind the medial cutaneous nerve of the forearm, the ulnar nerve pierces the medial intermuscular septum and descends in the groove on the back of the base of the medial epicondyle. It passes between the two heads of the FCU and enters the flexor compartment of the forearm. Median Nerve at the elbow it lies medial to the artery beneath the bicipital aponeurosis. It passes between the two heads of pronator teres and deep to the fibrous arch of flexor digitorium superficialis. Enters hand via carpal tunnel. 3x Deep flex/pronators: FDP/ FPL/ PQ. Radial artery runs lateral to FCR tendon under cover of brachioradialis and marks the boundary between the anterior and posterior compartments.

Answer 15

B Explanation The brachial plexus has 6 divisions. The nerve to subclavius arises from the trunks. The suprascapular nerve arises form the trunks. The axillary nerve is derived from the posterior cord. The 5 roots lie behind the scalenus anterior muscle and emerge between it and scalenus medius to form the trunks that cross the lower part of the posterior triangle of the neck. The divisions form behind clavicle and subclavicular, the cords in the axilla and branches in the brachium Please be aware that old sources differ from the current. The current prescribed text it says that the nerve to subclavius originates from superior trunk (not the roots). However, in older sources, it states that the nerve to subclavius is one of the three branches from the roots. The other two are dorsal scapular and long thoracic. Suprascapular nerve arises form the trunks. (Follow the current source)

Answer 16

B Explanation Flexor carpi ulnaris (FCU) tendon inserts into pisiform, pisohamate ligament, pisometacarpal ligament, hamate and 5th metacarpal bone The carpal tunnel lies between the flexor retinaculum and the carpal bones. The median nerve and the flexor tendons of the fingers and thumb pass through this tunnel. The four tendons of the superficial flexor are separate and lie in two rows, with the middle and ring finger tendons in front of the index and little finger tendons. The tendons of the flexor digitorium profundus lie deeply in one plain, with only the tendon to the index finger being separate from the others, which remain attached together till they reach the palm. All eight tendons of the superficial and deep flexors share a common tendon sheath, which does not invest them completely but is reflected from their radial sides, where arteries gain access. The tendon of flexor pollices longus lies in its own synovial sheath as it passes through the fibro-osseous tunnel. At the lateral end of the tunnel a deep lamina from the flexor retinaculum is attached to the medial lip of the grove of the trapezium. The tendon of flexor carpi radialis, enclosed in its own synovial sheath runs in the groove in this subcompartment of the carpal tunnel. The median nerve passes deep to the flexor retinaculum between the flexor digitorium superficialis tendon to the middle finger and the flexor carpi radialis tendon. The ulnar nerve lies on the front of the reticulum lateral to the pisiform bone, with the ulnar artery lateral to the nerve (in the canal of Guyon) Extra: Carpal Tunnel lies bounded by distal carpus and transverse carpal ligament. Contains 9 tendons (4x FDS, 4xFDP, 1xFPL) and 1 nerve (Median) Note that palmaris longus tendon sits superficial to ligament centrally, as do FCR and FCU laterally and medially. The ulnar artery and nerve pass through Guyon's canal superficial and lateral to transverse carpal ligament.

Answer 17

B Explanation It runs with the profunda brachii artery in the radial groove of the humerus. The radial nerve divides into the posterior interosseus (aka deep) and superficial branches at the level of the lateral epicondyle. The radial nerve contains fibres from C5-T1. Between the origins of the the medial and lateral heads of triceps, the radial nerve and profunda brachii artery lie in the radial groove.

Answer 18

A Explanation It is triangular in shape. It inserts into the lateral lip of the bicipital sulcus. The clavicular head arises from the medial surface portion of the anterior surface of the clavicle In the older TB it reads: the muscle is the only one in the upper limb to be supplied by all 5 segments (roots) of the brachial plexus Current TB: innervation: lateral and medial nerves; clavicular head (C5C6), sternocostal head (C7C8T1). The bold numbers indicate the main segmental innervation

Answer 19

A Explanation Triangular space or medial triangle Boundaries Inferior: superior border of teres major Lateral: long head of triceps Superior: teres minor (or subscapularis) Contents: Scapular circumflex vessels (axillary artery, subscapular artery and scapular circumflex artery) Triangular interval or lateral triangle Boundaries Superior: teres major Medial: long head of biceps brachii Lateral: humerus (some sources say lateral head of triceps) Contents Radial nerve passes through on its way to the posterior compartment of the arm. Profunda brachii also passes from anterior to posterior. Quadrangular space Boundaries Superior: teres minor (inferior margin) Inferior: teres major (superior margin) Medially: long head triceps brachii (lateral margin) Laterally: Surgical neck of the humerus Anteriorly: subscapularis Contents: Axillary nerve Posterior circumflex humeral vessels (artery and vein)

