Outline 6: Shoulder Flashcards
Blood supply of shoulder
Branches of subclavian and axillary arteries
Shoulder muscles that are “direct”, trunk to humerus
- Pec major
2. Latissimus dorsi
Extrinsic shoulder muscles move (X) with respect to (Y)
X = shoulder girdle Y = axial skeleton
The anterior extrinsic shoulder muscles are:
- Pec minor
2. Subclavius
The posterior extrinsic shoulder muscles are:
- Trapezius
- Locator scapulae
- Rhomboids
Intrinsic shoulder muscles move (X) relative to (Y)
X = free limb Y = shoulder girdle
Intrinsic shoulder muscles include:
- Rotator cuff (SITS)
- Teres major
- Deltoid
Subclavius is an example of a (spurt/shunt) muscle
Shunt
Serratus anterior is which type of shoulder muscle?
Extrinsic
Shoulder abduction is initiated by:
Supraspinatus
Source of shoulder nerve innervation is (anterior/posterior) rami of spinal nerves (X) to (Y). This is formally termed (Z)
Anterior
X= C5 Y = T1 Z = Brachial plexus
How many shoulder joints? List them. Which isn’t REALLY a joint, and why?
4 shoulder joints:
Scapulothoracic, sternoclavicular, acromioclavicular, glenohumeral
Scapulothoracic not really joint: no articulating surface
Glenohumeral joint connects:
Humerus to scapula
Sternoclavicular joint connects:
Clavicle to sternum
Acromioclavicular joint connects:
Scapula to clavicle
Scapulothoracic joint connects:
Scapula to rib cage
Muscles involved in scapula elevation:
- Levator scapulae
2. Upper fibers of trapezius
Muscles involved in scapula depression:
- Lower fibers of trapezius
2. Pec minor
Muscles involved in retraction of scapula:
- Rhomboids
2. Middle fibers of trapezius
Muscles involved in protraction of scapula
- Pec minor
2. Serratus anterior
Muscles involved in upward/downward rotation of scapula
Upward: trapezius (upper and lower fibers), serratus anterior
Downward: pec minor, levator scapulae, rhomboids
The sternoclavicular joint has how many major ligaments? Name ‘em.
3 total
- Sternoclavicular ligaments (anterior and posterior)
- Costoclavicular ligament
- Interclavicular ligament
What is the fibrous capsule of the sternoclavicular joint attached to?
Clavicle, sternum, and articulating disk
Blood supply of sternoclavicular joint:
- Clavicular branch of thoracoacromial trunk
- Internal thoracic artery
- Inferior branch of thyrocervical trunk
Sternoclavicular joint is what type of joint?
Plane joint
Sternoclavicular joint has how many joint spaces?
2
Acromioclavicular joint has how many major ligaments? Name them.
2 ligaments
- Acromioclavicular
- Coracoclavicular
The acomioclavicular ligament function:
Reinforces scapula
Acromioclavicular joint blood supply
Acromial rete
The Acromial rete stems from:
Acromial and deltoid arteries
Acromioclavicular joint nerve innervation:
Suprascapular, axillary, pectoral nerves
Acromioclavicular joint is which kind of joint?
Plane joint
The glenohumeral joint is similar to which other joint?
Hip joint
Ligaments of glenohumeral joint:
- Coracohumeral
- Glenohumeral
- Transverse
Ligament that spans the intertubercular groove of the humerus:
Transverse ligament of glenohumeral joint
Coracohumeral ligament specifically attaches to:
Coracoid process and tubercle of humerus
95% of shoulder dislocations occur as result of movements in which direction(s)?
Anterior and inferior movements
To add superior reinforcement to the shoulder joint, the (X) ligament attaches to which two structures to form the (Y) arch?
X = Y = coracoacromial
Connects coracoid process and acromion process
Bursae in the glenohumeral joint is (above/under) acromion and (above/under) deltoids.
Under; under
Blood supply of glenohumeral joint:
- Suprascapular artery
2. Two circumflex humeral arteries
Glenohumeral joint nerve supply
Axillary and suprascapular nerves
Muscles involved in shoulder flexion:
Pec major, biceps (short head), deltoid (anterior), coracobrachialis
Muscles involved in shoulder extension:
Deltoids (posterior), triceps (long head), latissimus dorsi
Muscles involved in internal rotation of shoulder:
Latissimus dorsi, deltoids (anterior), subscapularis, pec major, teres major
Muscles involved in external rotation:
Infraspinatus, teres minor, deltoids (posterior)
Dynamic stability of shoulder (GH) joint is maintained primarily by which muscles?
Rotator cuff
Borders of the triangular space:
Teres minor (superior), teres major (inferior), long head triceps (lateral)
Content(s) of triangular space:
Circumflex scapular artery
Borders of quadrangular space:
Long head triceps (medial), teres minor (superior), teres major (inferior), and surgical neck humerus (lateral)
Content(s) of quadrangular space:
PCHA and axillary nerve
A lesion in suprascapular nerve at the suprascapular notch affects which muscle(s) and which movement(s)?
Muscles: supraspinatus and infraspinatis
Actions: can’t initiate abduction; compromised external rotation
Lesion in the long thoracic nerve at ribs affects which muscle(s) and action(s)?
Serratus anterior; winged scapula and compromised upward rotation of scapula
Lesion in axillary nerve by proximal humerus affects which muscle(s) and action(s)?
Teres minor and deltoids
Compromised external rotation, extension, abduction
