Upper Limb Anatomy Flashcards
Branches of the axillary artery (classified by parts of axillary artery) (6)
1st part (medial to pec minor) = 1 branch: superior thoracic artery 2nd part (behind pec minor) = 2 branches: thoracoacromial trunk, lateral thoracic artery 3rd part (lateral to pec minor) = 3 branches: subscapular artery, anterior circumflex humeral artery, posterior circumflex humeral artery
Contents of the axilla (5)
Axillary artery + branches Axillary vein + tributaries Brachial plexus Lymph nodes Fat
Borders of the axilla (5)
Anterior = pec major and minor Medial = serratus anterior, upper three ribs and intercostals Posterior = subscapularis, teres major, lat dorsi (superior to inferior) Lateral = intertubercular (bicipital) groove of humerus, short head of biceps, coracobrachialis tendon Base = axillary fascia
Regions of brachial plexus (5)
Roots, Trunks, Divisions, Cords, Branches
Branches of lateral cord of brachial plexus (3)
Lateral pectoral nerve
Musculocutaneous nerve
Part of median nerve
Branches of medial cord of brachial plexus (5)
Medial pectoral nerve Medial cutaneous nerve of arm Medial cutaneous nerve of forearm Part of median nerve Ulnar nerve
Branches of posterior cord of brachial plexus (5)
Upper subscapular nerve Thoracodorsal nerve Lower subscapular nerve Axillary nerve Radial nerve
Where does dorsal scapular nerve arise from? (1) What does it serve? (3)
Arises from C5 root
Serves rhomboid major, rhomboid minor, levator scapulae
Where does long thoracic nerve arise from? What does it serve? (1)
Arises from C5-7
Serves serratus anterior
Where does nerve to subclavius arise from?
Upper trunk of brachial plexus (C5-6)
Where does suprascapular nerve arise from? What does it serve? (2)
Arises from upper trunk of brachial plexus (C5-6)
Serves supraspinatus and infraspinatus
What structures are at risk when surgical neck of humerus fractured? (2)
Axillary nerve
Posterior circumflex humeral artery
(both are close to surgical neck in quadrangular space)
What structure is at risk when midshaft humerus is fractured? Why?
Radial nerve
Lies in radial groove (AKA spiral groove/musculospiral groove/radial sulcus), which is midshaft, lateral, inferior to deltoid tuberosity
Where is the coronoid fossa located?
Superior to trocholea, medial to radial fossa (anterior surface of distal humerus)
Where is the radial notch located?
Lateral aspect of coronoid process (proximal ulna)
Is radial head distal or proximal?
Is head of the ulna distal or proximal?
Radial head proximal
Ulnar head distal
What inserts into the radial tuberosity?
Tendon of the biceps brachii
Where is Lister’s tubercle?
What is its function?
Distal end of radius, dorsal aspect (AKA dorsal tubercle)
Acts as pulley for EPL tendon to change direction
Subclavius muscle:
- Origin?
- Insertion?
- Function?
- Superior surface of medial end of first rib and its cartilage
- Inferior surface of middle third of clavicle
- Depresses clavicle, elevates first rib
What provides majority of stability to ACJ?
Costoclavicular ligament
What elevates the shoulder girdle?
Levator scapulae, upper fibres of trapezius
What depresses the shoulder girdle?
Lower fibres of trapezius, subclavius, lat dorsi, pec minor
What protracts the shoulder girdle?
Serratus anterior, pec minor, pec major
What retracts the shoulder girdle?
Trapezius, rhomboids major and minor
What are the origins and insertions of:
- Upper fibres of trapezius? (3,3)
- Lower fibres of trapezius? (1,1)
- Origins = External occipital protruberance, superior nuchal line, spines of cervical vertebrae
Insertions = inner border of acromium, outer third of clavicle, spine of scapula - Origins = spines of thoracic vertebrae
Insertions = medial spine of scapula
What are the origins and insertions of levator scapulae?
