ANATOMY LIMBS; Session 2, 3, 4 and 5 - The shoulder and arm (shoulder to elbow), The elbow, forearm and wrist, the hand and the brachial plexus Flashcards
What are the bones of the shoulder and arm?
Scapula, clavicle and humerus are the main ones
What are the key features of the scapula?
What are the key features of the clavicle?
What are the key features of the humerus?
NB: the surgical neck is more commonly damaged than the anatomical neck; epicondytes are important for muscle attachment; intertubercular groove is important for muscle and tendon attachments
What are the muscular compartments of the arm and shoulder?
Anterior pectoral girdle muscles, posterior pectoral girdle muscles, intrinsic shoulder muscles, anterior compartment of upper arm and posterior compartment of upper arm
Which muscles are present in the anterior pectoral girdle muscles?
Pectoralis major, pectoralis minor, subclavius, serratus anterior (between ant and post compartments)
What are the proximal and distal attachments; movement of pectoralis major?
Proximal: Medial 1/3rd of clavicle, the sternum and costal cartilages.
Distal: lateral lip of intertubercular sulcus (groove).
Movement: Adducts and medially rotates humerus with lesser action on scapula
What are the proximal and distal attachments of pectoralis minor?
Proximal: Ribs/costochondral joints.
Distal: coracoid process of scapula
What is the subclavius and its function?
Anchors the clavicle
Where does the serratus anterior attach to and what nerve supplies it?
Runs from medial border of scapula to anterior attachments on ribs (1-9); supplied by long thoracic nerve
Which muscles are present in the posterior pectoral girdle?
Trapezius, Latissimus dorsi, Levator scapulae, Rhomboids
Where is the trapezius attached and what are its functions/supplied by?
Motor supply by CNXI; major actions on scapula
Proximal attachment: Spinous process of ribs
Distal attachment: spine of scapula and clavicle/acromion process
What is the latissimus dorsi and what is its nerve supply/function?
Supplied by thoracodorsal nerve
Extends, adducts, rotates the humerus; pulls body up to arms during climbing and important in rowing.
Proximal attachment: spinous processes (S1-T8) and IlIac crest forming thoracolumbar fascia
Distal attachment: intertubercular groove
What are the rhomboids and what is their nerve supply/function?
Supplied by dorsal scapular nerve; retracts, rotates and fixes the scapula.
Major is broader than minor.
What is the levator scapulae and what is its nerve supply/function?
Supplied by dorsal scapular nerve (+C3/4); elevates and rotates the scapula.
Distal attachment: superior angle of scapula
Proximal attachment:Transverse processes of C1-4
What are the intrinsic shoulder muscles?
- Deltoid
- Teres major
- Rotator cuff muscles
- supraspinatus
- infraspinatus
- teres minor
- subscapularis
What is the deltoid and what is its nerve supply/function?
Supplied by axillary nerve; abducts arm
Proximal attachment: Attaches to spine of scapula (spinal deltoid) and clavicle (clavicular deltoid).
Distal attachment: deltoid tuberosity
What is the rotator cuff?
Acts to fix the head of the humerus in the glenoid fossa -> supraspinatus important in initiating abduction of arm for first 15’ then deltoid takes over.
Converge on head of humerus and attaches onto spine of scapula.
What is the Teres Major and what is its nerve supply/function?
Adducts and medially rotates arm; innervated by lower subscapular nerve.
Forms thick spindle of muscle
Proximal attachment: Inferior angle of scapula
Distal attachment: medial lip of intertubercular sulcus
What is the anterior compartment of the arm?
- Biceps brachii (form a bicepetal tendon and attaches to radial tuberosity and supraglenoid tubercle of scapula)
- Brachialis (attaches to shaft of humerus and below coronoid process of ulna)
- Coracobrachialis (comes of coracoid process and shaft of humerus)
Supplied by musculocutaneous nerve
What is the posterior compartment of the arm?
- Triceps brachii (infraglenoid tubercule, form triceps tendon which attaches to olecranon process of ulna - crosses shoulder joint so can act there)
- Aconeus (crosses elbow joint - attaches to lateral epicondyte)
Supplied by radial nerve (all posterior muscles supplied by radial nerve)
What are the joints present in the arm?
