Glenoid

Glenoid
File:Glenoid cavity.png The glenoid cavity of the scapula
Details
System	Skeletal
Artery	Suprascapular artery
Nerve	Suprascapular nerve
Identifiers
Latin	cavitas glenoidalis
TA98
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terminology

The glenoid (from the Greek "glenoeides" meaning "socket-like") is a part of the scapula (shoulder blade) that forms the socket of the glenohumeral joint, commonly known as the shoulder joint. This joint is a ball-and-socket type, where the head of the humerus (upper arm bone) fits into the glenoid cavity, allowing for a wide range of motion.

Anatomy

The glenoid cavity is a shallow, pyriform articular surface, which is located on the lateral angle of the scapula. It is directed laterally and forward, and articulates with the head of the humerus. The cavity is slightly concave and is covered with cartilage in a living person.

Glenoid Labrum

Surrounding the glenoid cavity is the glenoid labrum, a fibrocartilaginous rim that deepens the cavity and provides stability to the shoulder joint. The labrum serves as an attachment site for the long head of the biceps brachii tendon and the glenohumeral ligaments.

Blood Supply

The blood supply to the glenoid region is primarily provided by the suprascapular artery, which branches from the thyrocervical trunk of the subclavian artery.

Innervation

The glenoid and its associated structures are innervated by the suprascapular nerve, which arises from the upper trunk of the brachial plexus.

Function

The primary function of the glenoid is to serve as the socket for the shoulder joint, allowing for a wide range of motion including flexion, extension, abduction, adduction, and rotation. The shallow nature of the glenoid cavity allows for greater mobility but also requires additional structures, such as the labrum and surrounding muscles, to provide stability.

Clinical Significance

The glenoid can be involved in various shoulder pathologies, including:

• Glenoid Labrum Tears: Often seen in athletes, these tears can lead to shoulder instability and pain.
• Glenoid Fractures: These are less common but can occur due to trauma and may require surgical intervention.
• Arthritis: Degenerative changes in the glenoid can lead to osteoarthritis of the shoulder joint.

Also see

• Scapula
• Humerus
• Glenohumeral joint
• Rotator cuff
• Shoulder joint