Upper limb

• The pectoral girdle is associated with the lateral aspect of the lower portion of the neck
• Clavicle:

  Extends between the manubrium of the sternum and the acromion of the scapula.

  Slender 'S' shape

  Medial aspect is convex & quadrangular sternal end

  Lateral aspect is concave & flattened acromial end

  Inferior surface (lateral third) is rougher than the superior surface:

  • subclavian groove
  • conoid tubercle
  • trapezoid line- conoid & trapezoid form coracoclavicular ligament attachment
• What are the angles of the scapula?

  • Lateral (glenoid cavity)
  • Medial
  • Inferior
• What are the borders of the scapula?

  Superior border: coracoid, suprascapular notch

  Medial: thin and sharp

  Lateral: thicker for muscle attachment
• What are the 3 processes of the scapula?

  Acromion- articulates with the clavicle

  Coracoid- positioned inferior to the lateral end of the clavicle

  Spinous
• 2 surfaces of the scapula:

  Costal surface: consisting of the subscapular fossa

  Posterior surface: divided by the spine into the smaller supraspinous fossa and the larger infraspinous fossa
• Infraglenoid tubercle:

  Inferior to the glenoid cavity is where the long head of triceps brachii attaches
• Supraglenoid tubercle:

  Superior to the glenoid cavity is where the long head of biceps brachii attaches
• The proximal end of the humerus consists of:

  • a head
  • an anatomical neck
  • a surgical neck
  • a lesser tubercle (anterior)
  • a greater tubercle (lateral)
  • intertubercular sulcus separates the greater and lesser tubercles (tendon of long head of biceps brachii passes through this sulcus)
• The greater tubercle:

  • superior facet-attachment for supraspinatus
  • middle facet- attachment for infraspinatus
  • inferior facet- attachment for teres minor
• What are the superficial muscles of the shoulder?

  • trapezius
  • deltoid
• Trapezius

  • attaches the scapula & clavicle to the trunk
  • Origin: superior nuchal line, external occipital protuberance, medial margin of ligamentum nuchae, spinous process of C7-T12 and the related supraspinous ligaments
  • Insertion: superior edge of the crest of the spine of the scapula, acromion, posterior border of lateral third of clavicle
  • Innervation: motor= spinal part of accessory n., sensory = anterior rami of C3-C4
  • Function: elevates scapula, rotates scapula during abduction of the humerus above horizontal, middle fibres retract scapula, lower fibres depress scapula
• Deltoid:

  • Attaches the scapula and clavicle to the humerus
  • Origin: Inferior edge of the spine of the scapula, lateral margin of the acromion, anterior border of lateral third of clavicle
  • Insertion: deltoid tuberosity of humerus
  • Innervation: axillary nerve (C5, C6)
  • Function: Major abductor of the arm, clavicular fibres assist in flexing the arm; posterior fibres assist in extending the arm
• What are the deeper muscles of the shoulder?

  • levator scapulae
  • rhomboid minor
  • rhomboid major
• Levator scapulae:

  Origin: Transverse processes of C1 & C2 & posterior tubercles of transverse processes of C3 & C4

  Insertion: Posterior surface of medial border of scapula from superior angle to root of spine of scapula

  Innervation: Anterior rami of C3 & C4 and the dorsal scapular nerve

  Function: elevates the scapula
• Rhomboid minor:

  Origin: Lower end of ligamentum nuchae and spinous processes of C7 and T1

  Insertion: Posterior surface of medial border of scapula at root of spine of scapula

  Innervation: Dorsal scapular nerve (C4, C5)

  Function: Elevates & retracts scapula
• Rhomboid major:

  Origin: Spinous processes of T2-T5 and related supraspinous ligaments

  Insertion: Posterior surface of medial border of scapula from the root of the spine to the inferior angle

  Innervation: Dorsal scapular nerve (C4, C5)

  Function: Elevates & retracts scapula
• Posterior scapula region:

  Contains 4 muscles which pass between the scapula & proximal end of humerus: supraspinatus, infraspinatus, teres minor, teres major. And also includes the long head of the triceps brachii which passes between the scapula & the proximal end of the forearm.
• What are the SITS muscles?

  • supraspinatus
  • infraspinatus
  • teres minor
  • subscapularis
• Supraspinatus:

  Origin: Medial 2 thirds of the supraspinous fossa of the scapula & the deep fascia that covers the muscle

  Insertion: Most superior facet of the greater tubercle of the humerus

  Innervation: suprascapular nerve (C5, C6)

  Function: Rotator cuff muscle; initiation of abduction of arm to 15 degrees at glenohumeral joint
• Infraspinatus:

  Origin: Medial 2 thirds of the infraspinous fossa of the scapula & the deep fascia that covers the muscle

  Insertion: Middle facet on posterior surface of the greater tubercle of the humerus

  Innervation: Suprascapular n. (C5, C6)

  Function: Rotator cuff muscle, lateral rotation of arm at glenohumeral joint
• Teres minor:

  Origin: Upper 2 thirds of a flattened strip of bone on the posterior surface of the scapula, immediately adjacent to the lateral border of the scapula

