Musculoskeletal: Anatomy - Upper limb summary Flashcards
Boundaries and contents of clavipectoral triangle
Clavicle superiorly, pec major medially, deltoid laterally
Contents: medial and lateral pectoral nerves, cephalic vein
Boundaries and contents of quadrangular space
Teres minor superiorly, teres major inferiorly, neck of humerus laterally, long head of triceps medially, subscapularis anteriorly
Contents: axillary nerve, posterior circumflex humeral artery
Boundaries and contents of the triangular interval
Teres major superiorly, neck of humerus laterally, long head of triceps medially
Contents: radial nerve, profunda brachii artery
Borders and branches of the axillary artery
1 branch in 1st part, 2 branches in 2nd part, 3 branches in third part
First part: lateral 1st rib to medial pec minor, superior thoracic artery
Second part: posterior to pec minor, thoracoacromial and lateral thoracic arteries
Third part: lateral pec minor to inferior border teres major, subscapular and anterior and posterior circumflex humeral arteries
Mnemonic branches of the axillary artery
Send The Lord to Say A Prayer:
- Superior thoracic
- Thoracoacromial
- Lateral thoracic
- Subscapular
- Anterior circumflex humeral
- Posterior circumflex humeral
Musculocutaneous nerve
Roots: C5-7
Motor: anterior compartment of arm (flexors)
Sensory: lateral cutaneous nerve of forearm
Muscles in anterior compartment of arm
Biceps brachii
Brachialis
Coracobrachialis
Motor innervation of anterior compartment of arm
Musculocutaneous (C5-7)
Arterial supply of anterior compartment of arm
Muscular branches of brachial artery
Biceps tendon reflex nerve root
C6
Origin, insertion and actions of biceps brachii
Long head: supraglenoid tubercle of scapula
Short head: coracoid process of scapula
Insertion: radial tuberosity and fascia of forearm via bicipital aponeurosis
Action: prime supinator, flexes arm and forearm
Origin and insertion coracobrachialis
Origin: coracoid process of scapula
Insertion: medial humerus
Origin and insertion brachialis
Origin: shaft of humerus
Insertion: ulnar tuberosity
Motor innervation of posterior compartment of arm
Radial nerve (C5-8, T1)
Triceps tendon reflex nerve root
C7
Origin and insertion of triceps brachii
Long head: infraglenoid tubercle of scapula
Lateral head: humerus (superior to radial groove)
Medial head: humerus (inferior to radial groove)
Insertion: Olecranon
Borders and contents of the triangular SPACE
Teres minor superiorly, teres major inferiorly, long head of biceps laterally
Contents: circumflex scapular artery and vein
Course of the radial nerve
Continuation of posterior cord of brachial plexus
Lies on tendon of latissimus dorsi in posterior wall of axilla
Enters arm via triangular interval
What is the largest branch of the brachial plexus?