Origins = transverse processes C1-4 Insertions = Supero-medial angle of scapula
What are the origins and insertions of rhomboids major and minor?
Origins = spines of upper thoracic vertebrae Insertions = vertebral border of scapula
What are the origins and insertions of serratus anterior?
Origins = upper 8 ribs Insertions = vertebral border of scapula
What provides active and passive stability to the GHJ? Which is the most important?
Passive:
Glenoid labrum
Capsule thickened by 2 glenohumeral ligaments anteriorly and coracohumeral ligament superiorly
Active
Tendon of long head of biceps (from supraglenoid tubercle, through bicipital groove
Rotator cuff muscles (most important)
What are the borders of the quadrangular space? (4)
Contents? (2)
Borders: Superior = teres minor Inferior = teres major Lateral = humerus Medial = long head of triceps
Contents:
Axillary nerve
Posterior circumflex humeral artery
Which muscles flex the shoulder?
Pec major and anterior deltoid are prime movers
Biceps brachii and coracobrachialis mainly stabilise
Which muscles extend the shoulder?
Lat dorsi and posterior deltoid
Teres minor and major assist
Which muscles adduct the shoulder?
Prime = pec major, lat dorsi
Subscapularis assists
Which muscles abduct the shoulder? (4 separate stages)
First 10-15 deg = supraspinatus
10-90 deg = deltoid
>90 deg needs rotation of scapula (trapezuis and serratus anterior) and lateral rotation of humerus (subscapularis, teres major, infraspinatus)
Which muscles medially rotate the shoulder?
Pec major Lat dorsi Subscapularis Deltoid Teres Major
Which muscles laterally rotate the shoulder?
Infraspinatus
Posterior deltoid
Where does pec major originate (2 heads) and insert?
Origins: clavicular head = anterior surface of medial clavicle, sternal head = sternum and upper 6 costal cartilages
Insertion of both = lateral lip of bicipital groove
Where does latissimus dorsi originate and insert?
Origin: spines of T7-12, lumbar fascia, posterior third of iliac crest
Insertion: intertubercular groove of humerus
Where does pec minor originate and insert?
Origin: anterior ribs 3-5
Insert: coracoid process
What is the innervation of pec major?
Clavicular head: lateral pectoral nerve (C5-6)
Sternal head: medial pectoral nerve (C7-T1)
What is the innervation of lat dorsi?
Thoracodorsal nerve (from posterior cord of brachial plexus)
What does suprascapular nerve innervate?
Where does it come from?
Supraspinatus and infraspinatus
Branches from upper trunk of brachial plexus
What does the axillary nerve innervate (motor and sensory)?
Where does it come from?
Motor: deltoid, teres minor +/- long head of triceps (controversial)
Sensory: regimental patch
Branch of the posterior cord of brachial plexus
What do the two branches of the subscapular nerve innervate?
Upper branch: upper portion of subscapularis
Lower branch: lower portion of subscap, teres major
What is the origin, insertion, action and innervation of teres minor?
Origin: dorsal aspect of lateral border of scapula
Insertion: inferior of GT of humerus
Action: lateral rotation of humerus
Innervation: Axillary nerve
What is the origin, insertion, action and innervation of supraspinatus?
Origin: supraspinous fossa
Insertion: superior of GT of humerus
Action: initiates shoulder abduction
Innervation: suprascapular nerve
What is the origin, insertion, action and innervation of infraspinatus?
Origin: infraspinous fossa
Insertion: middle of GT of humerus
Action: external rotation of humerus
Innervation: suprascapular nerve
What is the origin, insertion, action and innervation of subscapularis?
Origin: subscapular fossa
Insertion: LT of humerus
Action: internal rotation and adduction of humerus
Innervation: upper lower subscapular nerves
What does the radial head articulate with?
Capitulum (humerus) and radial notch (ulna)
What are the origin, insertion, main action and innervation of biceps brachii?