  Insertion: Inferior facet on the posterior surface of the greater tubercle of the humerus

  Innervation: Axillary nerve (C5, C6)

  Function: Rotator cuff muscle, lateral rotation of arm at glenohumeral joint
• Teres major muscle:

  Origin: Elongate oval area on the posterior surface of the inferior angle of the scapula

  Insertion: Medial lip of the intertubercular sulcus on the anterior surface of the humerus

  Innervation: Inferior subscapular nerve (C5, C6, C7)

  Function: Medial rotation & extension of the arm at the glenohumeral joint
• Long head of triceps brachii:

  Origin: Infraglenoid tubercle on scapula

  Insertion: Common tendon of insertion with medial & lateral heads on the olecranon process of the ulna

  Innervation: radial nerve (C6, C7, C8)

  Function: Extension of the forearm at the elbow joint, accessory adductor & extensor of the arm at the glenohumeral joint
• What are the 2 major groups of back muscles?

  • Extrinsic (appendicular group) back muscles - includes superficial & intermediate muscles
  • Intrinsic (deep) back muscles
• Extrinsic (appendicular) muscles of the back:

  Innervated by the anterior rami of spinal nerves

  Function: produce & control movements

  Upper limb: superficial group

  Respiratory: intermediate group
• Intrinsic (deep) back muscles:

  Develop in the back

  Innervated by posterior rami of the spinal nerves

  Function: maintain posture & move vertebral column
• Back- extrinsic muscles

  Superficial muscles: Latissimus dorsi, trapezius

  Deeper: levator scapulae, rhomboid minor, rhomboid major

  Intermediate: Serratus posterior superior & serratus posterior inferior
• Latissimus dorsi:

  Origin: Spinous process of T7 to L5 & sacrum, iliac crest, ribs 10-12

  Insertion: Floor of intertubercular sulcus of humerus

  Innervation: Thoracodorsal nerve(C6-C8)

  Function: extends, adducts & medially rotates the arm
• Serratus posterior superior:

  Origin: Lower portion of ligamentum nuchae, spinous process of C7 to T3 & supraspinous ligaments

  Insertion: Upper borders of ribs 2-5 just lateral to their angles

  Innervation: Anterior rami of upper thoracic nerves (T2-T5)

  Function: elevates ribs 2 to 5
• Serratus posterior inferior:

  Origin: Spinous process of T11 to L3 and supraspinous ligaments

  Insertion: Lower borders of ribs 9-12 just lateral to their angles

  Innervation: anterior rami of lower thoracic nerves (T9-T12)

  Function: depresses ribs 9 to 12 - may prevent ribs from being elevated when the diaphragm contracts
• Function of the tendons of the rotator cuff muscles?

  Provides strong lateral stability

  Stabilizes head of humerus in glenoid cavity & prevents dislocation
• What are the 4 posterior scapular gateways?

  • Suprascapular foramen
  • Quadrangular space
  • Upper triangular space
  • Lower triangle space aka triangular interval
• Suprascapular foramen:

  • Route between base of neck & posterior scapular region
  • Boundaries: inf- suprascapular notch of scapula, sup- suprascapular ligament
  • Transmits: suprascapular nerve
  • Vessels usually follow the nerve but above the ligament
• Quadrangular space:

  • Route between the anterior region like the axilla & the posterior scapula region
  • Boundaries: Inferior margin of teres minor, surgical neck of humerus, superior margin of teres major, lateral margin of long head of triceps brachii
  • Transmits: axillary nerve, posterior circumflex humeral artery
• Upper triangular space:

  • Route between the anterior & posterior arm & axilla
  • Boundaries: medial margin of long head of triceps brachii, inferior margin of teres minor, superior margin of teres major
  • Transmits: circumflex scapular artery & vein
• Lower triangular space:

  • Route between axilla & posterior scapular region
  • Boundaries: lateral margin of long head of triceps, shaft of humerus, inferior margin of teres major
  • Transmits: radial nerve, profunda brachii artery & associated veins
• Arterial anastomosis around the shoulder:

  Medial border of scapula: subclavian artery gives off the thyrocervical trunk which gives off the transverse cervical artery which gives off deep branch of transverse cervical artery

  Superior border: Subclavian artery gives off the thyrocervical trunk which gives off the suprascapular artery

  Lateral border: Axillary artery gives off the subscapular artery which gives off the circumflex scapular artery

  Head & neck of humerus: axillary artery gives off anterior & posterior circumflex humeral artery
• Superficial:

  Masses of connective tissue visible to the unaided eye made of irregularly interwoven collagen

  Merges with the skin

  Contains adipose- between muscle & skin

  Contains subcutaneous nerves, vessels & lymph, striated muscles
• Superficial compartment- the breast

  Base: from rib 2-6 & runs transversely from the sternum to the midaxillary line

  Lies anterior to pectoral muscles on deep fascia: separated by retromammary space, allows for movement

  Consists of: skin, predominantly fat in non-lactating women, mammary glands, connective tissue