2. The Shoulder and Upper Arm Flashcards
Recall the 3 fossae of the scapular and their relative positioning
Anterior: Supraspinous (above spine) and infrapinous (below spine)
Posterior: suprascapular
Where do the scapula and the clavicle articulate?
At the acromion
In an anterior view of the clavicle, in which direction is it bent?
Medial 2/3 are bent anteriorly and the lateral 1/3 is bent posteriorly
Describe the positioning of the deltoid tubercle
Inferior side of acromial (lateral) end of clavicle
Where does the costoclavicular ligament attach to the clavicle?
At the coronoid tubercle
Where does the humerus articulate with the scapula?
Glenoid cavity
Describe the location of the greater and lesser tubercles of the humerus in an anterior view
Greater = lateral, lesser = fairly midline
Where does the deltoid muscle insert on the humerus, and with what structure is this continuous?
Deltoid tuberosity
Intertubercular line
Recall the points of articulation of the ulna and radius with the humerus
Ulna = trochlea, olecranon fossa Radius = capitulum
Recall the 4 compartments of muscles that attach to the pectoral girdle
Anterior and posterior pectoral girdle
Anterior and posterior compartments of the upper arm
Recall the muscles of the anterior pectoral girdle compartment
Pec major
Pec minor
Subclavius
Serratus anterior
Recall the proximal and distal attachments of pec major
PA: Clavicular head and sternum
DA: Lat. bicipital groove and greater tubercle
Recall the nerve supply of pec major
Medial and lateral pectoral nerves
What is the main function of pec major?
Extension and internal rotation = punching
Recall the muscles attaching to the medial and lateral lip of the bicipital/ intertubercular groove
Medial = teres major Lateral = pec major
Which nerve supplies serratus anterior?
Long thoracic
Recall the muscles of the posterior compartment of the pectoral girdle
Trapezius
Lat. dorsi
Levator scapulae
Rhomboids
Recall the innervation of trapezius
CNXI, C3/4
Recall the functions of each head of the trapezius
Upper: elevate soulder + extend head
Middle: abduct and stabilise scapula
Lower: depress scapula
Recall the innervation of lat dorsi, and its main function
Thoracodorsal nerve
Major actions on humerus
What is the function of the rhomboids?
Attach to medial scapula to stabilise and retract it
Recall the medial attachments of lat dorsi
T8 to pelvic region
Recall the muscles of the anterior compartment of the upper arm
Biceps brachii
Brachialis
Coracobrachialis
Recall the innervation of the anterior compartment of the upper arm
Musculocutaneous
Recall the origins of each head of the biceps brachii
Short head = coracoid process
Long head = supraglenoid tubercle
What is the distal attachment of the biceps brachii?
Radial tuberosity
Recall the attachments of brachialis
PA: anterior humerus
DA: ulnar tuberosty
What is the function of coracobrachilais?
Shoulder flexion and adduction
Recall the muscles that attach to the coracoid process
Short head of biceps brachii
Coracobrachialis
Pec minor
Recall the main function of brachialis
Flexion of elbow
Recall the muscles of the posterior compartment of the upper arm
Triceps brachii
Anconeus
Recall the attachments of triceps brachii
PA: medial and lateral heads attach to posterior humerus, long head attaches to infraglenoid tubercle
DA: olecranon
Recall the attachments of anconeus
PA: lateral epicondyle
DA: lateral olecranon
Recall the innervation of the posterior compartment of the upper arm
Radial nerve
What is the main muscle involved in elbow extension?
Anconeus
Recall the intrinsic shoulder muscles
Deltoid
Teres major
Rotator cuff
Recall the muscles of the rotator cuff
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Recall the innervation of the intrinsic shoulder muscles
Axillary and subscapular nerves
Recall the function of the rotator cuff muscles
Hold humerus within glenoid
Depress humerus head
Recall the function of teres major
Adduction and internal rotation
Which joint of the pectoral girdle is “virtual”?
Scapulo-thoracic
Describe the shape of the glenoid fossa
Shallow, deepened by the cartilaginous labrum
What is the glenoid labrum?
Fibro-cartilaginous rim of glenoid cavity
What is a bursa of a joint?
Capsule of enclosed synovial fluid
Recall the ligaments that are vulnerable to tear causing shoulder disloation, and the consequences of tearing each example
Ligaments of acromioclavicular joint:
Acromioclavicular ligament tear –> minor dislocation
Coracoclavicular ligament –> if you tear this in addition to AC ligament = major dislocation
Recall the components of each wall of the axilla
Anterior wall = pec major and minor
Medial wall = serratus anterior and rib 4
Posterior wall = subscapularis, teres major, lat dorsi, scapula
Recall the route and branches of the subclavian artery
Loops under clavicle –> axillary arteryq
Medial to gleno-humeral joint
Circumflex branches wind around humerus
Becomes brachial artery at inferior border of teres
Profunda brachii branches posteriorly
At elbow bifurcates into ulnar and radial
Recall the superficial limbs draining the arm
Cephalic (lateral)
Basilic (medial)
Recall the deep venous drainage of the arm
Axillary vein
Subclavian vein
Recall the course of the cephalic vein
Lateral border of arm –> joins axillary vein at axilla –> at 1st rib becomes subclavian vein
Recall 4 key sets of lymph nodes draining the arm
Axillary
Surascapular
Cubital
Delto-pectoral