Sterno-clavicular joint, acromio-clavicular joint, gleno-humeral joint (shoulder), Scapulo-thoracic joint (not a joint, just scapula rubbing against thoracic wall), elbow joint
Which joints make up the pectoral girdle?
- SCJ (has an articular disc from which the whole arm hangs off so has a lot of back muscles and core muscles which help to balance the weight of the limb)
- ACJ (capsule to hold it together)
- GHL
- STJ
What is the gleno-humeral joint?
- Ball-and-socket synovial joint
- Glenoid labrum is a thin line of cartilage which helps stabilise into the shallow socket
- Stability of the joint comes from the ligaments and muscles not from the bony articulation
- Joint held together by the rotator cuff muscles.
What is the function of the rotator cuff and the shoulder joint?
To hold humeral head within the glenoid; rotator cuff depresses humeral head. Nb: no muscles underneath the shoulder joint so common dislocation of humerus is downwards
What are the movements of the shoulder joint and which muscles produce these movements?
- Flexion: clavicular head of pec. major, coracobrachialis, ant. fibres of deltoid and biceps
- Extension: lat. dorsi
- Abduction: supraspinatus (1st 15’) and central fibres of deltoid (after 15’)
- Adduction: Pec. major, lat.dorsi
- Internal rotation: subscapularis
- External rotation: infraspinatus, Teres minor
What are the movement of the scapulo-thoracic joint and which muscles are responsible?
All of scapula.
- Elevation: Sup trapezius, levator scapulae and rhomboids.
- Depression: Inf. trapezius, pec minor, serratus anterior.
- Protraction: Pec. minor, serratus anterior.
- Retraction: Rhomboids, middle trapezius, lat. dorsi.
- Rotation: glenoid fossa faces upwards or downwards as scapula rotates
- up: sup trapezius, inf. trapezius, serratus ant.
- down: pec minor, lat. dorsi, rhomboids and levator scapulae
What is the axilla?
Gateway for nerves and blood vessels to enter and leave the upper limb; shaped like truncated pyramid
What are the structures present in the axilla?
Arteries (axillary artery and branches), veins (axillary veins and tributaries), lymphatic vessels and lymph nodes, nerves (brachial plexus)
What are the neurovascular contents of the axilla?
What are the arteries of the arm?
- SCA over first rib ->
- Axillary artery at lower border of teres major ->
- Brachial artery giving off profunda brachii and divides at elbow into ->
- Ulnar and radial arteries.
Also have subscapular arteries which anastomose quite heavily
What are the veins of the arm?
- Cephalic vein (superficial) up lat. border of arm;
- Basilic vein (sup) up medial border of arm joining Venae comitantes (groups of veins that accompany the artery which join into basilic vein) to form:
- Axillary vein in arm (joined by cephalic vein in axilla) and then
- Becomes SCV at level of 1st rib.
What is the lymphatic drainage of the arm?
- Superficial and deep systems, run with veins;
- Cubital lymph nodes;
- Delto-pectoral LN;
- Axillary LN;
- SC lymph trunk;
NB: long thoracic nerve and thoracodorsal nerve can become damaged when LN removed during surgery
Why are the axillary lymph nodes so important?
Drain the breast as well; so when breat cancer occurs and they need to be removed can cause lymphoedema of the arm, forearm and hand
What are the nerves in the brachial plexus of the arm?
Lateral and medial pectoral nerve supply the pectorals. The musculocutaneous nerve supplies anterior compartment of the arm
What are the largest nerves of the brachial plexus?
- Axillary nerve (C5),
- musculocutaneous nerve (C567),
- Ulnar nerve (C8T1),
- Median nerve (C678T1),
- Radial nerve (C5678T1 - main posterior supply of arm e.g. triceps)
Where are the common sites of damage?
Dislocation affects the axillary nerve
What is the main function of the arm?
The functions of all the muscles revolve around that of the hand - to hold objects and manipulate them
What is the sterno-clavicular joint?
