The shoulder and arms Flashcards
What are the two main processes coming off the scapula?
Coracoid process (anterior- hook) Acromion process (posterior- at lateral end of spine)
What are the differences between the anatomical and surgical necks of the humerus?
Anatomical: between head of humerus + everything else
Surgical: main narrowing of proximal humerus= most common site for fractures of the humerus
What are the three fossae of the scapula?
Supraspinous
Infraspinous
Subscapular (anterior)
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
What are the 2 distinctive protrusions on the lateral third of the clavicle and what are their roles?
Conoid tubercle
Trapezoid line
= point of attachment of the conoid ligament + trapezoid ligament (both part of the coracoclavicular ligament)
What are the names of the 3 fossae at the distal end of the humerus?
Anterior: coronoid + radial fossae
Posterior: olecranon fossa
What are the names given to the 2 ridges on either side of the distal end of the humerus?
Medial supracondylar ridge
Lateral supracondylar ridge
What are the 5 muscle compartments of the region?
Anterior pectoral girdle muscles Posterior pectoral girdle muscles Intrinsic shoulder muscles Anterior compartment of the upper arm Posterior compartment of the upper arm
Which muscles make up the anterior pectoral compartment?
Pectoralis major
Pectoralis minor
Subclavius
Serratus anterior (runs between anterior + posterior)
What are the attachments of pectoralis major?
Medial 1/3 of the clavicle + sternum + costal cartilages
Lateral lip of intertubercular sulcus
What are the actions of pectoralis major?
Adducts + medially rotates the humerus
Which nerves innervates pectoralis major?
Lateral + medial pectoral nerves
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 costal surface of the scapula
Anteriorly attaches to ribs 1-9
Which nerve innervates serratus anterior?
Long-thoracic nerve
What is the function of serrates anterior? Thus what can damage to the long thoracic nerve cause?
Holds scapula onto thoracic wall
Winging of the scapula
Which muscles make up the posterior pectoral compartment?
Trapezius
Latissimus dorsi
Levator scapulae
Rhomboids (minor + major)
What is the motor supply to trapezius?
Spinal accessory nerve (CN XI)
Describe the attachments of latissimus dorsi.
Thoracolumbar fascia + posterior 1/3 of the iliac crest
Floor of the intertubercular groove of humerus
Which nerve innervates latissimus dorsi?
What movement is latissimus dorsi responsible for?
Thoraco-dorsal nerve
Extends, adducts + rotates the humerus
Describe the attachments of the rhomboids.
Both attach distally to the medial border of scapula
Rhomboid minor attaches proximally to the spinous processes of C7 + T1
Rhomboid major attaches proximally to the spinous processes of T2-T5
Which nerve supplies the rhomboids? What movement are the rhomboids responsible for?
Dorsal scapular nerve
Retracts, rotates + 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?
What movements are levator scapulae responsible for?
Dorsal scapular nerve (+ C3 + C4)
Elevates + rotates the scapula
Which muscles make up the intrinsic shoulder muscle compartment?
Rotator cuff muscles (supraspinatus, infraspinatus, teres minor + subscapularis)
Teres major
Deltoid
Describe the attachments of deltoid.
Proximal: lateral 1/3 of the clavicle, acromion process + 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
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 of humerus
Innervated by suprascapular nerve
Infraspinatus : Infrascapular fossa to greater tubercle of humerus
Innervated by suprascapular nerve
Teres minor:
Upper 2/3 of the lateral margin of scapula to greater tubercle of humerus
Innervated by the axillary nerve
Subscapularis:
Subscapular fossa to the lesser tubercle of humerus
Innervated by the subscapular nerve
Which rotator cuff muscle is important for abducting the arm?
Supraspinatus: important in 1st 15 degree of abduction of the arm
Then the deltoid takes over.
Describe the attachments of teres major.
Which nerve innervates teres major?
Inferior angle of the scapula to the medial lip of the intertubercular sulcus of humerus
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 + glenoid labrum
Short head: coracoid process
Distal attachment: radial tuberosity + biceps aponeurosis
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?
Which nerve innervates the posterior compartment of the arm?
Triceps
Anconeus
Radial nerve
What are the attachments of the triceps?
Long head: infraglenoid tubercle of scapula
Medial + 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 4 joints make up the pectoral girdle?
Sternoclavicular
Acromioclavicular
Gleno-humeral
Scapulo-thoracic (physiological joint)
Which 2 ligaments make up the coracoclavicular ligament?
Conoid ligament
Trapezoid ligament
Which 3 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 does the rotator cuff do to the humeral head?
Holds humeral head within the glenoid cavity
Depresses the humeral head
What are the movements of the scapula-thoracic joint?
Elevation/ depression of scapula
Protraction/ retraction of scapula
Rotation of scapula
What is the shape of the axilla?
Pyramid
What does the axilla contain?
Nerves: the brachial plexus
Arteries: axillary artery + its branches
Veins: axillary vein + its branches
Lymphatic vessels + lymph nodes
What are the 4 walls of the axilla?
Apex: 1st rib, clavicle + superior border of scapular
Anterior wall: pectoralis major + pectoralis minor
Lateral wall: inter tubercular groove of humerus
Medial wall: upper thoracic wall + serratus anterior
Posterior: subscapularis, teres major + latissimus dorsi
Describe the divisions of the subclavian artery as it passes into the axilla and down the arm.
At passing 1st rib subclavian becomes axillary artery
Passes inferior border of teres major, Axillary artery becomes brachial artery
At elbow level brachial artery divides into radial + ulnar arteries
Which branch of the axillary artery goes around the humerus?
Circumflex humeral artery
Describe the superficial venous anatomy of the arm.
2 main superficial veins: cephalic (lateral) + basilic (medial)
Above the elbow basilic vein joins venae comitantes to form the axillary vein
Cephalic vein drains into the axillary vein more superiorly
Axillary vein becomes subclavian vein at level of 1st rib
Which small communicating 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
Subclavian lymph trunk
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 Terminal Branches
What are the five largest nerves of the brachial plexus?
Musculocutaneous Axillary Radial Median Ulnar
What is the function of the subclavius muscle?
Stabilises the clavicle
What is the function of Pectoralis minor?
Pulls coracoid anteriorly + inferiorly
Describe the attachments of trapezius
Nuchal line of skull
Spines of cervical + thoracic vertebrae down to T12
Anterior: Acromion + clavicle
What is the biggest artery branching off the brachial artery?
Profunda brachii
Which nerves pass through the upper arm but don’t supply anything till they reach the forearm?
Median nerve
Ulnar nerve
