Upper - Pec Girdle and Shoulder Flashcards
what is the pectoral girdle composed of
framework of the shoulder made up of the clavicle and scapula (excluding the proximal end of the humerus)
what is the role of the pectoral girdle
connects upper limbs to axial skeleton and provide structural support to the shoulder region
also provide connection for muscles of the shoulder and arm movement
what joints are commented by the clavicle in terms of lateral and medial
sternoclavicular (medial) and acromioclavicular (lateral)
describe the shape of the clavicle (ie medial vs lateral)
s shaped contour
medial is quadrangular where’s lateral end of clavicle is flat
describe the articulation of the clavicle to the acromion process of the scapula
acromial end of clavicle has small oval facet which articulate with the medial surface of the acromion
describe the articulation of the clavicle to the sternum
large facet which articulates with the manubrium of the sternum and the first costal cartilage
describe the inferior aspect of the clavicle and why it is so
inferior surface of the lateral third of the clavicle has a distinct tuberosity (conoid tubercle) and lateral roughening (trapezoid line)
which surface of the clavicle is smoother
the superior surface of the clavicle is smoother as the inferior side is roughened by muscular attachments
which ribs do the scapula lie between
second and seventh rib
describe the overall surface structure of the scapula
three angles and three borders two surfaces (costal and posterior) Three processes (acromion, spine and caracoid)
what does the lateral angle of the scapula form and what does it articulate with
forms the glenoid cavity which articulates with the head of the humerus to form the glenohumeral joint (shoulder)
what anatomically is directly inferior to the glenoid cavity in the lateral view
triangular roughening of the infraglenoid tubercle which is the site of attachment for the long head of the triceps brachii
what anatomically is directly superior to the glenoid cavity in the lateral view
supraglenoid tubercle - site of attachment for biceps brachii
what is produced above and below the spine of the scapula
supraspinous fossa and infraspinous fossa
describe the structure, orientation and bone articulation of the acromion process
anertolateral projection (at back side of scapula - lateral end of spine) arches over the glenohumoral joint and articles with the clavicle
describe the structure and presentation of the costal surface of the scapula
anterior view - concave sub scapular fossa
what is the difference in structure of the lateral to the medial side of the scapula
lateral is thick and strong for muscle attachment and the medial side is thinner and sharper
the superior border of the scapula is marked on its lateral end by what
the caracoid process (anterolateral part)
supra scapular notch (medial to the root of the caracoid process)
what causes ACJ separation
tearing o the ligaments that hold the scapula and the clavicle together
what structures are present on the proximal end of the humerus
head
anatomical neck
surgical neck
greater and lesser tubercle
describe the position of the greater tubercle of the humerus and what its used for
lateral position seen in the anterior view providing attachment for supra/infra spinatous and teres minor
describe the position of the lesser tubercle of the humerus and what its used for
more anterior aspect of proximal humerus medial to greater tubercle
it is smooth due to the attachment of the subscapularis
the lateral, medial and floor of the intertuberculuar sulcus of the humerus has roughenings due to which muscular attachment
lateral lip of inter tubercular sulcus = Pec Major
medial lip = teres major
floor = lat dorsi
on the lateral side of the humerus is a v shape - what is that a sign for
deltoid tuberosity for the deltoid
what structures pass immediately posterior to the surgical neck of the humerus
axillary nerve, posterior circumflex artery
which directions can the scapula move
elevation / depression
protraction / retraction
what are the two superficial dorsal muscles
trapezius and the lat dorsi
which three muscles all attach to the medial border of the scapula spine
lector scapula
rhomboid minor and major
which three muscles make up the ventral aspect of the pectoral girdle
pec maj/min
serrates anterior
what are the two heads of the Pec Major
clavicular head
sternocostal head
name all the scapulohumerus muscles (help stabilise the shoulder)
deltoid subscaularis supraspinatus infraspinatus teres minor/major
what is the difference in role of the supra/infraspinatus
supra initiates abduction of the arm
infra laterally rotates as goes from posterior to posterior
describe the structure of the glenoumoral joint
synovial ball and socket articulation between the ganoid cavity of the scapula and the humerus
incongruent to allow more movement but less stabilisation
due to the shoulder joint being incongruent what provides this joint with stability
muscles of the rotator cuff (subscap, infra/supra, minor)
long head of the biceps/triceps brachii and extrascapular ligaments
dorado-acromial ligament and glenoid labrum (fibrous-cartilogenous surrounding the joint)
what covers the surfaces of the bones in the glenohumoral joint
hyaline cartilage
what structures reduce friction between tendons and adjacent joint capsules and bones in the shoulder
synovial bursae such as the subtendinous bursa of the subscapularis lies between subscap and fibrous membrane
which muscle of the shoulder is prone to impingement
supraspinatus tendon as it passes under the coracoacromial arch which leads to tears and inflammation
