Scapular and Deltoid Regions Flashcards
What are the components of the axial skeleton vs. the appendicular skeleton?
Axial includes cranium, vertebral column, ribs & sternum
Appendicular includes clavicles, scapulae, pelvis & limbs
Which bones make up the pectoral girdle?
Scapula and clavicle
NOTE: Humerus is NOT a part of the pectoral girdle!!
5 Ligaments in the shoulder region
Coracoclavicular (trapezoid and conoid) Coracoacromial Superior glenohumeral Middle glenohumeral Inferior glenohumeral
Different motions of the scapula
Elevation/depression
Protraction/retraction
Upward/Downward rotation
Muscles that attach the scapula to the humerus and move the humerus at the shoulder joint and contribute to the stabalization of this joint are called what and include what muscles? What are they innervated by?
Called scapulohumeral muscles: Deltoid, teres major, serratus anterior and the rotator cuff muscles (subscapularis, supraspinatus, infraspinatus, teres minor)
Deltoid Proximal and Distal attachments
Proximal: lateral 3rd of clavicle, acromion and spine of scapula
Distal: Deltoid tuberosity of humerus
Actions of deltoid
flexes, medially rotates, abducts, extends and laterally rotates humerus
Blood supply and innervation of deltoid
Blood supply: deltoid branch of thoracoacromial arterial trunk
Innervation: axillary nerve (C5, C6)
Teres major proximal and distal attachment
Proximal: posterior surface of inferior angle of scapula
Distal: Medial lip of intertubercular groove of humerus
Teres major actions
adducts and medially rotates humerus
Blood supply and innervation of teres major
circumflex scapular artery
Lower subscapular nerve (C5, C6)
Serratus anterior proximal and distal attachments
Proximal: external surfaces of lateral parts of ribs 1-9
Distal: anterior surface of medial border of scapula
Action of serratus anterior
protracts scapula and hods it against thoracic wall; rotates scapula
Blood supply and innervation for serratus anterior
lateral thoracic artery
Long thoracic nerve (C5, C6, C7)
“raise your arms to heaven”
Which rotator cuff muscles attach to the greater tubercle of humerus? Which ones attach to lesser tubercle?
Supraspinatus, infraspinatus, and teres minor attach to greater tubercle
Subscapularis attaches to lesser tubercle
Supraspinatus proximal and distal attachments
Proximal: supraspinous fossa of scapula
Distal: superior facet of greater tubercle of humerus
Actions of supraspinatus
Works with deltoid in abduction of humerus, acts with other rotator cuff muscles in stabilizing shoulder joint
Blood supply and innervation to supraspinatus
suprascapular nerve (C4,5,6)
What specific parts are involved in shoulder impingement syndrome?
Supraspinatus tendon (tendonitis) Can also involve subacromial (bursitis)
What is the most commonly injured rotator cuff muscle? What is the method by which it gets injured?
Supraspinatus
> or equal to90 degree angle of humerus creates a compression point for the tendon of supraspinatus and it can also tear (common in elderly)
What are activities that can cause rotator cuff (esp supraspinatus) injuries?
Tennis, swimming, pitching stacking boxes or stocking shelves painting construction work bone spurs, anatomical variation of the acromion (i.e., odd-shaped acromion that limits the space within roof of glenoid fossa)
Subscapularis proximal and distal attachments
proximal: subscapular fossa (anterior surface of scapula)
Distal: lesser tubercle of humerus
Actions of subscapularis
medially rotates and adducts humerus
helps hold humeral head in space
Blood supply and innervation to subscapularis
subscapular artery
upper & lower subscapular nerves
Dorsal scapular nerve recieves contributions from what two nerve roots? Which one is its PRIMARY source?
C4 & C5 but C5 is its primary source!
C4 nerve root contributes to what 3 nerves?
Dorsal scapular n
Suprascapular n
n to subclavius
What are some nerves that the C5 nerve root contributes to?
Long thoracic, lateral pectoral, suprascapular, musculocutaneous, nerve to subclavius
- What is the largest and strongest Rotator cuff muscle?
- How common are isolated tears of this muscle and how common are injuries to this muscle?
- Injuring this muscle can lead to what other problems?
- Subscapularis
- Isolated tears are rare but fairly common sports injury in pitchers (powerful throwing motion), rotator cuff tendonitis
- Subscapularis injuries can lead to bicipital tendon instability and biceps tendonitis
Function of the transverse ligament of humerus
holds long tendon of biceps brachii in the intertubercular groove
Infraspinatus proximal and distal attachments
Proximal: infraspinous fossa of scapula
Distal:middle facet of greater tubercle of humerus
Action of infraspinatus
laterally rotates humerus, helps hold humeral head in place
BS and innervation to infraspinatus
suprascapular artery suprascapular nerve (c5, C6)
Teres minor proximal and distal attachments
Proximal: Middle part of lateral border of scapula
Distal: inferior facet of greater tubercle of humerus
Teres minor action
laterally rotates humerus, helps hold humeral head in place
BS and innervation to teres minor
circumflex scapular artery axillary nerve (C5, C6)
what is the difference between the right and left subclavian arteries?
Right originates at brachiocephalic trunk
Left originates at aortic arch
subclavian artery arises posterior to sternoclavicular joint and has 3 divisions in relation to scale muscle (medial, posterior, lateral)
Thyrocervical trunk arises from what major artery and branches into what arteries
subclavian gives off thyrocervical trunk branch which then has 3 major branches:
- Suprascapular artery
- Transverse cervical artery (cervicodorsal trunk) which branches into (superficial and deep branch)
- Ascending cervical (not that important)
- inferior thyroid a
**2: superficial branch also called superficial cervical a and deep branch also called dorsal scapular a
Branches of the medial part of subclavian artery
internal thoracic artery (mammary a)
vertebral artery
thyrocervical trunk
Branches of posterior part of subclavian artery
Costocervical arterial trunk:
- supreme intercostal artery
- deep cervical artery
Branches of lateral part of subclavian artery
No branches but dorsal scapular can arise independently from lateral part
Lateral border of 1st rib is where subclavian a becomes axillary a
Arteries from which major arteries conribute to anastomoses around the scapula, allowing collateral circulation to upper limb?
Subcalvian a and axillary a
What are the anastomosing arterial branches?
- Suprascapular artery (from subclavian a)
- Dorsal scapular a (from deep branch of transverse cervical a from subclavian a)
- Posterior intercostal arteries (from aorta)
- Circumflex scapular a (division of subscapular a from axillary a)
- Thoracodorsal a (division of subscapular a from axillary a)
If axillary artery is injured or occluded superior to subscapular artery, can blood still get to the rest of the arm, forearm and hand? If so, how?
Yes–via scapular anastomoses:
transverse cervical–>dorsal scapular–>circumflex scapular a
Dorsal scapular artery can arise from what two different arteries?
can come directly off of subclavian OR from the transverse cervical artery (in this case, its called deep branch of transverse cervical artery and occurs 30% this way)
Artery that runs along vertebral border of scapula is called what artery?
Dorsal scapular artery
Borders and vessels of Quadrangular space
Borders: triceps (lateral and long head), teres minor and major
Vessels: Axillary nerve, posterior circumflex humeral artery
Borders and vessels of triangular space
Borders: Teres minor, teres major, triceps LONG head
Vessels: circumflex scapular artery
Borders and vessels of triangular interval
Borders: Teres MAJOR, long and lateral heads of triceps
Vessels: deep brachial artery and radial nerve