Radial nerve
Axillary nerve
Roots: C5-6
Motor: deltoid, teres minor, long head of triceps
Sensory: superior lateral cutaneous nerve of arm (“regimental badge” area)
Median nerve
Roots: C6-8, T1
Motor: flexors of forearm (except FCU and medial FDP), thenar muscles, lateral lumbricals
Sensory: palmar cutaneous branch and digital cutaneous branch (lateral palm and 3.5 fingers anteriorly)
Radial nerve
Roots: C5-8, T1
Motor: extensors of arm and forearm
Sensory: posterior arm and forearm, posterolateral aspect of hand (not including distal fingers)
Ulnar nerve
Roots: C8, T1
Motor: FCU, medial FDP, muscles of hand (except thenar muscles and lateral lumbricals)
Sensory: anterior and posterior medial 1.5 fingers, associated palmar area
Arterial supply of posterior compartment of arm
Profunda brachii
Muscles in posterior compartment of arm
Triceps brachii
Anconeus
Origin and insertion of anconeus
Origin: lateral epicondyle of humerus
Insertion: lateral olecranon and superoposterior ulna
Muscles in anterior compartment of forearm
Superficial x4: FCU, FCR, palmaris longus, pronator teres
Intermediate x1: FDS
Deep x3: FPL, FDP, pronator quadratus
Innervation of anterior compartment of forearm
All except FCU and medial FDP by median nerve (with deep muscles by anterior interosseous branch of median nerve)
Arterial supply of anterior compartment of forearm
Common origin of superficial and intermediate muscles of anterior compartment of forearm
Medial epicondyle of humerus via common shared tendon
From lateral to medial: pronator teres, FCR, palmaris longus, FCU
Additionally:
- Pronator teres: also arises from coronoid process
- FCU: also arises from olecranon process
- FDS: also arises from coronoid process and radial head
Actions of muscles of anterior compartment of forearm
Superficial: flexion of wrist (plus abd/adduction by FCR and FCU respectively, pronation by PT)
Intermediate: PIPJ and MCPJ flexion
Deep: pronation by pronator quadratus, digit flexion by FDP and FPL
Distal attachments of superficial anterior forearm compartment muscles
Pronator teres: mid-shaft of radius
FCR: base of 2nd metacarpal
Palmaris longus: flexor retinaculum and palmar aponeurosis
FCU: base of 5th metacarpal, pisiform and hook of hamate
What two structures pass between the ulnar and radial heads of FDS?
Median nerve
Ulnar artery
Proximal and distal attachments of FDP
Proximal: ulna and interosseous membrane
Distal: base of distal 2nd-5th phalanges
Proximal and distal attachments of FPL
Proximal: radius and interosseous membrane
Distal: base of distal 1st phalanx
Proximal and distal attachments of pronator quadratus
Proximal: distal ulna
Distal: distal radius
Muscles of the posterior compartment of the forearm
6x superficial:
- Brachioradialis
- ECU
- ECRL and ECRB
- Extensor digitorum
- Extensor digiti minimi
5x deep (from superficial to deep / proximal to distal):
- Supinator
- Abductor pollicis longus
- EPL and EPB
- Extensor indicis
Innervation of the posterior compartment of the forearm
Radial nerve
Which of the 6x superficial muscles of the posterior compartment of the forearm originate from the common extensor tendon?
Originating from common extensor tendon on lateral epicondyle of humerus:
- ECU
- ECRB
- Extensor digitorum
- Extensor digiti minimi
Attachments and action of brachioradialis
From lateral supracondylar humerus to distal radius
Weak flexor, assists in supination
Attachments of ECRL and ECRB
ECRL from lateral supracondylar humerus, ECRB from common extensor tendon at lateral epicondyle of humerus
Attach to base of 2nd and 3rd metacarpals
Which nerves of the posterior compartment of the forearm are supplied by the deep and posterior interosseous branches of the radius?
Radial nerve:
- Brachioradialis
- ECRL and ECRB
Deep branch of radial nerve:
- Supinator
- ECU
- Extensor digitorum
- Extensor digiti minimi
Posterior interosseous branch of radial nerve:
- EPL and EPB
- Extensor indicis
- Abductor pollicis longus
Where do the tendons of the extensor muscles for the digits insert?
Into the extensor hoods of each respective digit
Some have more than one muscle insert (i.e. thumb, index finger, and little finger)
Distal attachment of ECU
Base of 5th metacarpal
What is tennis elbow vs golf elbow?
Tennis elbow: lateral epicondylitis (aim for “lateral” line of the court)
Golf elbow: medial epicondylitis (aim for “middle” of the fairway)
The radial nerve passes between the two heads of which muscle?
Supinator
Proximal and distal attachment of supinator
Proximal: two heads, one from lateral epicondyle of humerus (common extensor origin) and one from posterior ulna
Distal: posterior surface of proximal radius
Proximal and distal attachment of abductor pollicis longus
Proximal: interosseous membrane, adjacent radius and ulna (just distal to supinator)
Distal: base of 1st metacarpal
Proximal and distal attachment of EPB
Proximal: posterior radius and interosseous membrane
Distal: base of 1st proximal phalanx
Proximal and distal attachment of EPL
Proximal: posterior ulna and interosseous membrane
Distal: base of 1st distal phalanx
Proximal attachment of extensor indicis
Posterior ulna and interosseous membrane
What does the recurrent branch of the median nerve innervate?