Answer 20

A Explanation It does not assist PQ in pronation. It is supplied in 60% primarily on its lateral portion by the anterior interosseus branch of the median nerve. The medial portion is supplied by the ulnar nerve. It is the strongest and bulkiest muscle of the forearm. Its action is enhanced by wrist extension Note: answer from Last's anatomy

Answer 21

D Explanation Circumflex scapula is a branch of the subscapular artery Branches of the Axillary Artery: 1 branch of the 1st part (between lateral border of 1st rib and medial border of pectoralis minor) - superior thoracic artery 2 branches of the 2nd part (posterior to pectoralis minor) - thoracoacromial artery - lateral thoracic artery 3 branches of the 3rd part (between the lateral border of pectoralis minor and the inferior border of teres major) - subscapular artery - anterior circumflex humeral artery - posterior circumflex humeral artery

Answer 22

C Explanation The ulnar nerve lies on the medial/ulnar side of the ulnar artery. it supplies the superficial arch, It disappears from the cubital fossa by passing beneath the fibrous arch of flexor digitorum superficialis (FDS). Old and current TBs, say that the superficial palmer arch is formed by the direct continuation of the ulnar artery. The deep palmer arch is formed by the deep branch of the ulnar artery. (not a direct continuation) Extra: Deep palmar arch is formed by direct continuation of radial art. with contribution by deep branch of ulnar art. on medial side

Answer 23

D Explanation Lateral attachment: scaphoid (tubercle) and trapezium (ridge) Medial attachment: pisiform and hook of hamate

Answer 24

A Explanation The Flexor retinaculum attached to the scaphoid and trapezium (radially) to the pisiform and hamate (ulnar). Extensor retinaculum originated from the radius to the triquetral and pisiform bones

Answer 25

C Explanation The trapezium and scaphoid can be felt in the floor of the snuff box between the radial styloid process and the first metacarpal. It contains the radial artery, cephalic vein and cutaneous branches of the radial nerve. It is most obvious with the thumb fully extended; this draws the tendons up and produces a triangular hollow between them. It is the abductor pollicis longus and the extensor policis brevis that form one boundary on the radial or thumb side, and the extensor pollices longus forms the other boundry on the ulnar side

Answer 26

D Explanation The radial nerve (the superficial branch of the radial nerve) lies lateral to the radial artery. It lies deep to brachioradialis. It passes deep to both tendons which form the palmer border of the anatomical snuff box. The anterior and posterior carpal arches supply the articulations of the wrist and carpus

Answer 27

C Explanation The AC joint is an atypical synovial joint. The articular surfaces are covered by fibrocartilage and separated by an incomplete wedge shaped articular disc. The coracoclavicular ligament (made up by the conoid and trapezoid ligament) is extremely strong and the principal factor in providing stability to the joint. Movements are passive; muscles which move the scapula cause it to move on the scapula. No muscles connect the articulating bones to move the AC joint. Nerve supply: see below- NOTE: THIS QUESTION POSES SOME CONFUSION. IN A PREVIOUS RECOMMENDED TEXT, THE NERVE SUPPLY OF THE AC JOINT IS THE SUPRACLAVICULAR NERVE. IN THE PRESCRIBED TEXT, THE NERVE SUPPLY OF THE AC JOINT IS THE LATERAL PECTORAL AND AXILLARY NERVE AND THE LATERAL SUPRACLAVICULAR NERVE (ACCORDING TO HILTON'S LAW) Arterial supply: suprascapular and thoracoacromial arteries

Answer 28

D Explanation Serratus anterior is supplied by the long thoracic (C5, C6, C7) nerve. The nerve to subclavius comes off the superior trunk. The suprascapular nerve comes off the anterior division of the superior (upper) trunk. Divisions do not give branches, they come off roots, trunks and cords. Extra: "C5,C6,C7 raise your wings up to heaven": C5,C6,C7 injury causes inability to raise arm past 90 degrees up to heaven, and results in a winging of the scapula. Long thoracic nerve roots (C5,C6,C7) innervate Serratus anterior.

