Intrinsic Muscles of the Glenohumeral Joint Flashcards
What are the origins of Deltoid?
- crest of SPINE of SCAPULA
- lateral margin of ACROMION
- lateral 1/3 of CLAVICLE
What are the insertions of Deltoid?
Deltoid tuberosity of HUMERUS?
What are the movements Deltoid participates in?
- abducts arm
- flex arm
- extend arm
What is the innervation of Deltoid?
Axillary nerve (C5, C6)
What are the muscles of the Rotator Cuff?
- Supraspinatus
- Infraspiantus
- Teres Minor
- Subscapularis
What are the origins of SupraSpinatus?
Supraspinous fossa of the scapula
What are the insertions of Supraspinatus?
-most superior facet on the greater tubercle of the humerus
What does the supraspinatus muscle do?
- Initiates the abbduction of the arm to 15 degrees
- Stabilizes the glenohumeral joint
What is the nerve supply of supraspinatus?
Suprascapular Nerve (C5, C6)
What is the origin of Infraspinatus?
Infra spinatous fossa of the scapula
What is the insertion of Infraspinatus?
MIDDLE facet on the posterior surface of the greater tubercle of the humerus.
What is the nerve supply of infraspinatus?
Suprascapular nerve [C5, C6]
What are the main actions of the Infraspinatus Muscle?
Lateral Rotation of the arm
What are the origins of Teres MINOR?
Middle part of lateral border of scapula
What are the insertions of Teres MINOR?
Inferior facet on greater tubercle of the humerus
What is the nerve supply of Teres MINOR?
Axillary Nerve (C5, C6)
What is the main action of teres minor?
Lateral rotation of the arm
What is the origin of Teres MAJOR?
Inferior angle of Scapula
What is the insertion of Teres Major?
Medial Lip of intertubercular groove (bicipital groove) of humerus
What is the nerve supply of Teres Major?
Lower subscapular nerve (C6)
What is the action of Teres MAJOR?
Adducts medially
rotates humerus
What are the origins of subscapularis?
Subscapular fossa of scapula
What are the insertions of subscapularis?
Lesser tubercle of humerus
What is the nerve supply of subscapularis?
Upper (C5) and lower (C6) subscapular nerves
What is the action of subscapularis?
Medial rotator and adductor of humerus
stabilize gleno-humeral joint
What are the boundaries of the quadrangular space?
Superiorly = Teres Minor Inferiorly = Teres Major Medially = Long head of Triceps Brachii Laterally = Humerus
Which artery and nerve are located within the quadrangular space?
- Axillary Nerve (C5, C6)
- Posterior circumflex artery + vein
Which muscles is responsible for the initiation of abduction?
Supraspinatous
What is the origin of the long head of Biceps Brachii?
supraglenoid tubercle of scapula
What is the origin of the short head of Biceps Brachii?
coracoid process of scapula
What is the insertion of biceps brachii?
Radial tuberosity
What is the origin of the long head of triceps brachii?
infraglenoid tubercle of scapula
What is the insertion of Triceps Brachii?
Olecranon Process of Ulna
Contraction of which muscles produce protraction of the scapula?
- pectoralis Major
- Pectoralis Minor
- Serratus Anterior
Contraction of which muscles produce retraction of the scapula?
Rhomboid Major
Rhomboid minor
Latissimus dorsi
Trapezius
Contraction of which muscles cause elevation of the scapula?
Trapzius
Levator Scapulae
Rhomboid Major / minor
Contraction of which muscles cause depression of the scapula?
Pectoralis Major Pectoralis Minor Latissimus dorsi Trapezius Serratus Anterior
Lateral Rotation is caused by the contraction of which muscles?
Infraspinatus
Teres Minor
