The Shoulder Region Flashcards
What does the pectoral girdle consist of?
clavicle and scapulae
What is the purpose of the pectoral girdle?
-holds arm onto axial skeleton -helps position the shoulder socket to get arm into different positions -gives more mobility
Describe the scapular bone
large, triangular shaped flat bone
Why does the scapular have so many processes?
large amount of muscle attachment to orientate it and move the upper limb
What are the angles of the scapula?
superior, inferior and lateral (acromial)
What is the most superior piece of the shoulder?
acromion
what are the processes of the scapula?
spine, acromion and coracoid process
what are the spaces of the scapular?
subscapular fossa, infraspinous fossa and supraspinous fossa and the glenoid cavity
Where do the infraspinous and supraspinous fossae lay on the scapula?
above and below the spine
what does the acromial end of the clavicle attach to? How is it shaped?
scapula flat
what does the sternal end of the clavicle attach to? how is it shaped?
-sternum -rounded
What purpose does the curvatures of the clavicles have?
help to bear weight
what are the two joints of the pectoral girdle?
scapulothoracic and glenohumeral joint
what is the scapulothoracic joint made up of?
attachment of the scapular and clavicle to the axial skeleton. Formed by the clavicle pressing onto the axial skeleton
What is the sternoclavicular joint classified as?
-synovial -multiaxial -plane/gliding joint
What is the sternoclavicular joint made up of?
clavicle articulation with the manubrium
What are the supportive features of the joint made up of?
-articular disc for shock absorption -costoclavicular ligament: joins first rib to clavicle -sternoclavicular ligament: surrounds the joint
What movements can the sternoclavicular joint do?
-elevation -depression -protraction -retraction - bit of rotation when rotating the shoulder
What is the acromioclavicular joint classified as?
- synovial -multiaxial -plane/gliding
What is the acromioclavicular joint made up of?
lateral end of clavicle to acromion of the scapular
What supportive structures does the acromioclavicular joint made up of?
-articular disc for shock absorption -acromioclavicular ligaments: from acromion to clavicle directly around the joint -coracoclavicular ligament: from coracoid to clavicle
What are the movements of the scapula?
-elevation -depression -protraction -retraction -lateral (upward) rotation -medial (downward) rotation
What muscles cause depression?
latissimus dorsi, pectoralis major and pectoralis minor
What muscles cause elevation?
trapezius, levator scapulae and serratus anterior
what are the major muscles that move the scapular? What nerve supplies them?
trapezius, rhomboids and serratus. Supplied from branches of the brachial plexus
What are the attachment points of the trapezius?
Origin: Occiptial bone of the skull and the spinous processes of the cervical and thoracic vertebrae. Insertion: clavicle and scapula spine
What actions does the trapezius perform?
-elevation -retraction -lateral rotation
what actions does the… 1) middle trapezius 2) upper trapezius 3)lower trapezius
1) elevation 2) elevation and lateral rotation 3) depression and lateral rotation
What are the attachments of the rhomboid major and minor?
origin: SPs of the thoracic vertebrae insertion: medial boarder of scapulae
what are the actions of the rhomboid major and minor?
retract and laterally rotate the scapular
what angle are the fibers of the rhomboid major and minor?
oblique to rotate
what are the attachments of serratus anterior?
origin: ribs laterally insertion: anterior scapular margin
What are the actions of serratus anterior?
protract and laterally rotate the scapular
What is the attachments of levator scapulae?
origin: TPs of cervical vertebrae insertion: superior boarder and angle of the scapular
Classify the glenohumeral joint
- synovial -multiaxial -ball and socket
What makes up the glenohumeral joint?
head of humerus and glenoid cavity
Why is the joint capsule of the glenohumeral joint looser than others?
to allow more ROM
What are the movements of the glenohumeral joint? What plane do they occur on?
sagittal plane: flexion and extension frontal plane: adduction and abduction transverse plane: lateral and medial rotation circumduction
What makes the shoulder joint relatively unstable?
large ROM
What projections on the proximal humerus are for muscle attachment?
head, greater and lesser tubercles
What ligaments are associated with the glenohumeral joint?
coracoacromial and corahumeral (extrinsic)
Describe the coroacromial ligament
goes from coracoid to acromion. Reinforces superior aspect of the glenohumeral joint
describe the corahumeral ligament
Goes from coracoid to greater tubercle. Sits outside the joint capsule and runs superiorly to help suspend the head of the humerus
What are the rotator cuff muscles commonly known as?
rotator cuff muscles
What muscles are listed as rotator cuff muscles?
- teres minor - subscapularis - infraspinatus - supraspinatus
describe the characteristics and purpose of rotator cuff muscles
small muscles tightly situated around the glenohumeral joint to support it and hold the head of the humerus inside the capsule. Functions similarly to ligaments but are muscles.
What muscles go from the trunk to the humerus?
pectoralis major and latissimus dorsi
What muscles go from the girdle to the humerus?
deltoid, teres major and coracobrachialis
What rotator cuff muscle sits anterior to the joint?
subscapularis
what muscles sit superficially and posterior to the joint?
teres minor, supraspinatus, infraspinatus
What are the rotator cuff muscles innervated by?
brachial plexus
what are the attachments of pectoralis major?
sternum, ribs and clavicle to greater tubercle of the humerus
What are the actions of pectoralis major?
flexion, adduction and medial rotation
What direction do the fibers of pectoralis major go?
oblique, horizontal for rotation
What does the pectoralis major predominantly act upon?
arm but indirectly acts upon the shoulder
What is pectoralis major innervated by?
brachial plexus
What are the attachments of latissimus dorsi?
thoracic and lumbar vertebrae to intertubular groove of the humerus
What are the actions of latissimus dorsi?
extension, adduction and medial rotation - primarily extensor
What are the attachment points of the deltoid?
scapula spine and clavicle to the deltoid tuberosity of the humerus
what does the anterior deltoid cause?
flexion and medial rotation
what doe the middle deltoid cause?
abduction
what does the posterior deltoid cause?
lateral rotation and extension
what are the attachments of teres major?
inferior scapula to humerus
what does teres major cause?
extension, abduction and medial rotation
what are the attachments of coracobrachialis?
scapula to shaft of humerus
What are the actions of coracobrachialis?
flexion and abduction
What are the innervations for 1) deltoid 2) teres major 3) coracobrachialis
1) brachial plexus 2) brachial plexus 3) musculocutaneous nerve
How does the coracobrachialis differ to the deltoid and teres major?
it is a small, assisting muscle
What is the name of the main artery supplying the upper limb and why does it travel where it does?
- axillary - travels under armpit as is the safest passage
Label the following:
- superior, inferior and lateral angles
- spine, acromion and coracoid process
- subscapular, infraspinatus and supraspinatus fossa
- glenoid cavity
Label the following:
- trapezius
- rhomboid major and minor
- teres major and minor
- deltoid
- infraspinatus
- serratus anterior
- levator scapulae
Label the rotator cuff muscles