Origin: short head = coracoid, long head = supraglenoid tubercle
Insertion: radial tuberosity and bicipital aponeurosis (to ulna)
Main action: elbow flexion and forearm supination
Innervation: musculocutaneous nerve (C5-7)
What are the origin, insertion, main action and innervation of brachialis?
Origin: distal half anterior humeral shaft
Insertion: ulnar tuberosity, coronoid process
Action: elbow flexion
Innervation: musculocutaneous nerve (+/- radial nerve)
What are the origin, insertion, main action and innervation of coracobrachialis?
Origin: coracoid process
Insertion: anteromedial humeral shaft distal to origin of brachialis
Action: shoulder adduction and flexion
Innervation: musculocutaneous nerve
What does the musculocutaneous nerve supply?
Motor: biceps brachii, brachialis, coracobrachialis
Sensory: lateral cutaneous nerve of forearm
What are the origin, insertion, main action and innervation of brachioradialis?
Origin: supracondylar ridge (of humerus)
Insertion: radial styloid
Action: elbow flexion
Innervation: radial nerve
What are the origin, insertion, main action and innervation of triceps brachii?
Origins: infraglenoid tubercle (long head), posterior humeral shaft above radial groove (lateral head), posterior aspect humeral shaft below radial groove (medial head)
Insertion: olecranon process
Action: elbow extension (+ extension and adduction at shoulder by long head only)
Innervation: radial nerve (+/- axillary to long head)
What is PRUJ an articulation between?
Radial head with radial notch on proximal ulna and with capitulum on distal humerus
What is DRUJ an articulation between?
Ulna head with ulnar notch on distal radius and fibrocartilaginous disc
What are the attachments of fibrocartilaginous articular disc at distal ulna?
Apex to ulnar styloid, base to ulnar notch
For pronator teres:
Origin? Insertion? Action? Innervation?
Origin: common flexor origin (medial humeral epicondyle) and coronoid process of ulna
Insertion: midshaft radius
Action: forearm pronation
Innervation: median nerve
For pronator quadratus:
Attachments? Action? Innervation?
Attachments: anterior distal radius and ulna
Action: forearm pronation
Innervaton: median nerve
Which muscles produce forearm supination? (2)
Biceps brachii
Supinator
For supinator:
Origin? (2) Insertion? Action? Innervation?
Origin: lateral epicondyle and supinator crest on ulna
Insertion: proximal radial shaft
Action: forearm supination
Innervation: radial nerve
How many forearm muscles in superficial anterior compartment? Where do they all (at least partially) originate?
4 (pronator teres, FCR, palmaris longus, FCU)
Origin = common flexor origin (medial humeral epicondyle)
Where does FCR originate, insert, what action(s), innervation?
Origin = common flexor origin (medial humeral epicondyle) Insertion = MC 2 and 3 Action = wrist flexion and abduction innervation = median nerve
For FCU:
Origin? (2) Insertion? Action? Innervation?
From common flexor origin (medial humeral epicondyle) and posterior ulna to hook of hamate and base of 5th MC (via pisiform bone)
Flexes and adducts the wrist
innervation = median nerve
Where does palmaris longus originate, insert, what action(s), innervation?
Origin: common flexor origin (medial humeral epicondyle)
Insertion: flexor retinaculum
Wrist flexion
Median nerve
How many forearm muscles in intermediate flexor compartment?
1 (FDS)
For FDS:
Origin? (3) Insertion? Action? Innervation?
Origin: 1 head from common flexor origin (medial humeral epicondyle) and coronoid process, other head from anterior oblique line of radius
Insertion: 4 tendons - one for base of middle phalanges of each finger
Actions: wrist flexion, finger MCPJ and PIPJ flexion
Innervation: median nerve
How many forearm muscles in deep flexor compartment?
3 (FDP, FPL, pronator quadratus)