The shoulder and arms Flashcards
What are the two main processes coming off the scapula?
Coracoid process
Acromion process
What are the differences between the anatomical and surgical necks of the humerus?
Anatomical – between the head of the humerus and everything else
Surgical – the main narrowing of the distal humerus – it is the most common site for fractures of the humerus
What are the three fossae of the scapula?
Supraspinous
Infraspinous
Subscapular
Which part of the scapula articulates with the humerus?
Glenoid cavity
On which bones are deltoid tubercles found?
Spine of the scapula
Humerus
What is the name given to the distinctive notch on the scapula?
Suprascapular notch
What is the name given to the groove between the greater and lesser tubercles of the humerus?
Intertubercular sulcus (bicipital groove)
What are the two distinctive protrusions on the lateral third of the clavicle and what are their roles?
Conoid tubercle
Trapezoid line
They are the point of attachment of the conoid ligament and trapezoid ligament (both part of the coracoclavicular ligament)
What are the names of the three fossae at the distal end of the humerus?
Anterior – coronoid and radial fossae
Posterior – olecranon fossa
What are the names given to the two ridges on either side of the distal end of the humerus?
Medial supracondylar ridge
Lateral supracondylar ridge
What are the five muscle compartments of the region?
Anterior pectoral Posterior pectoral Intrinsic shoulder Anterior compartment of arm Posterior compartment of arm
Which muscles make up the anterior pectoral compartment?
Pectoralis major
Pectoralis minor
Serratus anterior
Subclavius
What are the attachments of pectoralis major?
Medial 1/2 of the clavicle + sternum + part of costal margin
Lateral lip of intertubercular sulcus
What are the actions of pectoralis major?
Adducts and medially rotates the shoulder
Which nerve innervates pectoralis major?
Lateral pectoral nerve
What are the attachments of pectoralis minor?
Ribs 2-5
Coracoid process
Which nerve innervates pectoralis minor?
Medial pectoral nerve
What are the attachments of subclavius?
1st costochondral joint
Clavicle
Which nerve innervates subclavius?
Subclavian nerve
What are the attachments of serratus anterior?
Medial border of the costal surface of the scapula
Anteriorly attaches to the ribs (1-9)
Which nerve innervates serratus anterior?
Long-thoracic nerve
What can damage to this nerve cause?
Winging of the scapula
Which muscles make up the posterior pectoral compartment?
Trapezius
Latissimus dorsi
Levator scapulae
Rhomboids (minor and major)
What is the motor supply to trapezius?
Accessory nerve (CN XI)
Describe the attachments of latissimus dorsi.
Thoracolumbar fascia and posterior 1/3 of the iliac crest
Floor of the intertubercular sulcus
Which nerve innervates latissimus dorsi?
Thoraco-dorsal nerve
What movement is latissimus dorsi responsible for?
Extends, adducts and rotates the humerus
Describe the attachments of the rhomboids.
Both attach distally to the medial border of the scapula
Rhomboid minor attaches proximally to the spinous processes of C7 and T1
Rhomboid major attaches proximally to the spinous processes of T2-T5
Which nerve supplies the rhomboids?
Dorsal scapular nerve
What movement are the rhomboids responsible for?
Retracts, rotates and fixes the scapula
Describe the attachments of levator scapulae.
Attaches proximally to the transverse processes of C1-C4
Attaches distally to the superior angle of the scapula
Which nerve innervates levator scapulae?
Dorsal scapular nerve (and C3 + C4)
What movements are levator scapulae responsible for?
Elevates and rotates the scapula
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, acromion process and crest of the spine of the 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-
Suprascapular fossa to greater tubercle
Innervated by suprascapular nerve
Infraspinatus - Infrascular fossa to greater tubercle
Innervated by suprascapular nerve
Teres minor - Upper 2/3 of the lateral margin of the scapula to the greater tubercle
Innervated by the axillary nerve
Subscapularis - Subscapular fossa to the lesser tubercle
Innervated by the subscapular nerve
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
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
Describe the attachments of coracobrachialis.
Proximal: coracoid process
Distal: front 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
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 (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 – fibrocartilaginous collar
What structure is found between the superior surface of the humerus and the inferior surface of the acromion?
Subacromial bursa
What does the rotator cuff do to the humeral head?
Depresses the humeral head and holds it within the glenoid cavity
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?
Apex – between the first rib, clavicle and superior border of subscapularis
Floor – skin, subcutaneous tissue and fascia extending from the arm to the chest
Anterior wall – pectoralis major and pectoralis minor
Lateral wall – humerus
Medial wall – upper thoracic wall and serratus anterior
Posterior wall – scapula/subscapularis, teres minor and 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 is are two main superficial veins: cephalic (lateral) and basilic (medial)
Above the elbow the basilic artery joins the venae comitantes of the brachial artery to form the axillary vein
The cephalic vein drains into the axillary vein more superiorly
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?
Dorsal venous network
Describe the arrangement of the deep veins of the arm.
They follow the arteries back
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