ANATOMY: Upper Limb 2

Superior, middle, and inferior glenohumeral ligaments

3 ligaments span the anterior surface of the joint (from the anterior surface of the neck of the scapula to the lesser tubercle of the humerus) 1. Superior glenohumeral ligament 2. Middle glenohumeral ligament 3. Inferior glenohumeral ligament

Glenoid fossa

An ovoid articular surface on the lateral surface of the scapula Smooth surface which articulates with the head of the humerus to form the glenohumeral joint

Ligaments of the radioulnar joint

Annular ligament

Three components of the ulnar collateral ligament

Anterior band (Medial epicondyle--> coronoid process) Posterior band (Medial epicondyle--> olecranon process) Oblique band (Olecranon process--> coronoid process)

Greater tubercle of the humerus

Antero-lateral muscle attachment site immediately distal to the neck

Action of Coracobrachialis muscle

Assists in flexion and adduction of the arm at the shoulder joint

Joint capsule of the glenohumeral joint

Attaches to the anatomical neck of the humerus, the outer margin of the glenoid labrum and the base of the coracoid process medially. Wraps around the axillary recess

Transverse humeral ligament

Attaches to the lesser and greater tubercles, spanning the intertubercular groove

Annular ligament

Attaches to the superior margin of the radial notch (anterior surface of ulna) , loops around the head and neck of the radius, then attaches to the inferior margin of the radial notch (posterior surface of ulna)

Triangular space

BORDERS Superior - Teres minor Inferior - Teres major Lateral - Long head of triceps brachii Portal for the SCAPULAR CIRCUMFLEX ARTERY

Triangular Interval

BORDERS Superior - teres major Medial - long head of triceps brachii Lateral - humeral shaft Portal for the RADIAL NERVE and the PROFUNDA BRACHII ARTERY

Quadrangular space

BORDERS Superior- Teres Minor Inferior- Teres Major Lateral- Humeral shaft Medial- Long head triceps brachii Portal for the AXILLARY NERVE and POSTERIOR HUMERAL CIRCUMFLEX ARTERY

Deltoid tuberosity

Bone development on the proximal lateral surface of the humerus Insertion site of deltoid

What is the deep fascia of the arm called?

Brachial fascia

Intertubercular (Bicipital) Groove

Deep furrow which separates the greater and lesser tubercle

Lateral epicondyle

Distal end of the humerus flares laterally Roughened muscle attachment sites

Medial epicondyle

Distal end of the humerus flares medially Roughened muscle attachment sites

Axillary recess

Expansion of synovial membrane inferiorly

Action of aconeus muscle

Exstension of forearm Stabilizes the elbow joint and joint capsule.

Radial Groove

Extends obliquely along the posterolateral surface of the humerus, between the origins of the lateral and medial heads of Triceps brachii. Difficult to locate/ absent on many humeri.

Lateral intermuscular septum

Extension of deep fascia to lateral portion of humerus Runs from lateral epicondyle/lateral supracondylar ridge to the deltoid tuberosity

Medial intermuscular septum

Extension of deep fascia to medial portion of humerus Runs from medial epicondyle/medial supracondylar ridge to the medial lip of the intertubercular groove (insertion site of teres major muscle)

Glenohumeral joint movement

Flexion, extension, hyperextension, abduction, adduction, internal (medial) rotation, external (lateral) rotation, circumduction

The rotator cuff

Fusion of the tendons of the four muscles that span the glenohumeral joint (subscapularis, supraspinatus, infraspinatus, and teres minor) with the deeper joint capsule. Thickest anteriorly (due to the glenohumeral ligaments) and thinnest posteriorly

Synovial membrane and joint capsule of the elbow

HUMERUS: Anchored to the olecranon fossa on the posterior surface, and the radial and coronoid fossae on the anterior surface. RADIUS: Anchored to the neck of the radius ULNA: Anchored to the coronoid process of the ulna, and the anterior surface of the olecranon

3 components of the proximal end of the radius

Head Neck (Bicipital) tuberosity of the radius

Pronation and supination (elbow)

Head of radius rotates against radial notch of ulna (medially) and capitulum of humerus (proximally)

The three joints of the elbow

Humerus-ulna, humerus-radius, and proximal radius-proximal ulna ALL JOINTS SHARE A COMMON SYNOVIAL MEMBRANE AND JOINT CAPSULE

Triceps brachii

Large, three-headed muscle Sole muscle in posterior compartment of arm

Nutrient foramen

Located on the medial surface of the shaft Allows passage of Nutrient artery to the diaphysis of the humerus

Infraglenoid Tuberosity

Muscle attachment site located immediately inferior to the glenoid fossa

Supraglenoid Tuberosity

Muscle attachment site located immediately superior to the glenoid fossa

Coracobrachialis muscle

O: Coracoid process of scapula I: Medial surface of mid-humerus N: Musculocutaneous branch A: Brachial artery

Brachialis muscle

O: Distal half of the anterior surface of the humerus (insertion site of Coracobrachialis ) I: Ulnar tuberosity and coronoid process of the ulna N: Musculocutaneous nerve A: Radial recurrent artery

Long head of triceps brachii

O: Infraglenoid tubercle of scapula I: Olecranon process of the ulna (single tendon) N: Radial nerve A: Profunda brachii (deep brachial) artery NEVER TOUCH THE HUMERUS

Aconeus muscle

O: Lateral epicondyle (Posterior) I: Lateral olecranon N: Radial Nerve A: Profunda brachii artery and Recurrent interosseus artery

Lateral head of triceps brachii

O: Posterior humeral shaft I: Olecranon process of the ulna (single tendon) N: Radial nerve A: Profunda brachii (deep brachial) artery