Thenar muscles
Which thenar muscles are innervated by the ulnar nerve?
Deep head of flexor pollicis brevis
Adductor pollicis
Attachments of flexor pollicis brevis
Trapezium and flexor retinaculum to base of 1st proximal phalanx
Attachments of opponens pollicis
Trapezium and flexor retinaculum to lateral side of 1st metacarpal
Attachments of abductor pollicis brevis
From scaphoid, trapezium and flexor retinaculum
To lateral side of 1st proximal phalanx
Attachments of flexor digiti minimi
Hook of hamate and flexor retinaculum to base of 5th proximal phalanx
Attachments of abductor digiti minimi
Pisiform and FCU tendon to base of proximal phalanx
Attachments of opponens digiti minimi
Hook of hamate and flexor retinaculum to medial aspect of 5th metacarpal
Which has two heads: dorsal or palmar interossei?
Dorsal
Attachments of adductor pollicis
One head from 3nd metacarpal, one from capitate and 2nd-3rd metacarpals
Inserts into base of 1st proximal phalanx
What does the radial artery pass through to form the dorsal palmar arch?
Two heads of adductor pollicis
Boundaries and contents of the cubital fossa
Superior border: line between medial and lateral epicondyles of humerus
Medial border: pronator teres
Lateral border: brachioradialis
Roof: bicipital aponeurosis (also contains median cubital vein connecting basilic and cephalic veins)
Floor: brachialis proximally, supinator distally
Contents from lateral to medial (Really Need Beer to Be At My Nicest):
- Radial nerve
- Biceps tendon
- Brachial artery
- Median nerve
Boundaries of the cubital tunnel
Medial: medial epicondyle of humerus
Lateral: olecranon
Floor: elbow joint capsule, medial collateral ligament of elbow
Roof: ligament spanning medial epicondyle of humerus and olecranon
Extensor tendon compartments of the wrist and their contents
From lateral to medial
Compartment 1:
- EPB
- Abductor pollicis longus
Compartment 2:
- ECRL
- ECRB
Lister’s tubercle separates
Compartment 3:
- EPL
Compartment 4:
- Extensor digitorum
- Extensor digiti minimi
Compartment 5:
- Extensor digiti minimi
Compartment 6:
- ECU
What is De Quervain’s tenosynovitis?
Inflammation affecting tendons of extensor compartment 1 (EPB and abductor pollicis longus)
Borders of the carpal tunnel
Carpal arch forms concave base and sides
Formed laterally by scaphoid and trapezium tubercles
Formed medially by hook of hamate and pisiform
Roof formed by flexor retinaculum
Contents of the carpal tunnel
9 tendons: FPL (in its own sheath), 4x FDP and 4x FDS (all in the same sheath)
Median nerve (AFTER giving off palmar cutaneous branch)
What tendon is contained within the flexor retinaculum itself?
FCR
Borders of the anatomical snuffbox
Ulnar border: EPL
Radial border: EPB and abductor pollicis longus
Proximal: radial styloid
Floor: scaphoid, trapezium
Roof: skin and subcutaneous tissue
Borders of the ulnar canal
Medial: pisiform, FCU tendon, abductor digiti minimi
Lateral: hook of hamate
Roof: palmar carpal ligament
Floor: flexor retinaculum
Contents of the anatomical snuffbox
Radial artery
Superficial branch of radial nerve (sensory)
Cephalic vein
Inflammation of which bursa causes olecranon bursitis?
Subcutaneous olecranon bursa
What are the three bursae of the elbow joint?