Synovial joint; Composed of 2 portions separated by fibrocartilage articular disc -> very strong which arises from the very strong sterno-clavicular ligaments -> when damaged can result in sterno-clavicular subluxation or dislocation. Only connection of the clavicle to the axial skeleton and allows movement of clavicle in 3 different planes
What is the acromio-clavicular joint?
Synovial joint between acromial end of clavicle and acromion -> joint stabilised by: acromioclavicular ligament, coracoclavicular ligament (conoid and trapezoid ligaments) and coraco-acromial ligament (often cause of impingement of glenohumeral joint, but weak)
What are the common injuries to the ACJ?
Frequently injured when falling onto outstretched hand; minor dislocations occur when the acromioclavicular joint is torn; severe dislocations when the coraco-clavicular is also torn
Where does the capsule of the glenoid-humeral joint extend to?
- Capsule of shoulder joint extends from the glenoid to the humeral head,
- the subacromial bursa (above humeral head to underlying acromion - often site of pathology in impingement of GHJ)
- extension around long head of biceps as it lies within inter-tubercular groove of humerus
What are the important ligaments of the GHJ?
Coraco-acromial ligament (prevents rising of the humerus against the acromion, forming an arch); beneath coraco-acromial arch is the subacromial bursa and supraspinatus tendon; gleno-humeral ligaments ,(strengthen the anterior portion of shoulder capsule); coracohumeral ligament (strengthens capsule sup.) and transverse humeral ligament (holds tendon of long head of biceps in intertubercular tube)
Which muscles are involved in resisting dislocation at the gleno-humeral joint?
Rotator cuff muscle (hold humeral head against glenoid cavity); deltoid; coracobrachialis; short and long head of biceps
What are the boundaries of the axilla?
- Base: skin, subcut tissue extending from arm to chest;
- apex between first rib, clavicle and sup. border of subscapularis;
- ant wall formed by pec. major and minor;
- post wall by scapula and subscapularis (sup) and teres major and lat dorsi (inferiorly);
- medial wall: chest wall (rib 1-4) and serratus anterior;
- lateral wall formed by intertubercular groove of humerus
Which nerve supplies the supraspinatus/infraspinatus?
Suprascapular nerve
Which nerve supplies pectoralis major?
Medial/Lateral pectoral nerve
What does the axillary nerve supply?
Teres minor and deltoid (with skin overlapping)
What are the vertebral levels of the scapula landmarks?
Sup angle = T2; medial end of scapular spine lies at T3; inferior angle at T7
What is the delto-pectoral groove?
Triangle bounded by the clavicle sup, deltoid laterally and pec major medially
How do you test the sternocleidomastoid actions and what nerve supplies it?
Turn head R/L against resistance -> spinal accessory CNXI and C3/4
How do you test trapezius actions and nerve supply?
Raise both shoulders against resistance -> CNXI, C3/4
How do you test Pec major actions and nerve supply?
Adduct the abducted arm against resistance -> latera/mdial pectoral C5678 T1
How do you test serratus anterior actions and nerve supply?
Both arms outstretched with palms against wall and asked to press forward strongly -> Long thoracic C56
How do you test Teres major actions and nerve supply?
Adduct arm against resistance; see and palpate muscle in post axillary fold -> lower subscapular C56
How do you test Lat dorsi actions and nerve supply?
Abduct arm to 90’ and adduct against resistance; see and palpate in post. axillary fold -> thoracodorsal C678
How do you test deltoid actions and nerve supply?
Abduct upper arm against resistance -> axillary nerve C56
How do you test biceps actions and nerve supply?
Flex the elbow against resistance
Which muscles are responsible for elbow flexion?
Biceps, brachialis, brachioradialis (pronator teres)
Which muscles are responsible for elbow extension?
Triceps (anconeus)
Which bones are present in the elbow, forearm and wrist?
Humerus, radius, ulna and carpal bones -> proximal row: scaphoid, lunate, triquetrum, pisiform; distal row: trapezium, trapezoid, capitate, hamate.
NB: Radial is on thumb side which is lateral side of arm
What are important features of the bones of the elbow?
Fossae for radius, coronoid fossa, olecranon process on posterior
What are the bones of the forearm?