Answer 29

C Explanation OLD source: The superficial lymphatics follow the veins and the deep lymphatics follow the arteries. Most of the drainage from the palm passes to the dorsum of the hand. Most superficial lymphatics accompanying the cephalic vein to enter the apical axillary lymph nodes. IMPORTANT NOTE: The current textbook writes: deep lymphatic vessels, less numerous then superficial vessels, accompany the major deep veins in the upper limb (basilic and cephalic) and terminate in the numeral axillary lymph nodes. Superficial lymphatic vessels originate from the digital lymphatic vessels of the digits and lymphatic plexus of the palm. Most drainage from the palm passes to the dorsum of the hand. Some vessels accompanying the basilic vein enter the cubital lymph nodes, proximal to medial epicondyle and medial to basilica vein. I have added a user provided explanation. It may help: In clinically oriented anatomy (6th Ed) states "deep lymphatic vessels, less numerous than superficial vessels, accompany the major deep veins in the upper limb" BUT it then proceeds to call the deep veins of the upper limb the basilic and cephalic veins - but these are actually the SUPERFICIAL veins of the upper limb. So the explanation in the book doesn’t make sense. I think the answer should read: Deep lymphatic vessels, less numerous than superficial vessels, accompany the major deep veins in the upper limb (radial, ulnar and brachial veins) and terminate in the humeral axillary lymph nodes. Below is from teach anatomy: Superficial Lymphatic Vessels----- The superficial lymphatic vessels of the upper limb initially arise from lymphatic plexuses in the skin of the hand (networks of lymphatic capillaries beginning in the extracellular spaces). These vessels then travel up the arm in close proximity to the major superficial veins: The vessels shadowing the basilic vein go on to enter the cubital lymph nodes. These are found medially to the vein, and proximally to the medial epicondyle of the humerus. Vessels carrying on from these nodes then continue up the arm, terminating in the lateral axillary lymph nodes. The vessels shadowing the cephalic vein generally cross the proximal part of the arm and shoulder to enter the apical axillary lymph nodes, though some exceptions instead enter the more superficial deltopectoral lymph nodes. ---Deep Lymphatic Vessels--- The deep lymphatic vessels of the upper limb follow the major deep veins (i.e. radial, ulnar and brachial veins), terminating in the humeral axillary lymph nodes. They function to drain lymph from joint capsules, periosteum, tendons and muscles. Some additional lymph nodes may be found along the ascending path of the deep vessels.

Answer 30

A Explanation The RADIAL nerve and the profunda brachii artery (radial collateral branch) pierce the lateral intermuscular (IM) septum. The MEDIAN nerve runs with the brachial artery, anterior to the medial intermuscular septum. Medial head of triceps arises from the posterior surface of humerus, inferior to radial groove. It has brachioradialis and extensor carpi radialis longus as anterior relations. The lateral IM septum extends along the lateral supracondylar line and fades out behind the insertion of the deltoid Note: supracondylar and supraepicondylar are synonymous. The lateral suprachondylar ridge is the same as the lateral supraepicondylar ridge

Answer 31

A Explanation It is innervated by the musculocutaneous nerve (C5, C6), and some of the lateral part of the muscle is innervated by a branch of the radial nerve (C5, C7). Proximal attachment: distal half of anterior surface of humerus Distal attachment: coronoid process and tuberosity of ulna (Note: in Last's it says a small part of brachialis is supplied by the radial nerve) It arises from the lower 2/3 of the humerus. It is a flexor of the elbow joint.

Answer 32

A Explanation Pronator quadratus is the most powerful pronator, palmaris longus is absent in 10% of cases. FCR does not run over the entire length of the flexor retinaculum

Answer 33

A Explanation Injury to the lateral cord of the brachial plexus results in injury to the musculocutaneous nerve (MC), the lateral pectoral nerve and the lateral root that forms part of the median nerve of the median nerve (MN). Muscles affected MC: coracobrachialis, biceps brachii and brachialis (note that brachialis is innervated by some fibres of the radial nerve) Lateral pectoral nerve: pectoralis major and some part of the pectoralis minor (via branches which connect to the medial pectoral nerve) MN: muscles of the anterior forearm compartment (except flexi carpi ulnaris and ulnar half of flexor digitorium profundus), five intrinsic muscles in thenar half of the palm and palmer skin

Answer 34

A Explanation The FDP makes up the deep (third) layer of the forearm. It has a medial part which inserts into the bases of the distal phalanges of the 4th and 5ht digits. A lateral part which inserts into the bases of the distal pahalanges of the 2nd and 3rd digits. Its main action is the flexion of the diatal phalanges at the distal interphalangeal joints. Nerve supply of the medial part is the ulnar nerve. Lateral part by the anterior interosseous nerve (form the median nerve). Note: unlike the FDS, the FDP can flex only the index finger independently, thus the fingers can be independently flexed at the proxinal but not the distal interphalangeal joints

Answer 35

A Explanation According to Moore- the clavicle is the first long bone to ossify (via intramembranous ossification), beginning during the 5th and 6th embryonic weeks.

