Upper Limb Flashcards
Overview of the shoulder joint
High mobility
Limited stability
What are the bones of the shoulder joint?
-Clavicle
-Scapula (Acromion)
=Both together= Pectoral girdle
=Joins axial to appendicular skeleton
-Humerus (proximal)
What are the ligaments of the shoulder joint?
-Coraco-acromial ligament
-Capsule and Glenohumeral ligaments
-(Long head of biceps brachii= muscle)
=Multi-axial synovial ball and socket joint
=Articulation between head of humerus and glenoid fossa
What are the roles of the superficial muscles?
- Produce varied movements of scapula/ shoulder
- Multi-fibred/ multi-directional muscles
- Muscles most important at shoulder joint
What are the anterior superficial muscles of the shoulder?
-Deltoid
=anterior- flexion and medial rotation of humerus
=Posterior= extension
=Middle= abduction of humerus
= Insertion= Deltoid tuberosity
=Innervation= Axillary nerve (branch of brachial plexus)
-Pectoralis major
=Large fan shaped muscle on anterior chest wall
=Flexion, adduction of humerus, internal/medial rotation
=Origin= clavicle and sternum
=Insertion= intertubercular sulcus
=Innervation= medial and lateral pectoral
What are the posterior superficial muscles of the shoulder?
-Trapezius: superior, middle, inferior
=Large, superficial muscle of back
=Elevation (superior), depression (inferior), rotation and retraction (middle)
=Origin= occipital bone (C7-T12 vertebrae)
=Insertion= Lateral 1/3 clavicle, scapula
=Innervation= Accessory nerve
-Deltoid: middle, posterior
-Latissimus dorsi
Describe the Rotator Cuff
-4 Scapular muscles
-Stabilise and rotate shoulder
-Anterior
=Subscapularis- medial rotation, subscapular fossa
=Teres Major- lateral rotation
-Posterior
=Supraspinatus- abduction
=Infraspinatus- lateral rotation
=Teres Minor, Major
All attach to greater tubercle except subscapularis (lesser)
Overview of Elbow joint
-Hinge =Flexion =Extension -Pronation and supranational at radial ulnar joint -High stability -Limited mobility
What are the features of the elbow joint?
- Fibrous capsule- membrane thickened on medial and lateral aspects to form collateral ligaments
- Lateral (radial) collateral ligament= strong supporting, blend with annular
- Annular ligament= helps maintain contact of radial head with radial notch and capitulum during pronation and supination (envelopes head of radius)
- Medial (ulnar) collateral ligament= supplies stability
- Interosseous membrane
- Trochlear notch
What are the movement features of the anterior upper limb?
- Anterior arm
- Anterior forearm
- Medial epicondyle (CFO)
What are the movement features of the posterior upper limb?
- Posterior arm
- Posterior forearm
- Lateral epicondyle (CEO)
What are the anterior muscles of the arm?
-Biceps brachii
=Long head- under transverse humeral ligament to intertubercular sulcus to joint space to glenoid labrum
=Short head- medial aspect, coracoid process
=flexion and supination
-Brachialis- distal end, powerful flexor
=flexion
-Coracobrachialis (deep to short head biceps brachii)
(BBC)
All innervated by musculocutaneous nerve, plus brachialis innervation of radial nerve
What are the posterior muscles of the arm?
-Triceps brachii =Long Head- infer glenoid ligament, extensor =Medial Head =Lateral Head Innervated by radial nerve Extension
What are the muscles of the forearm?
- Brachiordialis= flexion and mid-pronation of forearm (posterior), radial nerve
- Pronator trees
- Pronator quadratus
- Supinator
Describe the Brachial plexus
- Complex nerve bundle innervating upper limb
- Arises from anterior rami of spinal nerves C5-T1, somatic (sensory motor innervation)
- Arranged around axillary artery
- 5 roots (C5-T1)
- 3 trunks
- 6 divisions
- 3 cords
- 5 named nerves/ branches
Describe the roots of the Brachial Plexus
5
Top two will merge (C5 and C6)
Middle C7
Bottom two merge (C8 and T1)
Describe the trunks of the Brachial Plexus
Top two roots merge to form superior/upper trunk
C7 root= middle trunk
Bottom two roots merge to form inferior/ lower trunk
So 3 trunks
Describe the divisions of the Brachial Plexus
Each trunk divides into 2 (posterior and anterior divisions)
Describe the cords of the Brachial Plexus
Organised around axillary artery
- 2 anterior cords= lateral and medial
- Posterior cord (behind axillary artery)
What are the named nerve branches?