Olecranon is on the ulna; distal ends have styloid process (stability of wrist joint and muscle attachment); connected via an interosseus membrane (similar to a joint)
What is an important feature of the interosseus membrane?
The interosseous membrane separates the anterior and posterior compartments, and is a site of attachment for muscles in the forearm
What are the bones of the wrist?
The distal ends of the radius and ulna articulate with the proximal row of carpal bones, with the exception of pisiform (a sesamoid bone).
What are the muscle compartments of the elbow and forearm?
Ant/post compartment of arm; anterior compartment of forearm (sup compartment and deep compartment); post compartment of forearm
Which muscles act on the elbow from the ant. compartment of arm?
Radial tuberosity (flexion and supination of forearm) and biceps aponeurosis merges with fascia of the region
What are the functions of the forearm muscles?
Hand and wrist operated by remote control y these muscles; actially take origin from distal humerus and radius/ulna
What is pronation and supination?
Supination is palms forward and pronation is palm down -> most relaxed in mid prone position
Which muscles are present in the sup. ant. compartment of the forearm?
Pronator teres (PT), Flexor carpi radialis (FCR), Palmaris longus (PL), Flexor digitorum superficialis (FDS), Flexor carpi ulnaris (FCU)
Which muscles are present in the deep ant. compartment of the forearm?
Flexor digitorum profundus (FDP), Flexor pollicis longus (FPL), Pronator quadratus (PQ)
Which muscles are present in the anterior compartment of the forearm?
Have a deep and superficial pronator;
NB: all the muscles cross the elbow joint apart from the pronators
What are the fascia present in the forearm?
The flexor retinaculum forms the roof of the carpal tunnel and is an important structure; antebrachial fascia (palmar carpal ligament) holds down the tendons in the wrist
Which muscles are present in the extensor compartment of the forearm?
Note that some parts of the proximal attachments are on the interosseous membrane.
Which muscles are present in the extensor compartment of the forearm that move the wrist joint?
Extensor carpi radialis longus (ECRL) Extensor carpi radialis brevis (ECRB) Extensor carpi ulnaris (ECU)
Which muscles are present in the extensor compartment of the forearm that move the digits?
Extensor digitorum (ED) Extensor indicis (EI) Extensor digit minimi (EDM)
Which muscles are present in the extensor compartment of the forearm that move the thumb?
Abductor pollicis longus (APL) Extensor pollicis brevis (EPB) Extensor pollicis longus (EPL)
Important notes about anatomical terminology:
Carpi = wrist mover and acts on radial/ulnar bones. Digitorum muscles act on group of digits - pollicis=thumb, indicis=index and digiti minimi= little finger
What is the anatomical snuff box in the forearm?
Scaphoid is easily broken and can trap the radial artery and cause necrosis of distal end of thumb
What are the joints present in the forearm?
Elbow joint; proximal/distal radio-ulnar joint; wrist joint
What is the elbow joint?
- Synovial hinge joint between humerus proximally and ulna/radius distally;
- distal humerus articulates with radius via capitulum and with ulna via trochlea. Olecranon bursa which frequently becomes inflamed
What ligaments are present in the elbow joint?
Arranged to stabilise the joint, but allow pronation/supination movements.
Medial/lateral collateral ligaments, annular ligament
How does the carrying angle vary between sexes?
Angle is larger in women to accommodate larger pelvis
What are the proximal and distal radio-ulnar joints?
What are the wrist and distal radio-ulnar joint?
How does the wrist and the distal radio-ulnar joint interact?
The distal ulna does not articulate directly with the triquetrum carpal bone. An articular disc intervenes.
What are the movements of the elbow joint?
Flexion: Brachialis, biceps (brachioradialis and pronator teres); extension: triceps (anconeus)
What are the movements of the radio-ulnar joints?
Supination: Supinator, biceps (EPL, ECRL); pronation: pronator quadratus, pronator teres, (FCR, PL, brachioradialis)
Pronation vs supination of forearm with muscles involved
What are the movements of the wrist joint?
- Flexion: FCR and FCU – important;
- Long flexors of thumb and fingers (PL, APL).
- Extension: ECRL, ECRB, ECU – important;
- Long extensors of the thumb and fingers.