Answer 36

D Explanation The current textbook states that the clavicle is the first long bone to ossify (via intramembranous ossification), beginning during the 5th and 6th week embryonic weeks. A secondary ossification centre appears at the sternal end and forms a scale like epiphysis that begins to fuse with the shaft (diaphysis) between 18-25yrs of age and is completely fused to it between 25-31Yrs of age. This is the last of the epiphysis of long bones to fuse

Answer 37

A Explanation Dermatomes as per clinical Moore: C3,C4 region at base of neck, extending laterally over shoulder. C5 lateral aspect of arm C6 lateral forearm and thumb C7 middle three finger and centre of posterior aspect of forearm C8 little finger, medial side of hand and forearm T1 medial aspect of forearm and inferior arm T2 medial aspect of superior arm and skin of axilla both last two options are correct in this question.

Answer 38

D Explanation Laceration of the wrist often causes median nerve injury because the nerve is relatively close to the surface. The median nerve is commonly injured just proximal to the flexor retinaculum This results in paralysis of the muscles of the thenar eminence. (except the adductor pollicis and deep head of the flexor polices brevis) and the first two lumbricals. Hence opposition of the thumb is not possible, and fine control movements of the 2nd and 3rd digits are impaired. Sensation is also lost over the thumb and adjacent two and a half fingers on the palmer side and only finger tips on the dorsal side. The radial nerve supplies the dorsal radial aspect of the hand and the first web space via its superficial branch. If the median nerve is severed in the forearm or at the wrist, the thumb cannot be opposed. However, the APL and adductor policis (supplied by the posterior interosseous and ulnar nerves, respectively) may imitate opposition, although ineffective. You do not loose complete loss of thumb flexion if the median nerve is cut at the wrist as Flexor Pollicis longus originates and is innervated above the wrist. You may have weakened flexion because of the absence of innervation of Flexor pollicis brevis, but you will not have complete loss of flexion. Extra: a user asked a valid question; What if the laceration cut the FPL tendon too? Then there would be total loss of thumb flexion. The question doesn't specify the extent of the cut/injury. I agree, the question doesn't specify, however, an injury/cut, I think, would mean superficial. If the word deep is used, this may change things. Extra: another user remarked- they are saying he is unable to abduct the thumb. (Haven’t said total or partial) I would have thought he has severed his APL as well. That makes me think it is a deep cut. Not a good question at all. Remember, the questions are based on recall. Having knowledge of the type of question is just as important as having the original question (which may not be possible)

Answer 39

B Explanation The muscle arises from the common origin, the medial ligament of the elbow joint and the tubercle on the medial border of the coronoid process of the ulna. It is considered the largest muscle of the superficial layer in the forearm. However, the FDS actually forms an intermediate layer between the superficial and deep groups of the forearm muscles. The tendons pass beneath the flexor retinaculum, the middle and ring finger tendons lie superficial to those to the index and little finger. The tendons are enclosed in a common synovial flexor sheath. In the forearm the muscle has the median nerve plastered to its deep surface by areolar tissue. The FDS flexes the middle phalanges of the medial four fingers at the proximal interphalangeal joints. It also flexes the proximal phalanges at the metacarpophalangeal joints and the wrist joint. It is supplied by the median nerve only. Note: This question is from the old textbook. Still worthwhile to leave in the bank

Answer 40

A Explanation Carpal tunnel results from any lesion which reduces the size of the tunnel. The median nerve is the most sensitive structure in the tunnel. The median nerve also has two terminal sensory branches that supply the skin of the hand; hence paraesthesia, hypoaesthesia or anaesthesia may occur in the lateral three fingers of the hand. The median nerve also has one terminal motor branch- the recurrent branch, which serves the three thenar muscles. Progressive loss of coordination and strength in the thumb (due to weakness of APB-abductor pollices brevis and OP- opponens pollices) may occur if the compression is not alleviated. The palmer cutaneous branch passes above the carpal tunnel, thus sensation to the central palm remains unaffected

Answer 41

C Explanation The dorsal scapular nerve is a branch of the roots of the brachial plexus. It arises from the posterior aspect of anterior ramus of C5 with a frequent contribution form C4. It supplies the rhomboids and occasionally levator scapulae. It pierces the middle scalene and descends deep to levator scapulae and rhomboids.

Answer 42

C Explanation The deltoid muscle is divided into unipennate anterior and posterior parts and a multipennate middle part; the parts of the deltoid can act separately or as a whole. It attaches proximally to the lateral third of the calvicle, acromion and spine of scapula. Distally it attaches to the deltoid tuberosity of the humerus. It is supplied by the axillary nerve (C5, C6). Muscle action includes flexion and medial rotation of the arm (anterior part), abduction of the arm (middle part) and extension with lateral rotation of the arm (posterior part). Supraspinatus initiates abduction.