Intratendinous: inside triceps brachii tendon
Subtendinous: between triceps brachii tendon and olecranon
Subcutaneous: between olecranon and overlying connective tissue
Which structures may be damaged with elbow dislocation?
Dislocation is typically posterior
Ulnar collateral ligament may be torn
Ulnar nerve may be damaged
Four ligaments of the wrist
Palmar radiocarpal: from radius to both rows of carpal bones on palmar surface
Dorsal radiocarpal: from radius to both rows of carpal bones on dorsal surface
Ulnar collateral: from ulnar styloid to triquetrum and pisiform
Radial collateral: radial styloid to scaphoid and trapezium
What is the clinical presentation of a lunate dislocation?
Lunate compresses carpal tunnel -> paraesthesia in median nerve distribution and weakness of thenar muscles
Describe the course of the brachial artery
Continuation of axillary artery at inferior border of teres major
Gives off profunda brachii immediately (which travels with radial nerve in radial groove)
Terminates at the cubital fossa, bifurcating into radial and ulnar arteries
Describe the course and distribution of the radial artery
Runs under brachioradialis and lateral to FCR in distal forearm (can be palpated here)
Gives off palmar carpal branch near distal border of pronator quadratus (anastamoses with ulnar palmar carpal branch to form palmar arch)
Crosses floor of anatomical snuffbox and pierces 1st dorsal interossei
Gives off dorsal carpal branch (anastamoses with ulnar dorsal carpal branch to form dorsal arch)
Supplies posterolateral forearm
Describe the course and distribution of the ulnar artery
Descends deep to superficial and intermediate layers of anterior forearm muscles
At cubital fossa gives off common interosseous artery which divides into anterior and posterior interosseous arteries
Gives off palmar carpal branch at distal forearm
Passes superficial to flexor retinaculum in ulnar canal to enter hand
Gives off dorsal carpal branch proximal to pisiform
Supplies anteromedial forearm
Divide the course of the anterior and posterior interosseous arteries
From common interosseous artery (branch of ulnar artery) at cubital fossa
Anterior: runs on anterior interosseous membrane then pierces membrane proximal to pronator quadratus, joins dorsal carpal arch
Posterior: passes to posterior interosseous membrane and runs between superficial and deep extensors (supplies both), joins anterior interosseous artery at distal forearm after it pierces through interosseous membrane
Which arch gives off the digital arteries?
Palmar (superficial)
Describe the course of the median nerve
Descends initially lateral to brachial artery
Halfway down the arm, median nerve crosses brachial artery to enter cubital fossa at medial aspect
Exits cubital fossa and travels between two heads of pronator teres, then descends between FDP and FDS
Gives off anterior interosseous nerve to supply deep flexor muscles
Gives off palmar cutaneous nerve just proximal to wrist
Enters hand via carpal tunnel
Terminates by dividing into recurrent branch (supplies thenar muscles) and palmar digital nerves (sensation to lateral 3.5 digits, motor to lateral 2 lumbricals
Why does a fracture of the radial head not produce a wrist drop?
Innervation and function of ECRL still intact
Describe the course of the ulnar nerve
Descends in medial arm between axillary artery laterally and axillary vein medially
At midpoint of arm, pierces medial septum to enter posterior compartment of arm and passes through elbow in ulnar tunnel
In the forearm it pierces FCU and travels deep to it
Gives off muscular, palmar cutaneous and dorsal cutaneous branches
Travels superficial to flexor retinaculum of wrist in ulnar canal (lies medial to the ulnar artery)
Terminates in hand by giving rise to superficial and deep branches
Describe the course of the basilic vein
Originates from medial dorsal venous network of hand
Ascends medial aspect of upper limb
Moves deep into the arm at the inferior border of teres major
Combines with brachial veins to form axillary vein
Describe the course of the cephalic vein
Arises from lateral dorsal venous network of hand
Ascends anterolateral aspect of upper limb
Travels in deltopectoral groove at shoulder
Enters axilla via clavipectoral triangle
Within axilla, empties into axillary vein
