2 Glenohumeral joint and proximal humerus Flashcards
What is the name of the cavity on the lateral surface of the scapula?
Glenoid cavity
What articulates with glenoid cavity?
Head of the humerus
What type of joint is the glenohumeral joint?
Synovial ball and socket joint
What is the cartilage around the glenoid cavity?
Glenoid labrum
What is a tubercle on a bone?
Round notdule which significes attachment site of muscle/limb
How many tubercles does the humerus have?
2 - greater (laterally) and lesser (medially)
What are the two necks of the humerus?
Anatomical (superior to tubercles) and surgical (inferior to tubercles)
Surgical is where it’s most likley to fracture
What is the function of the greater tubercle if the humerus?
An attachment for 3 rotator cuff muscles
Supraspinatus
Infraspinatus
Teres minor
What is the function of the lesser tubercle if the humerus?
An attachment for last rotator cuff muscle
Subscapularis
What seperates the two tubercles
Intertubercular groove
What is the function of the intertubercular groove
Attachment of tendons of
Pectoralis major
Teres major
Latissimus dorsi
What are bith surfaces of the glenohumeral joint covered in?
Hyaline cartilage
What is larger the head of the humerus or glenoid fossa?
The head of the humerus which means the joint has instability
What is the purpose of the ligaments in the glenohumeral joint?
To strengthen and ease movements
What are the four main ligaments in the glenohumeral joint?
Glenohumeral ligaments
Coracohumeral ligament
Transverse humeral ligament
Coracoacromial ligament
What makes up the glenohumeral ligaments?
3 bands - superior, middle, inferior
Run from glenoid fossa to anatomical neck of humerus
What is the function of the glenohumeral ligaments?
To strengthen and stabilise anterior aspect of joint capsule
Where does coracohumeral ligament attach to?
Base of coracoid process to greater tubercle of humerus
What is the function of the coracohumeral ligament?
Support superior part of joint capsule
Where is transverse humeral ligament found?
Between greater and lesser tubercle of humerus
What is the function of the transverse humeral ligament?
Holds long head of tendon of biceps brachii in the intertubercular groove
Where is the coracoacromial ligament between?
Acromion and coracoid process of the scapula
What is the function of the coracoacromial ligament?
To prevent superior displacement of the humeral head
What is the joint capsule made up of?
Fibrous sheath
What is the function of a joint capsule?
To enclose the structures of a joint
Where is the glenohumeral joint capsule?
From anatomical neck of humerus to border of glenoid fossa
What lines the inner surface of a joint capsule?
Synovial membrane which produces synovial fluid (reduces friction between surfaces)
In glenohumeral joint what is present to reduce friction?
Synovial bursae, two clinically important ones are
Subacromial bursa
Subscapular bursa
What is a bursa
Sac filled with synovial fluid - wich acts as a cushion between tendons and other joint structures
What is the clinical significance of subacromial bursa?
Subacromial bursitis - a type of rotator cuff injury
Dislocation
What are the movements of the glenohumeral joint?
Extension, flexion
Abduction, adduction
Medial, lateral rotation
What muscles produce flexion at glenohumeral joint?
Biceps brachii
Pectoralis major
Anterior deltoid
Corachobrachialis
What muscles produce extension at glenohumeral joint?
Posterior deltoid
Latissimus dorsi
Teres major
What muscles produce abduction at glenohumeral joint?
0-15 Supraspinatus
15-90 Middle deltoid (help from supraspinatus)
Past 90 scapula rotation needs to occur
What muscles produce scapula roation past 90 for abduction at glenohumeral joint?
Trapezius
Serratus anterior
What muscles produce adduction at glenohumeral joint?
Pectoralis major
Lattisimus dorsi
Teres major
What muscles produce medial rotation at glenohumeral joint?
Subscapularis
Pectoralis major
Latissimus dorsi
Teres major
Anterior deltoid
What muscles produce lateral roation at glenohumeral joint?
Infraspinatous
Teres minor