Answer 43

D Explanation The axillary artery begins at the lateral border of the first rib as the continuation of the subclavian artery and ends at the inferior border of the teres major. It passes posteriorly to the pectoral minor into the arm and becomes the brachial artery when it passes the inferior border of the teres major. It is divided into three parts by the pectoralis minor. The subscapular artery is the largest branch of the axillary artery. The axillary vein lies distally on the anteromedial side of the artery, with its terminal part anteroinferior to the artery. Extra: Additionally branches of axillary artery can be memorised with mnemonic "Screw The Lawyer, Save A Patient": Sup Thoracic; Thoracoacromial; Lateral Thoracic; Subscapular; Anterior Circumflex Humeral; Post Circumfelx Humeral.

Answer 44

D Explanation The deep branch of the radial nerve (also called the posterior interosseous nerve C7, C8) supplies motor innervation to all the muscles with fleshy bellies located entirely in the posterior compartment of the forearm-distal to the lateral epicondyle of the forearm. Extra: The deep branch of radial/posterior interosseous nerve. Its origin is the motor terminal branch of radial nerve, in cubital fossa. Course in the forearm: deep branch exists cubital fossa winding around neck of radius, penetrating and supplying supinator; emerges in posterior compartment of forearm as posterior interosseous; descends on membrane with artery of same name. Muscles include- extensor carpi radialis brevis, extensor digitorum, extensor carpi ulnaris, extensor digiti minimi, supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis. Bachioradialis and extensor carpi radialis longus are supplied by the radial nerve C6, C7, by a branch arising above the elbow joint. Anconeus is supplied by the radial nerve as well (C7C8)

Answer 45

C Explanation The palmer aponeurosis fans out form the distal border of the flexor retinaculum. From each of its two sides a septum dips deeply into the palm. That from the ulnar border is attached to the palmer border of the fifth metacarpal bone. The space so formed medial to it is the hypothenar space. The remaining part of the palm is divided into two spaces by the septum that dips in from the radial border of the palmer aponeurosis to the palmer surface of the third metacarpal bone. This septum lies obliquely and separates the thenar space on its radial side from the midpalmer space or beneath the palmer aponeurosis. The septum usually passes deeply between the flexor tendons of the index and middle finger The spaces can be called compartments as well. The midpalmer/central compartment contains the flexor tendons and their sheaths, lumbricals, superficial palmer arterial arch and the digital vessels and nerves. The hypothenar space/compartment contains the hypothenar muscles and fascia and the thenar muscles and fascia re contained in the thenar space. The deepest muscular plane of the palm is the adductor compartment containing the adductor pollicis

Answer 46

A Explanation C6 does not perform forearm pronation but rather supination. Other movements include shoulder extension and upperlimb adduction, elbow flexion and extension, wrist extension and medial rotation of the upper limb. Note: although the upper limb is commonly called the arm, it is actually referring to the upper part of the limb between the shoulder and the elbow. The forearm is that part between the elbow and the wrist. Extra: https://www.kenhub.com/en/library/anatomy/myotomes C5-C6 Flexion of the arm at the shoulder joint C6 Supination at the shoulder joint C6-C7 Extension of the forearm at the elbow jointFlexion and extension of the hand at the wrist joint C6-C8 Medial rotation, adduction, and extension of the arm at the shoulder joint C7-C8 Pronation at the shoulder jointFlexion and extension of the digits of the hand at the metacarpophalangeal and interphalangeal joints

Answer 47

D Explanation C3, C4= region at base of neck, extending laterally over the shoulder C5= lateral aspect of the arm, C6= lateral forearm and thumb C7= Middle and ring fingers, and centre of the posterior aspect of the forearm C8= little finger, medial side of hand and forearm T1= medial aspect of forearm and inferior arm T2= medial aspect of superior arm and skin of axilla

Answer 48

D Explanation Quite a "bony" type of question Coronoid fossa of the humerus and a coronoid process of the ulna. Trochlear of the humerus and a trochlera notch (or fossa) of the ulna. The radial notch is found on the ulna. The radial tuberosity is found on the radius

Answer 49

B Explanation The axillary vein is formed by the union of the brachial vein and the basilic vein at the inferior border of the teres major. The axillary vein ends at the lateral border of the first rib and becomes the subclavian vein. The axillary vein lies initially (distally) on the anteromedial side of the axillary artery, with its terminal part anteroinferior to the artery. It is made up of three parts that correspond to the three parts of the axillary artery. It is important to remember that the axillary vein receives the thoracoepigastric vein(s) which are formed by the anastomosis of the superficial veins from the inguinal region with tributaries of the axillary vein. These veins constitute a collateral route that enables venous return in the presence of IVC obstruction

