The shoulder and arms (B) Flashcards
Which muscles make up the intrinsic shoulder muscle compartment?
Rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis)
Teres major
Deltoid
Describe the attachments of deltoid.
Proximal – lateral 1/3 of the clavicle (deltoid tubercle of clavicle), acromion process and crest of the spine of the scapula (deltoid tubercle of spine of scapula)
Distal – deltoid tuberosity of the humerus
Which nerve supplies the deltoid and what movement is it responsible for?
Axillary nerve
It is responsible for abduction of the arm
Describe the attachment of the rotator cuff muscles and state the nerves that innervate them. Supraspinatus Infraspinatus Teres minor Subscapularis
Supraspinatus-
Supraspinatus fossa to greater tubercle of the humerus (look on 3D anatomy)
Innervated by suprascapular nerve
Infraspinatus - infraspinatus fossa to greater tubercle of humerus
Innervated by suprascapular nerve
Teres minor - lateral border of the scapula to the greater tubercle
Innervated by the axillary nerve
Subscapularis - Subscapular fossa to the lesser tubercle
Innervated by the subscapular nerve
NOTE; THE FIRST 3 MUSCLES HAVE A ROLE IN EXTERNAL ROTATION, HENCE THEY ATTACH TO THE GREATER TUBERCLE (imagine the rotation when it contracts). Subscapularis is involved in internal rotation and hence attaches to the lesser tubercle of the humeruss
Which rotator cuff muscle is important for abducting the arm?
Supraspinatus is important in the first 15 degree of abduction of the arm, then the deltoid takes over.
Describe the attachments of teres major.
Inferior angle of the scapula to the medial lip of the intertubercular sulcus
Medial lip is different to lesser tuberosity of the humerus. Medial Lip refers to the medial ‘edge’ of the groove from top to bottom of the sulcus. Lesser tuberosity is only a small circular bit at the top of the humerus (search up a pic)
Which nerve innervates teres major?
Lower subscapular nerve
Which muscles make up the anterior compartment of the arm and which nerve innervates them?
Biceps brachii
Brachialis
Coracobrachialis
Innervated by: musculocutaneous nerve
Describe the attachments of biceps brachii.
Long head – supraglenoid tubercle
Short head – coracoid process
Distal attachment – radial tuberosity
long head of biceps - supraglenoid tubercle
long head of triceps - infraglenoid tubercle
Describe the attachments of coracobrachialis.
Proximal: coracoid process
Distal: anteromedial surface of the shaft of the humerus
Describe the attachments of brachialis.
Proximal: shaft of the humerus
Distal: coronoid process of ulna
Which muscles make up the posterior compartment of the arm?
Triceps Anconeus (ancon=elbow)
What are the attachments of the triceps?
Long head – infraglenoid tubercle
Medial and lateral head – proximal part of the shaft of the humerus
Distal attachment: olecranon process of the ulna
What are the attachments of anconeus?
Proximal: lateral epicondyle of the humerus
Distal: shaft of the ulna
Which nerve innervates the posterior compartment of the arm?
Radial nerve
Which four joints make up the pectoral girdle?
Sternoclavicular
Acromioclavicular
Gleno-humeral
Scapulo-thoracic (sometimes referred to as a ‘virtual’ or ‘physiological’ joint)
Which two ligaments make up the coracoclavicular ligament?
Conoid ligament
Trapezoid ligament
Which three ligaments surround the glenohumeral joint?
Glenohumeral ligament
Coracohumeral ligament
Transverse humeral ligament
What is the ligament of the acromioclavicular joint?
Acromioclavicular ligament
What type of joint is the glenohumeral joint?
Ball-in-socket synovial joint
What is the glenoid cavity deepened by?
Glenoid Labrum (lip) – fibrocartilaginous collar
What structure is found between the superior surface of the humerus and the inferior surface of the acromion?
Subacromial bursa
what is the main function of the rotator cuff muscles?
Main function is to stabilise the humeral head within the glenoid
Also, the rotator cuff depresses the humeral head.
Individual muscles of the rotator cuff are involved in abducting the humerus and external/internal rotation (external rotation=rotate away from midline, internal = towards midline)
What are the movements of the scapula-thoracic joint?
Elevation/depression
Protraction/retraction
Rotation
What is the shape of the axilla?
Pyramid
What does the axilla contain?
Nerves – the brachial plexus
Arteries – axillary artery and its branches
Veins – axillary vein and its branches
Lymphatic vessels and lymph nodes
What are the four walls of the axilla?
Anterior wall – pectoralis major and pectoralis minor, subclavius
Lateral wall – humerus (intertubercular sulcus)
Medial wall – upper thoracic wall and serratus anterior
Posterior wall – costal surface of scapula, subscapularis muscle, teres major and distal part of latissimus dorsi
Describe the divisions of the subclavian artery as it passes into the axilla and down the arm.
As the subclavian artery passes over the first rib it becomes the axillary artery
The axillary artery then becomes the brachial artery as it passes the inferior border of teres major
The brachial artery has an important branch - profundi brachii
Brachial artery then divides into radial and ulnar arteries at the level of the elbow
Which branch of the axillary artery goes around the humerus?
Circumflex humeral artery
Describe the superficial venous anatomy of the arm.
There are two main SUPERFICIAL veins: cephalic (lateral) and basilic (medial)
Above the elbow, the basilic vein joins the brachial vein (part of the DEEP venous drainage, brachial veins are venae comitantes surrounding around the brachial artery) to form the axillary vein of the arm
Further higher up the axillary vein, the cephalic vein later drains into the axillary vein more superiorly
Note: below the elbow (in forearm), the brachial veins venae comitantes split into radial and ulnar veins (deep venous system)
ie: superficial drianage: cephalic and basilic veins
deep drainage (these are all venae comitantes) of UPPER LIMB (not just arm): (from distal to proximal) radial and ulnar vein join to form brachial vein, this then joins the basilic vein ie superficial drainage system above the elbow to form the axillary vein. Eventually, cephalic vein joins the axillary vein
Which small vein joins the cephalic and basilic veins in the cubital fossa?
Median cubital vein
What are the veins on the dorsal side of the hand called?
What are the two venous arches that drains the palms?
Dorsal venous network , this drains to cephalic and basilic veins (the superficial venous system)
Arches that drain the palm:
Superficial palmar venous arch- drains to ulnar vein
Deep palmar venous arch - drains radial vein
these are both venae comitantes that accompany the superficial and deep palmar arches (the artery equivalent)
Describe the arrangement of the deep veins of the arm.
They follow the arteries back as venae comitantes deep drainage (these are all venae comitantes): (from distal to proximal) radial and ulnar vein join to form brachial vein at around the elbow joint (this is NOT the venous drainage of the arm but FOREARM), this then joins the basilic vein ie superficial drainage system above the elbow to form the axillary vein. Eventually, cephalic vein joins the axillary vein
What are the groups of lymph nodes found in the shoulder and arm?
Cubital lymph nodes
Delto-pectoral lymph nodes
Axillary lymph nodes
Which two nerves are found near the axillary lymph nodes?
Long thoracic nerve
Thoraco-dorsal nerve
What are the five groups of axillary lymph nodes?
Apical Central Pectoral Subscapular Humeral
What are the five parts of the brachial plexus?
Roots Trunks Divisions Cords Branches
What are the five largest nerves of the brachial plexus?
Musculocutaneous Axillary Radial Median Ulnar
