The Shoulder Region Flashcards
Axilla borders
- pec. Minor and major form anterior axillary wall
- subscapularis,Lats, teres major form posterior axillary wall
- lateral thoracic wall and serratus anterior form the medial wall
- humerus of the arm forms lateral wall
- axillary fascia and skin from the lateral thoracic wall and the upper arm make up the floor
- the roof
What makes up the apex
Formed by the cervicoaxillary canal.
Narrow space between the clavicle and the first rib
Contents of the axillary
- axilla artery and its branches
- axillary vein and its tributaries
- axillary lymph node and vessels
- cords and terminal nerves of brachial plexus
What is the glenohumeral joint
- ball and socket synovial joint
- between the shallow glenioid cavity and the humerus
- composed of fibrous capsule, ligaments of the joint, synovial membrane, and 3 large bursae
Glenoid labrum
Rim of fibrous cartilage attached to the Glenoid cavity that deepens the articular surface
Glenohumeral dislocation of the humerus cause and damage
- rotator cuff muscles stabilize joint superiorly
- coracohumeral,capsular ligament and coracoacromial arch offer limited inferior support–90% dislocations inferior
- can damage the axillary nerve
Glenohumeral ligament
- superior, middle, lateral
- attaches humerus head to Glenoid cavity
Coracohumeral ligament
- Superior to glenohumeral ligament
- Between coracoid process of scapula to the lesser tuberosity of the humerus
Coracromial ligament
- btwn coracoid process and acromion process
- prevents superior dislocation of the humerus
Subtendinous bursa of the subscapularis
- Anterior of the GH joint.
- btwn tendon of the subscapularis and neck of the scapula.
- communicates with synovial cavity
Subacromial bursa
- superior to GH joint
- Under the coracoacromial ligament and above supraspinatus tendon and GH joint capsule.
Subdeltoid bursa
- lateral to GH joint
- Deep to deltoid muscle and above the subscapularis tendon.
- communicates with subacromional bursa
deltoid
Origin
Clavicular: lateral 1/3 of clavicle.
Acromial: acromion
Spinal: scapular spine.
Deltoid
Insertion
Deltoid tuberosity on the Humerus
Deltoid innervation
Axillary nerve (C5-6)
Deltoid action
Clavicular: fled ion, internal rotation, adduction
Acromial: abduction.
Spinal: extension, external rotation, adduction.
Supraspinatus origin
Supraspinous fossa of the scapula
Supraspinatus insertion
The anterior facet of the Greater tuberosity of the humerus
Supraspinatus innervation
Suprascapular nerve C5-6
Supraspinatus action
Abduction (first 15 degrees, deltoid then takes over)
Infraspinatus origin
Infraspinous fossa of the scapula
The axilla
-passageway for neurovascular structures btwn trunk and upper limb
Infraspinatus insertion
Medial facet of the greater tuberosity of the humerus
Infraspinatus innervation
Suprascapular nerve(C4-6)
Infraspinatus action
External rotation
Teres minor origin
Scapula lateral border
Teres minor insertion
Inferior facet of the Greater tuberosity of the humerus
Teres minor innervation
Axillary nerve C5-6
Teres minor action
External rotation, weak adduction
Subscapularis origin
Subscapular fossa of the scapula
Subscapularis insertion
Lesser tuberosity of the humerus
Subscapularis Innervation
Subscapular nerve (C5-6)
Subscapularis action
Internal rotation
What muscles make up the rotator cuff?
Supra/infra spinatus, teres minor, and subscapularis
Pectoralis major origin
Clavicular: clavicle medial half
Sternocostal: sternum and costal cartilages 1-6
Abdominal part: rectus sheath anterior layer
Pectoralis major insertion
Crest of the Greater tubercle on the humerus
Pectoralis major innervation
Medial and lateral pectoral nerve (C5-T1)
Pectoralis major action
Entire muscle: adduction and internal rotation.
Clavicular and Sternocostal: flexion and respiration when shoulder is fixed
Teres major origin
Inferior angle of the scapula
Teres major insertion
Crest of the lesser tubercle of the humerus
Teres major innervation
Lower subscapular nerve (C5-7)
Teres major action
Internal rotation, adduction, extension
Lats origin
Vertebral: T7-12 spinous processes and Thoracolumbar fascia
Scapular: inferior angle
Costal: 9-12 ribs
Iliac; posterior 3rd
Lats insertion
Floor of the intertubercular groove of the humerus
Lats innervation
Thoracodorsal C6-8
Lats action
Internal rotation, adduction, extension, respiration
Coracobrachialis origin
Coracoid process of scapula
Coracobrachialis insertion
Humerus in line with the crest of the lesser tubercle
Coracobrachialis innervation
Musculocutaneous nn C5-7
Coracobrachialis action
Flexion, adduction, internal rotation.
Scapular notch
Limited superiorily by superior transverse ligament.
Deep to supraspinatus.
Suprascapular nerve passes below the ligament and suprascapular artery passes above it.
Quadrangular space boundaries and contents
Long head of tricep, the humerus, teres major and minor.
Contents: posterior circumflex humeral artery and axillary nerves
Triangle space boundaries and contents
Long head of the triceps and the teres major and minor muscles.
Contents: circumflex scapular artery
Triceps hiatus
Between the long and lateral heads of the triceps and inferior to teres major.
Contents: radial nerve and deep brachial artery.
Ligaments of the shoulder (GH joint)
coracohumeral, Glenohumeral, and coracoacromial ligaments.
3 large bursae and a fibrous capsule