- Radial deviation (abduction): APL, FCR, ECRL, ECRB.
- Ulnar deviation (adduction): ECU, FCU.
What are the arteries of the forearm?
- Ulnar and Radial arteries (brachial artery divides at level of radial neck)
- Ulnar art. has common interosseous branch which immediately branches to give the anterior and posterior interosseous atreries.
- Arches of the hand – anastomosis of the radial and ulnar arteries
What is the cubital fossa?
Space anterior to elbow joint; contains brachial artery and medial nerve
What are the veins present in the forearm?
Cephalic and Basilic veins arise from the dorsal venous arch of the hand. Commonly connected at the cubital fossa by the median cubital vein (not always present or prominent).
Why is the median cubital vein important?
Median cubital vein is commonly used in phlebotomy. When median cubital vein is absent, cephalic or basilic in the region are used to take blood.
What are the superficial veins of the region?
What are the deep veins of the region?
Follows the arteries
What is the lymphatic drainage of the region?
- Superficial and deep systems, run with veins;
- Cubital lymph nodes;
- Axillary nodes are also draining nodes for the distal parts of the upper limb
What are the main nerves for the forearm?
Musculocutaneous nerve (lateral of forearm) - C567; ulnar nerve (C8/T1), median nerve (C678T1), radial nerve (C5678T1)
What is the musculocutaneous nerve?
Sensory to the lateral forearm as lateral cutaneous nerve of forearm
What is the median nerve?
- Courses through the anterior compartment of the arm (no significant branches)
- lies anterior to the elbow, with the brachial artery (easily damaged!)
- Main nerve to the muscles of the forearm
What is the ulnar nerve?
Courses via the posterior compartment of the upper arm; No significant branches in the upper arm; Lies behind the medial epicondyle at the elbow (easily damaged) and then passes between the heads of FCU; The main nerve of the hand -> supplies the DCU and medial portion of FDP and sensory supply to medial aspect of ventral forearm
What is the radial nerve?
- Supplies all the muscles of the posterior compartments of the upper arm and forearm;
- Passes around the body of the humerus at its mid-shaft in the radial groove (easily damaged!);
- Courses via the anterior compartment of the upper arm more distally;
- Divides just above the level of the elbow into:
- the superficial radial nerve (sensory)
- the Deep branch – the posterior interosseous nerve (motor) which
- descends between heads of supinator and
- ends as pseudoganglion below extensor retinaculum
What are the nerves of the forearm?
Radial nerve to posterior muscles; ulnar nerve to FCU and ulnar half of FDP; median nerve to all remaining ant. muscles
Which joints allow flexion and extension at the wrist region?
Wrist joint, midcarpal joint and carpo-metacarpal joints
What is important about the development of the clavicle?
First long bone to ossify at 5th week of IUL via intermembranous ossification
How do you test the brachioradialis?
Elbow flexed against resistance with forearm in midprone position (radial - C567)
How do you test for FCU?
Wrist flexed against resistance (ulnar - C78)
How do you test for palmaris longus?
Wrist flexed against resistance (median C67)
How do you test for FCR?
Wrist flexed against resistance (median C67)
What are the carpal bones?
What are the features of the radius?
- Cylindrical head at proximal end;
- shaft, and broad distal end with styloid process;
- radius rotates around ulna in supination/pronation involving proximal and distal radio-ulnar joints
What are the features of the ulna?
Proximal end has two projections: olecranon and coronoid process;
Connected by shaft and distal end with head and styloid process
What is the proximal radial-ulnar joint?
Uni-axial pivot-type synovial joint which allows head of radius to rotate within the annular ligament (attached to margins of radial notch of ulna) -> supination and pronation take place here
What is the distal radial-ulnar joint?
Pivot-type synovial joint that allows radius to rotate around the distal ulna and the articular surfaces are held together by a fibrocartilage articular disc -> supination and rotation take place here
What is the interosseus membrane of the forearm and its function?
Fibrous sheet that connects radius and ulna forming a fibrous joint (syndesmosis) between the 2 bones; divides forearm into ant and post compartments and transfers forces from radius to ulna to humerus and vice versa
What is the wrist joint and its ligaments?