- Musculocutaneous nerve (lateralcord)
- Axillary nerve (posterior)
- Median nerve (lateral and median)
- Ulnar nerve (medial)
- Radial nerve (posterior)
Describe the blood supply to the upper limb
- Subclavian artery (arises at bifurcation of innominate artery on RHS/ arch of aorta on LHS, divided into 3 parts by anterior scalene muscle)
- Axillary artery (from lateral border of 1st rib to inferior border of teres major, divided into 3 parts by pectoralis minor muscle)
- Brachial artery (closely related to median nerve, bifurcates into radial and ulnar around neck of radius with variation)
- Radial artery (runs through anatomical snuffbox= structure formed by three tendons, primarily contributes to deep palmar arch)
- Ulnar artery (larger than radial, primarily contributes to superficial palmar arch)
- Palmer arches
Describe the superficial drainage of the upper limb
- Axillary vein
- Cephalic vein= drains lateral side of forearm to axillary vein via medial cubital vein
- Basilic vein= drains medial side of forearm to axillary vein
- Median cubital vein
- Superficial veins drain into a dorsal venous network on back of hand
Describe the deep drainage of the upper limb
- Subclavian vein
- Brachial vein
- Radial and ulnar veins
What is the Carpal Tunnel?
Passage of tendons into hand/ Osseo-fibrous tunnel Deep to transverse carpal ligament 9 tendons: -Flexor digitorium superficialis x4 -Flexor digitorium profundus x4 -Flexor pollicis longus x1 Median nerve runs through Ulnar NVM runs outwith tunnel =Floor= carpal arch =Roof= Flexor reticulum -Paraesthesia, hypoesthesia, anaesthesia in lateral three and a half digits
What are the ligaments associated with the carpal tunnel?
- Palmar carpal ligament
- Transverse carpal ligament
What are the main supporting ligaments of the glenohumeral joint?
-Glenohumeral ligaments (anterior superior plane, attach to lesser tubercle) =Superior, Middle, Inferior -Coracohumeral ligament (Coracoid process to Greater Tubercle) -Transverse humeral ligament (Between tubercles) -Coracoacromial ligament 9superior aspect of joint vault) (Loose membrane for abduction)
Describe the Glenoid Labrum
-Glenoid ligament
-Intra-capsular structure, fibrocartilaginous ring that lines margin of glenoid cavity
(thin, small, triangular)
-Improves joint fit
-The superior aspect of the glenoid labrum continuous with long head of biceps brachii
Describe how pronation and supination occurs at the radio- ulnar joint
-Occurs at proximal and distal radio-ulnar joints (around head of radius)
-Supinators:
=Biceps brachii (cross over cubital fossa and attach onto radial tuberosity)
=Supinator (lateral, arises from lateral epicondyle, and supinator crest, inserts onto lateral proximal radial shaft)
-Pronators:
=Pronator teres (head of ulna and distal humerus, crosses forearm anteriorly and laterally, to mid shaft of radius- superficial)
=Pronator quadratus (deep muscle of forearm, spans distal end of ulnar and radius
Describe the compartments of the forearm
Anterior:
-Flexors= common origin (Medial epicondyle)
-Extrinsic hand muscles
-Primary nerve supply= Median
-Movements of wrist, flexion of fingers, pronation
Posterior:
-Extensors= common origin (Lateral epicondyle)
-Nerve supply= Radial
What are the layers of the anterior compartment of the forearm?
- Superficial= 4 muscles
- Intermediate= 1 muscle
- Deep layer= 3 muscles
Describe the Musculocutaneous nerve
anterior compartment of arm
- Large terminal branch of lateral cord
- Anterior branch
- Motor and sensory
- Pierces coracobrachialis
- Passes between biceps and brachialis
- Innervates all 3 (BBC) (motor aspect)
- Terminates as the lateral cutaneous nerve of the forearm
Describe the median nerve
Most of anterior forearm
- Large nerve derived of anterior cords
- M shape in axillary space as lateral and medial branches
- Enter cubital fossa
- Primary innovator of flexor compartment of forearm
- Passes through carpal tunnel
- Wide motor and sensory distribution within the hand
Describe the Ulnar nerve
Most of hand
- Derived primarily from medial cord
- Courses medially within the arm and forearm
- Passes posterior to medial epicondyle
- Innervates 1.5 muscles within forearm
- Primary innervator within hand
Describe the Axillary nerve
Shoulder region (deltoid)
- A branch of the posterior cord
- Passes through quadrangular space (bound by teres minor, major and humerus and triceps brachii)
- Innervates deltoid and teres minor muscles
- Provides sensory innervation to patch on lateral arm= Sergeants Patch
- Anterior dislocation of GHJ risks damage to axillary nerve
Describe the Radial nerve
Posterior compartment of arm and forearm
- Largest nerve of Brachial Plexus
- Arises as the terminal branch of posterior cord
- Runs within the spiral groove of the arm beneath deltoid tuberosity
- Posterior to anterior, divide into superficial and deep branch
- Provides motor and sensory innervation to all posterior compartments of upper limb
- Sensory to hand
- Mid shaft fractures of humerus risk damage
What are the compartment actions at the wrist and what are they innervated by?
Anterior= flexion= median nerve (ulnar nerve to 2 muscles closely associated with ulna) Posterior= extension= radial nerve
