Upper limb (shoulders and axilla) Flashcards
What are the features of the clavicle?
Sternal end: - Sternal facet - Impression for the costoclavicular ligament Acromion end: - Acromial facet - Trapezoid line - Conoid tubercle
What are the features of anterior aspects of the scapula?
- Subscapular fossa
- Acromion
- Coracoid process
What are the features of the posterior aspects of the scapula?
- Supraglenoid fossa
- Spine of scapula
- Infraglenoid fossa
What are the features of the edges of the scapula?
- Inferior angle
- Lateral border
- Infraglenoid tubercle
- Glenoid fossa
- Supraglenoid tubercle
- Suprascapular notch
- Superior border
- Superior angle
- Medial border
What are the joints associated with the pectoral girdle?
- Glenohumeral joint
- Acromioclavicular joint
- Sternoclavicular joint
- Scapulothoracic articulation (physiological joint)
What type of joint is the sternoclavicular joint
- Atypical synovial joint
- Divided into 2 compartments by fibrocartilaginous articular disc
What movements occur at the sternoclavicular joint?
- Movements in anterior-posterior plane
- Movements in vertical plane
- Rotation of the clavicle by 40∘
What are the ligaments of the sternoclavicular joint?
- Anterior and posterior sternoclavicular ligaments
- Interclavicular ligament: Links 2 clavicles to superior border of clavicle
- Costoclavicular ligament: Links clavicle to 1st rib and costal cartilage
What type of joint is the glenohumeral joint?
Synovial ball-and-socket joint
What are the ligaments associated with the the glenohumeral joint?
- Coraco-acromial ligament: Links coracoid process to acromion
- Coracohumeral joint: Links the greater tubercle of humerus to the coracoid process
- Superior/middle/inferior: Links the margins of the glenoid cavity to the lesser tubercle/anatomical neck of humerus
What are the muscles associated with the glenohumeral joint (posterior-anterior)?
- Teres minor
- Infraspinatus
- Supraspinatus
- Subscapularis
- (rotator cuff muscles)
What are the bursae associated with glenohumeral joint?
- Subacromial (inks to subdeltoid) bursa
- Subscapular bursa
What are the movements associated with the shoulder joint?
- Flexion
- Extension
- Abduction: Supraspinatus (0-15∘) and deltoid (15-120∘)
- Adduction: Coracobrachialis (with pec. major, latissimus dorsi, teres major)
- Medial rotation: Subscapularis, teres major, pec. major, latissimus dorsi
- Lateral rotation: Infraspinatus, teres minor
- Circumduction
What type of joint is the acromioclavicular joint?
Synovial joint
What are the ligaments associated with the acromioclavicular joint?
- Acromioclavicular ligament
- Trapezoid
- Conoid
What are the movements associated with the acromioclavicular joint?
- Movement in anterior-posterior plane
- Movement in vertical plane
- Rotation
- Movements needed for rotation of the scapula
What are the margins of the suprascapular foraman?
- Suprascapular notch
- Superior transverse scapular ligament
What are the movements (of the scapula) associated with the scapulothoracic articulation?
- Elevation
- Depression
- Protraction
- Retraction
- Upwards rotation
- Downwards rotation
What are the margins of the axilla?
Anterior wall: - Pectoralis major - Pectoralis minor - Subclavius - Clavipectoral fascia Posterior wall: - Subscapularis - Teres major - Tendons of latissimus dorsi Medial wall: - Serratus anterior Lateral wall: - Intertubercular sulcus (humerus) Floor: - Deep fascia and skin of the armpit
What are the contents of the axilla?
- Axillary artery
- Axillary vein
- Brachial plexus (cords)
- Axillary lymph nodes
Where does the subclavian artery become the axillary artery?
Inferior border of 1st rib
What are the boundaries of the 3 sections of the axillary artery?
- Between the inferior border of 1st rib and the superior border of pec. minor.
- Between the superior and inferior borders of pec. minor.
- Between the inferior border of pec. minor and the inferior margin of teres major.
What are the branches of the axillary artery?
- Superior thoracic artery: Supplies medial and anterior thoracic walls.
- Thoraco-acromial artery: Supplies the anterior axillay wall.
- Lateral thoracic artery: Supplies the anterior/medial axillary walls and breast.
- Subscapular artery: Supplies the posterior axillary wall.
- Anterior/posterior circumflex arteries: Supplies the glenohumeral joint.
What is the mnemonic for the arteries of the axillary artery?
Some Times Life Seems A Pain
Where does the axillary artery become the brachial artery?
Inferior border of teres major
What are the lymph nodes associated with the axilla?
Humeral (lateral) nodes: Drains most of upper limb.
Pectoral (anterior) nodes: Drains the abdominal wall, chest wall and breasts.
Subscapular (posterior) nodes: Drains back, shoulder and neck.
Central nodes: Drains the anterior, posterior and lateral nodes.
Apical nodes: Receives lymph from all other nodes.
What are the apertures on the posterior axillary wall?
Quadrangular space: - Axillary nerve - Posterior circumflex humeral artery Triangular space: - Circumflex scapular artery Triangular interval: - Radial nerve - Profunda brachii artery
From which roots do the trunks of the brachial plexus form?
- Upper trunk: C5, C6
- Middle trunk: C7
- Lower trunk: C8, T1
From which divisions do the cords of the brachial plexus form?
- Lateral cord: Anterior divisions of upper and middle trunks.
- Posterior cord: Posterior divisions of all 3 trunks.
- Medial cord: Anterior division of lower trunk.
What are the branches associated with the roots of the brachial plexus?
- Dorsal scapular nerve (C5)
- Nerve to subclavius (C5, C6)
- Long thoracic nerve (C5, C6, C7)
What is the branch associated with the upper trunk?
Suprascapular nerve (C5, C6)
What are the branches of the medial cord?
- Medial pectoral nerve (C8, T1)
- Medial cutaneous nerve of the arm (T1)
- Medial cutaneous nerve of the forearm (C8, T1)
- Medial head of median nerve
What are the branches of the posterior cord?
- Upper subscapular nerve (C6)
- Thoracodorsal nerve (C6, C7, C8)
- Lower subscapular nerve (C6, C7)
- Axillary nerve (C5, C6)
- Radial nerve (C5-T1)
What are the branches of the lateral cord?
- Lateral pectoral nerve (C5, C6, C7)
- Musculocutaneous nerve
- Lateral head of median nerve
What is the main function of the brachial plexus?
To allow for mixing of the nerves from different roots to mix.
What are the anatomical variations of the brachial plexus?
- Prefix: C4 contributes instead of T1.
- Postfix: T2 contributes instead of C5.
What are the advantages of the brachial plexus?
- Allows muscles that have similar functions but different dermatomes to be innervated by the same nerves. This allows synergistic movements to be much easier.
- Allows muscles that have seemingly different functions to be innervated by the same nerve to allow for synergistic movements.
- Allows anaesthetics to be administered much more easily.
- Allows nerves of upper limb to be distributed in fewer branches.
What are the disadvantages of the brachial plexus?
- Mobility of the arms mean that the roots and trunks may be damaged by traction.
- Damaging one spinal nerve/root causes widespread functional loss in the upper limb due to its different distributions as a result of mixing in brachial plexus.
- Difficult to determine whether loss of sensation to skin due to damage to spinal nerve or peripheral nerve.
What is Erb’s palsey and what are the clinical signs?
- Injury to the upper trunk of brachial plexus.
- Causes ‘waiter’s tip’.
What is Klumpke’s paralysis and what are the clinical signs?
- Injury to the lower trunk of the brachial plexus.
- Causes ‘clawed hand’.