- Elipsoid synovial joint between distal radius and its associated triangular fibrocartilage articular disc with the proximal row of carpal bones.
- Ligaments:
- ulnar/radial collateral ligament;
- palmar radiocarpal/ulnocarpal ligament;
- dorsal radiocarpal ligament
- intercarpal ligament
What are the movements of the wrist joint?
Flexion/extension, radial/ulnar deviation and circumduction
How does the ulnar artery and nerve enter then hand?
Descends in anterior compartment of forearm and passes into hand anteriorly on the ulnar side (lateral to FCU); ulnar nerve lies medial to it at wrist joint
What does the ulnar artery supply?
Medial muscles of forearm via common interosseous artery, anterior interosseous artery and posterior interosseous artery; forms palmar arches in the hand with the radial artery
How does the radial artery/nerve enter the hand?
Descends the lateral aspect of forearm under the cover of the brachioradialis muscle; on wrist lies anteriorly on radial aspect, crosses the floor of the anatomical snuff box and anastamosis with branches of the ulner artery to form palmar arches
What does the radial nerve supply?
Brachioradialis, ECL, ECRB, supinator, ED, ED minimi, ECU, APL, EPB, EPL, E indicis
What is the median nerve?
Descends in anterior compartment of arm, with no branches; lies medial to brachial artery anterior to elbow, where it is at risk of damage by suprachondylar fracture of humerus. Descends into forearm between heads of pronator teres to become principal motor nerve of compartment - at ant. wrist it lies superficially to FDP, FDS and deep to palmaris longus, prior to entering hand via carpal tunnel
What does the median nerve supply?
Pronator teres, FDP (lateral portion - index and middle finger), FDS, FCR, pronator quadratus and palmaris longus
What are the names of the digits?
Thumb, index, middle, ring little finger
What are the bones of the wrist and the hand?
Radius, Ulna, carpus (scaphoid, lunate, triquetum, pisiform, trapezium, trapezoid, capitate and hamate); metacarpal bones, phalanges
What are the bones in the wrist/hand?
The distal ends of the radius and ulna articulate with the proximal row of carpal bones, with the exception of pisiform = Sesamoid bones (bone developed within a tendon); thumb has 2 phalanges but all the other digits have 3.
What are the fascia of the palm?
- Palmar fascia
- Palmar aponeurosis: overlies the long flexor tendons of the hand;
- proximally continuous with the flexor retinaculum;
- distally continuous with the fibrous digital sheaths.
- Fibrous digital sheaths: contain the flexor tendons and their synovial sheaths
What are the compartments of the hand?
- Septa – medial and lateral from palmar apponeurosis to
- medially : to little finger metacarpal,
- laterally : to middle finger metacarpal
- Hypothenar compartment
- Central compartment
- Thenar compartment
- Adductor compartment
What are the muscle compartments of the hand?
Thenar compartment (thumb mound), adductor compartment (palm of hand), hypothenar (little finger), interossei and lumbricals
What are the thenar muscles?
Abductor pollicis brevis, flexor pollicis brevis, opponens pollicis
What are the adductor muscles?
Adductor pollicis
What are the hypothenar msucles?
Abductor digiti minimi, flexor digiti minimi, opponens digiti minimi
What are the interossei and lumbricals?
- Lumbricals (attach to tendons):
- flex MCP joints and
- extend the IPJs.
- Interossei (between metacarpal and phalangeal joint):
- palmar (adduct digits PAD),
- dorsal (abduct the digits DAB)
What are the intrinsic muscles of the hand?
What are the movements of the thumb?
What are the muscles that move the thumb?
- Abduction: APL, APB
- Adduction: Adductor pollicis, first dorsal interosseous
- Extension: EPL, EPB, APL
- Flexion: FPL, FPB
- Opposition: Opponens pollicis
What is the adductor pollicis?
Pollicis muscle supplied by the ulnar nerve
What supplies the thenar nerves?
Median nerve (most pollicis muscles apart from the adductor pollicis
Where do the lumbricals attach to?
Attach to the tandon -> 4 and 3 attach to digits on each side and 1 and 2 only on the distal side of the finger
What is the anterior tendinous anatomy of the hand?
