Pectoral region & Shoulder Flashcards
Sternoclavicular joint(articular components and joint type)
Sternal ends of the clavicle and manubrium of sternum
Joint type: Modifies saddle type synovial joint
Sternoclavicular joint (associated structures and movement)
Fibrocartilage disc
Movement:elevation/depression
protraction/retraction
Acromioclavicular joint (articular components and joint type)
Acromial end of the clavicle and acromion process of scapula
Joint type: Plane type synovial joint
Acromioclavicular joint (associated structures and movement)
Fibrocartilage disc
Movement: gliding between clavicle
Glenohumeral joint (articular components and joint type)
Humeral head and glenoid fossa
Joint type: ball and socket synovial
Glenohumeral joint(movement and features)
Felxion/extension
abduction/adduction
internal and external rotation
Glenoid fossa is 1/3 the size of the humeral head
Both non-contractile and contractile structures enhance stability
what are the non-contractile structures of the glenohumeral joint?
- coracoacromial ligament
- glenohumeral ligaments
- glenoid labrum
what are the contractile structures of the glenohumeral joint?
muscles of the rotator cuff
What is the coracoacromial arch formed by?
smooth inferior aspect of the acromion and the coracoid processof the scapula with the corcoacromial ligament
What is the function of the coracoacromial arch/ligament?
To prevent superior humeral displacement from the glenoid cavity
Glenoid labrum
Fibrocartilaginous ring
attaches to the margins of the glenoid fossa
deepens the cavity
scapulothoracic joint(definition)
The physiological joint between the scapula and the thoracic wall
what movements happen at the scapulothoracic joint?
Elevation/depression
rotation, protraction/retraction
What happens in shoulder abduction that allows it to work properly?
During full abduction of the arm we have to laterally rotate our humerus to move the greater tuberosity out of the way
scapulohumeral rhythum
The glenohumeral joint doesn’t account for all the movement of the humerus.
So from 0-30 degrees it is solely the glenohumeral joint
from 30-180 the scapula moves to givei ti more motion at a 2:1 Glenohumeral/scapulothoracic movement
Trapezius muscle(attachments)
Superior nuchal line, external occipital protuberance, spinous process of C7-T12
-scapula spine, acromion, lateral 1/3 clavicle
Trapezius muscle(action)
Upper: elevates and upwardly rotates scapula
middle: adducts scapula
lower: depresses and upwardly rotates scapula
Trapezius muscle(innervation)
CN XI, C3, C4
latissimus dorsi muscle(attachments)
spinous process T7-T12, iliac crest, ribs 9-12
latissimus dorsi muscle (action)
Shoulder extension, adduction and internal rotation
latissimus dorsi(innervation)
Thoracodorsal nerve
Levator scapulae muscle(attachments)
transverse process of C1-C4
superior border of scapula
levator scapulae muscle(action)
elevates and downwardly rotates scapula
levator scapulae (innervation)
dorsal scapular nerve(C5)
rhomboid minor (attachments)
Spinous process C7-T1
medial scapular border at the level of root of the scapular spine
Rhomboid major(attachments)
spinous process T2-T5
medial scapular border from the level of spine to inferior angle
Rhomboid major and minor (action)
adducts/retracts and downwardly rotates scapula
Rhomboid major and minor (innervation)
dorsal scapular nerve
Pectoralis major(attachment)
CLavucular head: medial half of the clavicle
sternocostal head: anterior sternum, upper six costal cartilages
intertubercular groove of the humerus
Pectoralis major (action)
adducts and medially rotates humerus
Pectoralis major(innervation)
Lateral and medial pectoral nerves
Pectoralis minor(attachment,action and innervation)
Ribs 3-5
corocoid process of the scapula
Action: stabilizes scapula
innervation: medial pectoral nerve
Serratus anterior(attachment)
external surface of lateral parts of ribs 1-8
anterior surface of medial border of the scapula
Serratus anterior (action)
protracts & upwardly rotates the scapula, holds scapula against thoracic wall
serratus anterior( innervation)
Long thoracic nerve
Subclavius(attachment)
junction of first rib and costal cartilage
inferior surface of medal third of clavicle
subclavius(action)
anchors and depresses clavicle
subclavius(innervation)
nerve to subclavius
coracobrachialis(attachment)
tip of coracoid process
medial, middle 1/3 of humerus
coracobrachialis (action and innervation)
flex and adducts shoulder
-musculocutaneous nerve
Deltoid muscle (attachment)
Scapula spine, acromion, lateral 1/3 clavicle
deltoid tuberosity of humerous
deltoid muscle ( action)
Anterior: shoulder flexion
middle: should abduction
posterior: shoulder extension
deltoid muscle (innervation)
axillary nerve
teres major muscle(attachment)
inferior lateral aspect of posterior surface of scapula
medial lip of intertubercular groove of humerus
teres major muscle(action)
shoulder medial/internal rotation
teres major muscle(innervation)
lower subscapular nerve
List the rotator cuff muscles.
Supraspinatus
infraspinatus
teres minor
subscapularis
Supraspinatus muscle attachments
Supraspinous fossa
greater tubercle
infraspinatus muscle attachments
infraspinous fossa
greater tubercle
Teres minor muscle attachments
middle part of the lateral border of scapula
greater tubercle
subscapularis muscle attachments
subscapular fossa
lesser tubercle
Suprapinatus (action and innervation)
Shoulder abduction
suprascapular nerve
infraspinatus (action and innervation)
shoulder lateral/ external rotation
Teres minor (action and innervation)
Shoulder lateral/external rotation
axillary nerve
Subscapularis (action and innervation)
shoulder medial/internal rotation
upper subscapular nerve and lower subscapular nerve
what are the boundaries of the quadrangular space
Superior: Teres minor
inferior: teres major
medial: long head of triceps brachii
lateral: surgical neck of humerus
What structures go through the quadrangular space?
Axillary nerve and posterior humeral circumflex