Answer 50

B Explanation The axillary sheath is a sleeve like extension of the cervical fascia. Neurovascualr structures ensheathed are axillary blood vessels (axillary artery, vein and its tributaries), lymphatic vessels and several axillary lymph nodes, the cords and branches of the brachial plexus and axillary fat

Answer 51

B Explanation Injury to the median nerve at the flexor retinaculum will result in paralysis of the thenar muscles and the first two lumbricles. Hence opposition of the thumb and fine control movements of the 2nd and third digits are impaired. Sensation is lost over the thumb and adjacent two and a half fingers. Because the palmer cutaneous branch of the median nerve arises just proximal to the flexor retinaculum and travels into the palm superficial to the flexor retinaculum, the skin of the central palm will be spared. Extra If the median nerve is severed in the forearm or at the wrist, the thumb cannot be opposed; however the APL and the adductor pollicis (supplied by the posterior interosseous and ulnar nerves, respectively) may imitate opposition, although ineffective

Answer 52

D Explanation When the midshaft of the humerus is fractured, the radial nerve may be injured in the radial groove. Under such circumstances, the triceps is usually not completely paralysed but only weakened because only the medial head is affected. The other two heads' (lateral and long) nerve supply have a higher origin and are not affected. The muscles in the posterior compartment of the forearm that are supplied by the more distal branches of the nerve are paralysed. The classical wrist drop appears, caused by the inability to extend the wrist and the fingers at the metacarpophalangeal joints. There is sensory loss distal to the wrist but it is minimal (on account of the overlapping median and ulnar nerve supply) and is confined to a small area of skin over the first dorsal interosseous space. Note: If the radial nerve is injured superior to the origin of its branches to the triceps brachii results in paralysis of the triceps, brachioradialis, supinator and extensor muscles of the wrist and fingers. Loss of sensation in areas of the skin supplied by the nerve also occurs. The superficial branch of the radial nerve is entirely cutaneous in its distribution, supplying sensation to the dorsum of the hand and fingers. It originates as a branch of the radial nerve in the forearm. Note: The interphalangeal joints can still be extended weakly through the action of the intact lumbricals and interossei, which are supplied by the median and ulnar nerves. In the Radial Groove The radial nerve is tightly bound within the spiral groove of the humerus. Thus, it is most susceptible to damage with a fracture of the humeral shaft. Motor functions The triceps brachii may be weakened, but is not paralysed (branches to the long and lateral heads of the triceps arise proximal to the radial groove). Muscles of the posterior forearm are affected. The patient is unable to extend at the wrist and fingers. Unopposed flexion of wrist occurs, known as wrist-drop.

Answer 53

A Explanation The scapula is a triangular, flat bone which has a medial, lateral and superior border. It also has a superior, lateral and an inferior angle. The superior border joins the base of the coracoid process. The concave costal surface of most of the scapula forms a large subscapular fossa. The lateral border terminates in the truncated lateral angle of the scapula, the thickest part of the bone that bears the broadened head of the scapula. The glenoid cavity is the primary feature of the head

Answer 54

C Explanation The common digital nerves lie deep to the superficial palmar arch. Palmar nerves supply palmar surface and they end dorsally by supplying the dorsal nail beds. The digital artery lies dorsal to the nerve. Digital nerves are purely sensory. If a digital nerve is cut, the patient feels numbness on the corresponding side of the finger. Motor function in the finger should be normal, because it is controlled by the tendons, whose muscles are innervated more proximally in the forearm. Impairment of motor function (other than pain with movement) suggests that tendon injury also is present. Note: lumbrical muscles-arise from the each of the four profundus tendon and passes along the radial side of the corresponding metacarpophalangeal joint, on the palmer surface of the deep transverse metacarpal ligament, to be inserted by a tendon into the extensor expansion on the dorsum of the first phalanx. The two unicapital lumbricals (1,2) are supplied by the median nerve and the two biciputal lumbricals (3,4) are supplied by the ulnar nerve.