Medial head of triceps brachii

O: Posterior humeral shaft I: Olecranon process of the ulna (single tendon) N: Radial nerve A: Profunda brachii (deep brachial) artery

Biceps brachii

O: Short head- coracoid process of the scapula O: Long head- Supraglenoid tubercle of scapula I: Tendon: Bicipital tuberosity of the radius I: Aponeurosis (flattened tendon): merges with the antebrachial fascia (deep fascia) N: Musculocutaneous nerve A: Brachial artery

5 components of the proximal end of the ulna

Olecranon process Trochlear notch Coronoid process Radial notch Tuberosity of the ulna

Radial collateral ligament

Originates from the lateral epicondyle of the humerus then fans out and integrates into the annular ligament

Action of Brachialis muscle

PRIMARY flexor of elbow

Actions of Biceps brachii

PRIMARY supinator Flexor of elbow Assists in flexing and abducting the the glenohumeral joint

Lesser tubercle of the humerus

Postero-medial muscle attachment site immediately distal to the neck

Trochlear groove

Prominent spines of bone which form the lateral and medial borders of the trochlea The broders create the trochlear groove

Pronation and supination

Pronation: palms down Supination: palms up

Bicipitoradial bursa

Protects the tendon against abrasion from the tuberosity

Subtendinous olecranon bursa

Protects the tendon of triceps brachii from the rough surface of the olecranon.

Olecranon Fossa

Proximal to the trochlea on the posterior surface of the humerus

Brachial fascia

Proximally continuation of the pectoral, deltoid, and axillary fasciae Distally is continued by the antebrachial fascia

3 muscular landmarks for arteries and nerves of the axilla

Quadrangular space Triangular space Triangular interval

Ligaments of the humeroradial joint

Radial collateral ligament

Anatomical neck of the humerus

Separates the head from the remainder of the humerus

Supinator crest

Space between the radius and ulna Forms closer to the olecranon process

Interosseous crest

Space between the radius and ulna Forms further from the olecranon process

Coracohumeral ligament

Spans from the base of the coracoid process along the superior surface of the glenohumeral joint to the greater tubercle

Ulnar collateral ligament

Spans from the medial epicondyle of the humerus to the coronoid process and olecranon Made up of 3 components

3 large bursa associated with the shoulder joint

Subacromial bursa Subdeltoid bursa Subtendinous bursa of the subscapularis

Anterior muscles crossing the glenohumeral joint

Subscapularis Pectoralis major

The arm is covered by a generalized _______________ with variable amounts of __________________.

Superficial fascia Adipose tissue

Superior muscles crossing the glenohumeral joint

Suprspinatus Deltoid

Lateral supracondylar ridge

Tapering from the lateral epicondyle proximally toward the shaft of the humerus

Medial supracondylar ridge

Tapering from the medial epicondyle proximally toward the shaft of the humerus

Supratrochlear Foramen

The coronoid and olecranon fossa may be deep enough to perforate the humerus and form the supratrochlear foramen

Joint capsule and ligaments

The joint capsule is reinforced by 4 extracapsular ligaments. Ligaments span from the base of the coracoid process along the superior surface of the glenohumeral joint to the greater tubercle

Synovial membrane and the biceps tendon

The synovial membrane extends along the biceps tendon (inserts onto supraglenoid tuberosity) all the way into the intertubercular groove Forms lubricating sheath around the tendon, which prevents it from abrading against the bone

Two condyles between the medial and lateral epicondyles

Trochlea (medial) Capitulum (smaller, lateral)

Flexion of elbow

Trochlear notch of ulna rotates around trochlea of humerus while head of radius rotates over the capitulum of humerus Anterior surface of coronoid process of ulna contacts coronoid fossa of humerus Anterior surface of head of radius contacts radial fossa of humerus

Extension of the elbow

Trochlear notch of ulna rotates around trochlea of humerus while head of radius rotates over the capitulum of humerus Anterior surface of olecranon process of ulna contacts olecranon fossa of humerus.

Glenoid labrum

A rim of fibrocartilage around the glenoid fossa

Synovial membrane of the glenohumeral joint

Anchored by glenoid labrum and the anatomical neck of the humerus

The superficial fascia serves as a conduit for which two large superficial veins?

Cephalic vein Basilic vein

Importance of medial and lateral intermuscular septae

Divide the arm into anterior (flexor) and posterior (extensor) compartments

Posterior muscles crossing the glenohumeral joint

Infraspinatus Teres minor Teres major Latissimus dorsi

Lateral and medial lips of the intertubercular groove

Intertubercular groove extends distally beyond the tubercles The groove is bordered by two low roughened muscle attachment sites termed the lateral and medial lips of the intertubercular groove

Head of humerus

Located on the proximal end of the humerus Smooth surface which articulates with the glenoid fossa to form the glenohumeral joint

Rotator cuff injury

Majority of rotator cuff injuries involve damage to the supraspinatus Caused by repeated overhead movements of the arm or excessive force application while the arms are in an elevated position

Radial Fossa

Proximal to the capitulum on the anterior surface of the humerus

Coronoid Fossa

Proximal to the trochlea on the anterior surface of the humerus

Synovial joint

Synovial joints are surrounded by a synovial membrane, which is then surrounded by the thicker joint capsule Joint capsules limit rotation of a joint

Nutrient Artery

The nutrient artery, a branch from the Brachial Artery, passes through the foramen to supply the diaphysis of the humerus

Ligaments of the humeroulnar joint

Ulnar collateral ligament

Pronation and supination (wrist)

Ulnar notch of radius traverses the smooth rounded surface of head of ulna