Flashcards in Shoulder and Pectoral Girdle Deck (38):
What innervates the trapezius and deltoid?
trapezius is the accessory
deltoid is the axillary
Where is the clavicle palpable?
along its entire length
What are the different shapes of the clavicle?
medial 2/3rd it is circular and convex anteriorly
lateral 1/3rd is flattened and convex posteriorly
What are the markings on the clavicle?
on the lateral end it has a trapezoid line and a conoid tubercle where the Coracoclavicular ligaments come from
what are the unusual features of the clavicle?
no medullary cavity
first bone to ossify 5th-6th week
develops in membrane
most common fractured bone
What are the palpable regions of the scapula?
acromion, tip of coracoid, spine of scapula, medial border, inferior angle
What is the humerus like?
head is 1/3rd a sphere and faces upwards, medially and backwards, separated from greater and lesser tubercle by anatomical neck
What nerve is at the surgical neck?
axillary nerve and posterior circumflex artery
Where is the radial nerve?
posterior aspect has a groove
What is the weakest part of the humerus?
How do you treat a humeral fracture?
if no movement, then collar
if displaced then plates and screws
if lots of bony fragment then hemi arthroplasty
What are the three joints of the shoulder?
- sterno and acromio link two bones of pectoral girdle each other
What is the SternoClavicular Joint?
proximal end of clavicle and manubrium
synovial ball and joint
articular disc separating
allows movement in anteroposterior direction and vertical direction
anterior and posterior ligaments
What is the AcromioClavicular Joint?
between acromion and clavicle
movement in anteroposteiror and vertical direction and axial rotation
small acromioclavicular ligament
coracoclavicular ligament; from trapezoid and conoid ligament
What is the glenohumeral joint?
ball and socket joint
articular surface of the humeral head and glenoid cavity which is deepened by the glenoid labrum
capsule around is lax and lines by synovia lmembrane
long head of biceps brachii pierves through the capsule and lies within the joint and is also lined by synovial membrane
What provides stability to the gelnohumeral joint?
rotator cuff muscles
long head of biceps
What are the bursae of the Glenohumeral joint?
this is where synovial membrane can pierce through capsule
- subtendinous bursa of subscapularis between subscapularis and capsule
help to reduce friction of tendon and capsule
- Subacromial bursa, between supraspinatus and acromion
- subdeltoid bursa, between greater tubercle and deltoid
What are the ligaments of the Glenohumeral joint?
reinforced by superior, middle and inferior ligaments that go from joint capsule to the lesser tubercle
coracohumeral ligament from coarcoid to greater tubercle
transverse humeral, holds tendon of long head in place
What are the rotator cuff muscles?
What is the Supraspinatus?
originates; medial 2/3rd of supraspinous fossa, passes laterally under acromion and separated from coracoacromial ligament by subacromial bursa
inserts onto superior facet of greater tubercle
initiates first 15 degrees of abduction
SUPRASCAPULAR NERVE, C5/6
What is the infraspinatus?
origins at medial 2/3rd of indraspinous fossa
insets on middle facet of greater tubercle
laterally rotates the arm
suprascapular nerve, C5,C6
What is the Teres Minor?
origin on posterior surface of scapula adjacent to lateral border
inserts onto inferior facet of greater tubercle
lateral rotation of the arm
axillary nerve C5,C6
What is the subscapularis?
origins medial 2/3rd of subscapularis fossa
inserts onto lesser tubercle
medial rotation of th ehumerus
adducts the shoulder
subscapular nerve C5,C6
What are possible Rotator Cuff Disorders?
- supraspinous tendinitis, can impinge on the subacromial bursa and lead to painful arch of shoulder movement between 60-120
- supraspinous has poor blood supply so is likely to, on repetitive trauma undergo degenerative changes and calcium can deposit
What is the function of the Deltoid?
abducts arm to 90 degrees
What is the Trapezius?
origin- superior nuchal line, external occipital protuberance, C7-T12 spinous processes, ligamentum nuchae
insertion- spine of scapula, lateral third of clavicle, acromion
function- rotates the scapula enabling arm abduction beyond 90-180 aided by serratus anterior
What is the Serrattus Anterior?
origin- lateral surface of upper 8-9 ribs
inserts- costal surface of medial border of scapula
protracts and rotates scapula
keeps inferior angle and medial border close to thoracic wall
long thoracic nerve - the long thoracic nerve is passed down on external surface of the serratus anterior and is prone to damage, causing winging of scapula
What is the Biceps Brachii?
long head is attached to the supraglenoid tubercle and short head to the coracoid process
both form a central tendon and attach at the bicipital aponeurosis and the radial tuberosity
flexes the upper arm at the glenohumeral joint and forearm at elbow
how does the long head of tricepts add to joint stability>
origin of infraglenoid tubercle of scapula and attaches to olecranon, extends upper arm at GH joint, forearm at elbow joint
ONLY MUSCLE FOUND ON INFERIOR ASPECT OF SHOULDER JOINT
What is the Pectoralis Major?
originates - clavicular head comes from anterior surface of medial half of clavicle, sternocostal head from sternum, firs 7 costal cartilages and first 6 ribs
inserts onto lateral lip of intertubercular sulcus
flexion, adduction and medial rotation of GHJ
C5,6 and C6,7,8,T1
What is the latissimus dorsi?
originates from the lower 6 thoracic vertebrae, thoracocolumbar fascia, iliac crest and inferior 3-4 ribs
inserts onto the intertubercular sulcus
extension, medial rotation and adduction
What is the Teres Major?
posteiror surface on inferior angle of scapula to medial lip of intertubercular sulcus
medial rotation and extension of arm
subscapular nerve C5-6
What are the borders of the Axilla?
anterior border- two layers, pec major and minor
medial- serratus anterior and thoracic wall
lateral- intertubercular sulcus of the humerus
posterior-subscapularis, teres major and lat dorsi
base is deep fascia stretching from chest to arm
Where is the apex of the axilla?
between middle third of clavicle and outer edge of first rib
cervico axillary opening transmits subclavian artery and brachial plexus into axilla
axillary vein vein into neck
What are the contents of the axilla?
cord of brachial plexus
What does the axillary nerve innervate?
teres minor and deltoid
What does the axillary nerve do?
winds its way around the surgical neck posteriorly to enter the deltoid