Glenohumeral Joint
The glenohumeral joint, also known as the shoulder joint, is a ball-and-socket joint that connects the head of the humerus to the glenoid fossa. The glenoid fossa is a shallow cavity located on the angle of the scapula. This joint provides ample mobility, allowing for internal and external rotation, as well as the ability to flex and extend up to 180 degrees. To facilitate smooth movement, synovial fluid is present to reduce friction between the bones.
Pectoralis Minor Muscle
The pectoralis minor muscle is a triangular muscle that originates from the third to fifth ribs. It is connected to the coracoid process and plays a role in respiration. Working in partnership with the serratus anterior muscle, the pec minor helps the scapula achieve various motions, such as downward rotation and abduction. The thoracoacromial artery provides the blood supply to this muscle, branching off into a larger artery in the upper chest.