- Fibrous digital sheath;
- Osseo-fibrous tunnels;
- In the tunnels run the long flexor tendons and their synovial sheaths;
- Annular and cruciform pulleys
- FDP and FDS tendons pass in the carpal tunnel beneath the flexor retinaculum
- enter a common synovial sheath then
- enter a digital synovial sheath, within its own fibrous digital sheath;
- Little finger and thumb sheaths continuous
- FDS splits around FDP
- FDS to middle phalanx,
- FDP to distal phalanx
What is the tendinous anatomy of the digits?
Fibrous digital sheath; A=annular and C= cruciate parts
What is the posterior tendinous anatomy of the hand?
- Extensor retinaculum;
- Synovial tendon sheaths;
- Inter-tendinous bands;
- Extensor expansions;
- Lumbricals and interossei attach to the expansions;
- Extensor digitorum, EI, EDM
What is the posterior tendinous anatomy of the digits?
What is the function of the extensor retinaculum?
To hold down the tendons in the posterior hand
What are the joints in the hand region?
- Distal radio-ulnar joint - Wrist joint - Intercarpal joints - Carpo-metacarpal and inter-metacarpal joints - Metacarpo-phalangeal joints - Interphalangeal joints
What are the intercarpal joints?
Joints between proximal row; between distal row and between proximal and distal -> some gliding occurs here
What are the carpometacarpal and intermetacarpal joints and their function?
- CMC of thumb to trapezium,
- CMC of digits,
- intermetacarpal joints ->
- function: flexion/extension, radial/ulnar deviation and circumduction
What are the functions of the metacarpophalangeal joints?
Flexion/extension, abduction/adduction (ulnar collateral ligament of thumb)
What are the functions of the interphalangeal joints?
- F/Ex only;
- proximal interphalangeal/distal interphalangeal with only called interphalangeal in thumb;
- volar plate (protection of anterior surface, thick pad of fascia)
What are the tendons of the digits?
What are the arteries of the hand?
- Ulnar (beside FCU in wrist,
- interosseous arteries in forearm,
- sup.palmar arch (palmar digital arteries),
- deep palmar branch);
- Radial artery (under brachioradialis beside FCR at wrist, in anatomical snuff box, deep palmar arch and palmar metacarpal arteries formed)
What are the deep veins of the hand?
Run with the arteries so arise from ulnar and radial arteries; form venae comitantes
What are the superficial veins of the hand?
- Superficial veins in the region of the Cubital Fossa are commonly used for phlebotomy or insertion of a venous line.
- The median cubital vein, linking the basilic and cephalic veins, is not always present.
What does the median nerve supply in the upper limb?
Main nerve to ant compartment of forearm and some supply to hand intrinsic muscles -> purely sensory and often damaged
What does the ulnar nerve supply in the upper limb?
Main nerve of hand, some ant. compartment (FCU and 1/2 of FDP) -> purely sensory and often damaged
What does the radial nerve supply in the upper limb?
Post. compartment of forearm and some sensory compartment of the hand -> purely sensory and often damaged
What does the median nerve supply in the hand?
What does the ulnar nerve supply in the hand?
What does the radial nerve supply in the hand?
How is the hand innervated?
Median supplies thenar muscles and the lateral 2 lumbricals;
Ulnar supplies all of the other intrinsic hand muscles
How is the sensory innervation of the hand distributed?
x
What forms the carpal tunnel?
Scaphoid, trapezoid, pisiform, hamate -> form a gutter, with the roof being the flexor retinaculum
What is contained in the carpal tunnel?
Median nerve, FPL tendons, 4 tendons of FDP, and 4 tendons of FDS
What are the types of grip?
NB: when going from loose to firm grip the little finger changes angle when tightening
What is a power grip?
Fingers are flexed around an object with counter pressure from the thumb -> activates long flexors of fingers and thumb, intrinsic muscles of palm and extensors of wrist joint
What is precision grip?
Object gripped with thumb and tips of fingers, with intrinsic muscles of the hand carrying out fine movements needed; typically wrist and fingers are held rigidly by long flexors and extensors
What is the palmar fascia?