Answer 55

B Explanation Adduction of the fingers= T1 Digital flexion=C7 C8 Digital extension=C7 C8 Pronation=C7 C8

Answer 56

B Explanation The carpal tunnel lies between the flexor retinaculum and the carpal bones. The median nerve and the flexor tendons of the fingers and thumb pass through this tunnel. The four tendons of the superficial flexor are separate and lie in two rows, with the middle and ring finger tendons in front of the index and little finger tendons. The tendons of the flexor digitorium profundus lie deeply in one plain, with only the tendon to the index finger being separate from the others, which remain attached together till they reach the palm. All eight tendons of the superficial and deep flexors share a common tendon sheath, which does not invest them completely but is reflected from their radial sides, where arteries gain access. The tendon of flexor pollices longus lies in its own synovial sheath as it passes through the fibro-osseous tunnel. At the lateral end of the tunnel a deep lamina from the flexor retinaculum is attached to the medial lip of the grove of the trapezium. The tendon of flexor carpi radialis, enclosed in its own synovial sheath runs in the groove in this subcompartment of the carpal tunnel. The median nerve passes deep to the flexor retinaculum between the flexor digitorium superficialis tendon to the middle finger and the flexor carpi radialis tendon. The ulnar nerve lies on the front of the reticulum lateral to the pisiform bone, with the ulnar artery lateral to the nerve (in the canal of Guyon)

Answer 57

B Explanation The movements of supination and pronation occur at the superior and inferior radioulnar joints. In full supination, the anatomical position, the radius lies lateral and parallel to the ulna. During pronation the distal radius rotates in front of and around the head of the ulna, carrying the hand with it. In full pronation the shaft of the radius lies across the front of the ulna with the distal end of the radius lateral to the ulnar head (this statement comes from the old resource.It is wrong, the radius in full pronation lies medial to the ulnar head and not lateral to it) During supination these movements are reversed. The axis of movement of the radius relative to the ulna passes through the radial head and ulnar styloid. The ulnar is not usually entirely stationery during pronation and supination. The distal end of the ulna moves slightly posterolaterally in pronation and anteromedially in supination, these movements being effected by anconeus and the bicepital aponeurosis respectively. Supination is more powerful inaction, carried out by biceps and supinator muscles. Pronation is produced by pronator quadratus and pronator teres. About 140 degrees of rotation occurs at the radioulnar joints during pronation and supination.

Answer 58

D Explanation Abductor pollicis brevis-recurrent branch of median nerve (C8, T1) Palmaris brevis-superficial branch of the ulnar nerve Palmer interossei 1st-3rd-Deep branch of the ulnar nerve (C8, T1) Extensor carpi radialis longus-Radial nerve (C6, C7) Extensor carpi radilias brevis- Deep branch of the radial nerve (C7, C8)

Answer 59

C Explanation The latissimus dorsi muscle is responsible for medial rotation of the humerus, as well as extension and adduction. It is supplied by the thoracodorsal nerve. The dorsal scapular nerve supplies the rhomboids, which retract the scapula. The long thoracic nerve supplies the serratus anterior muscle, which rotates and protracts the scapula. The nerve to subclavius supplies the subclavius muscle, which depresses the clavicle.

Answer 60

B Explanation The thoracodorsal nerve arises from the posterior cord of the brachial plexus. Other branches include the upper and lower subscapular nerves, and axillary nerve, before continuing as the radial nerve. The long thoracic nerve arises from the C5, C6, and C7 nerve roots. The nerve to subclavius arises from the C5 and C6 nerve roots. The suprascapular nerve arises from the upper trunk of the brachial plexus (C5, C6)

Answer 61

A Explanation The FCU tendon attaches to the pisiform, hook of hamate and 5th MC. The ulnar artery enters the and via the ulnar canal, between the pisiform and hook of hamate. Profuse bleeding suggests arterial involvement and thus this is the likely affected muscle structure

Answer 62

B Explanation FCU: flexes and aDDucts wrist. Lumbricals: flex MCPJ and extend IPJ (act with interossei) Dorsal interossei: abduct digits 2-4 from the axial line FDP: the medial and lateral parts are responsible for the flexion of the distal phalanges 4/5 and 2/3 at the DIPJ respectively

Answer 63

A Explanation The radial nerve supplies sensation to the lateral 3.5 digits and associated hand area of the dorsum of the hand.

Answer 64

A Explanation The axillary artery has three parts located relative to the pec minor muscles. The 1st part is proximal to the pec minor and gives off the superior thoracic artery. The 2nd part is posterior to the pec minor and gives off the thoracoacromial artery and lateral thoracic artery. The 3rd part is distal and gives off the subscapular, and anterior and posterior circumflex arteries.

Answer 65

B Explanation Carpal Tunnel Syndrome affects the median nerve, which supplies the thenar muscles (opponens pollicis, abductor pollicis brevis, flexor pollicis brevis), and the lateral two lumbricals.