Fascia of hand that lies in the palm -> specialisations (condensations) of palmar fascia in the hand that form palmar aponeurosis and fibrous digital sheaths
What is the palmar aponeurosis and where does it attach?
Well-defined region of palmar fascia in the hand that overlies the long flexor tendons in the hand -> proximal end of palmar aponeurosis is continuous with the flexor retinaculum and the palmaris longus tendon; distal end of palmar aponeurosis forms 4 bands which are continuous with the fibrous digital sheaths of each finger
What are the fibrous digital sheaths?
Tubes which contain flexor tendons and their sheaths -> space between palmar aponeurosis and bones of hand are separate into compartments by septa
What is the brachial plexus?
Passes under the clavicle
What are the spinal roots that form then brachial plexus?
C5-8 and T1
How are the cords named in the brachial artery?
According to their relationship to the axillary artery
What does each of the spinal roots innervate (motor)?
What is the segmental motor supply to the upper limb (which movements does each root supply)?
What are the dermatomes of the upper limb?
What is the sensory supply to the upper limb?
Why are dermatomes different from the cutaneous nerve patterns?
The spinal roots are carried through the nerves into the dermatomes, but the nerves are just one and innervate one part of the skin
What is the axillary nerve?
- C5 and 6;
- The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and vein;
- damaged in dislocations of shoulder as it becomes impinged
- supplies deltoid
How can you assess axillary nerve injury?
Abduction and check for sensory innervation in arm
What is the path of the radial nerve?
Travels very close to the humerus, so fractures in humerus can damage the nerve
What occurs if radial nerve is damaged?
- Wrist drop and anaesthesia of dorsal palm;
- loss of muscle mass evident in arm and forearm;
- loss of power grip
What is the journey of the musculocutaneous nerve?
What can damage the musculocutaneous nerve?
Not often injured in trauma as well protected -> but can be damaged during surgery of axillary region
What is the path of the ulnar nerve?
Behind medial epicondyle of humerus
What are the common sites of injury to the ulnar nerve?
Injuries to medial epicondyle of humerus cause injury to ulnar nerve at elbow -> self-harm can also damage the nerve
What does ulnar nerve injury cause?
Claw-like appearance -> loss of medial 2 lumbricals, so loss of flexion of MPJ and weakened IPJ extension;
sensation loss inconvenient -> thumb, index and middle finger spared
What is the ulnar nerve paradox?
Injuring ulnar at wrist has more severe clawing than at elbow due to ulnar also innervating the ulnar half of FDP, flexion of IP joints is weakened
What is the path of the median nerve?
What is the carpal tunnel?
NB: ulnar nerve runs outside of carpal tunnel
What is carpal tunnel syndrome and what sensation is lost?
Wasting of thenar eminence with furrow (adductor pollicis supplied by ulnar nerve so isn’t wasted); loss of both sensation and fine movement in the lateral digits is a serious disability
What is the long thoracic nerve?
Comes off the roots formed of C567
How is the long thoracic nerve damaged and what happens?
It is relatively superficial, above the serratus anterior; easily injured -> press against wall leading to winging of scapula resulting from loss of serratus anterior function
What is Erb-Duchenne palsy?
In upper root injury -> waiter’s tip position; Many muscles affected (shoulder, anterior arm). Forearm pronated by lack of biceps supination.
How can Erb-Duchenne palsy come about?
What causes Klumpke’s palsy?
Common cause is over-abduction due to gripping overhead to break a fall. T1 (and sometimes C8) or lower root injury during birth
What is Klumpke’s palsy - clinical features?
T1 mainly supplies the small muscles of the hand via the ulnar and median nerves.
Loss of their activity results in clawed hand.
Try to work out why this claw is resented.
How do you test the biceps tendon reflex?
Patient sitting comfortably with elbow semi-flexed and hand pronated.
Examiner places biceps thumb on biceps tendon and tap on nail bed of thumb with hammer.
Brisk flexion of forearm at elbow joint
How do you test the triceps tendon reflex?
Patient sitting comfortably with elbow semi-flexed and hand pronated.
Support elbow with one hand and tap triceps tendon directly with the tendon hammer
What are the three kind of hand positions with the different nerve injuries?