Answer 66

D Explanation Myotomes: C5 - shoulder abduction C6 - elbow flexion C7 - elbow extension C8 - finger flexion T1 - finger abduction & adduction

Answer 67

B Explanation C5 is responsible for shoulder flexion, abduction and lateral rotation; as well as sensation over the lateral shoulder/arm

Answer 68

B Explanation The major muscles involved in shoulder flexion are the pec major and deltoid, with the deltoid being supplied by the axillary nerve. The musculocutaneous nerve supplies the coracobrachialis, biceps brachii and brachialis (both elbow flexion). The coracobrachialis muscles assists shoulder flexion. Flexion of the shoulder Pectoralis major (medial and lateral pectoral nerve) Deltoid (axillary nerve) Assisted by coracobrachialis (musculocutaneous nerve) Flexion of the elbow Brachialis (musculocutaneous nerve) Biceps Brachii (musculocutaneous nerve)

Answer 69

A Explanation Glenohumeral ligaments stabilize the anterior parts of the shoulder joint. Coracohuneral and acromioclavicular ligaments provide superior stability. The transverse humeral ligament bridges intertubercular sulcus, between two tubercles, holding the head of biceps in groove

Answer 70

B Explanation The musculocutaneous nerve begins opposite the inferior border of the pec minor, pierces the coracobrachialis, and continues distally between the biceps and the brachialis.

Answer 71

D Explanation Structures crossing the floor of the snuff box include the radial artery, superficial branch of the radial nerve, and cephalic vein.

Answer 72

D Explanation The radial nerve gives off branches to the brachioradialis and ECRL from the arm, proximal to the elbow. The FPL is supplied by the median nerve. The radial nerve pierces the supinator in the forearm, supplying it before becoming the posterior interosseous nerve and supplying muscles of the posterior compartment of the forearm.

Answer 73

D Explanation The deltoid and teres minor atrophy when the axillary nerve (C5, C6) is severely damaged. Because it passes inferior to the humeral head and winds around the surgical neck of the humerus, the axillary nerve is usually injured during fracture of this part of the humerus. It may also be damaged during anterior dislocation of the glenohumeral joint and by compression from incorrect use of crutches. The radial nerve courses in the radial groove of the humerus shaft and thus is susceptible to injury with midhumeral fracture.

Answer 74

C Explanation The Radial Nerve (n. radialis; musculospiral nerve), the largest branch of the brachial plexus, is the continuation of the posterior cord of the plexus. Its fibres are derived from the fifth, sixth, seventh, and eighth cervical and first thoracic nerves. source: https://www.imaios.com › e-Anatomy › Anatomical-Parts

Answer 75

D Explanation Recurrent branch of median nerve supplies opponens pollicis, abductor pollicis brevis and the superficial head of flexor pollicis brevis. Interossei are innervated by the deep branch of the ulnar nerve, the 1st-2nd lumbricals by the median nerve, and extensor pollicis longus by the posterior interosseous nerve

Answer 76

C Explanation The musculocutaneous nerve is derived from the lateral cord of the brachial plexus and innervates the biceps brachii, brachialis, and coracobrachialis muscles (C5–C6), terminating as the lateral cutaneous nerve of the forearm. Injuries to the musculocutaneous nerve are associated with weakness of arm flexion and sensory loss along the lateral forearm. In children, musculocutaneous neuropathies are rare and generally caused by compressive or overuse injuries. Musculocutaneous nerve innervates the muscles in the anterior compartment of the arm: Biceps brachii, Brachialis, Coracobrachialis. These muscles flex the upper arm at the shoulder and the elbow. In addition, the biceps brachii also supinates the forearm. A useful mnemonic to help you remember these muscles is BBC.

Answer 77

C Explanation The best place to compress the brachial artery (manually or with a tourniquet) to control haemorrhage is medial to the humerus near the middle of the arm. Because the arterial anastomoses around the elbow provide a functionally and surgically important collateral circulation, the brachial artery may be clamped distal to the origin of the deep artery of the arm without producing tissue damage. The anatomical basis for this procedure is that the ulnar and radial arteries will still receive sufficient blood through the anastomoses around the elbow. Arm-extends form the shoulder to the elbow Forearm-is the distal unit of the articulated strut (extension of the upper arm). It extends form the elbow to the wrist.

Answer 78

B Explanation The two left bronchial arteries usually arise directly from the thoracic aorta. The single right bronchial artery may also arise directly from the aorta; however, it commonly arises indirectly, either by way of the proximal part of one of the upper posterior intercostal arteries (usually the right 3rd posterior intercostal artery) or from a common trunk with the left superior bronchial artery.

Answer 79

B Explanation The common place for measuring the pulse rate is where the radial artery lies on the anterior surface of the distal end of the radius, lateral to the tendon of the FCR. Here the artery is covered by only fascia and skin. The artery can be compressed against the distal end of the radius, where it lies between the tendons of the FCR (flexor carpi radialis) and APL (abductor pollicis longus). A radial pulse can also be felt by pressing lightly in the anatominal snuffbox.

Upper limb Flashcards

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