Conversation so far:
where does the head of the humerus fit into the scapula
The head of the humerus fits into a shallow socket on the scapula called the glenoid.
in what part of the body is the glenoid
The glenoid cavity or glenoid fossa of scapula is a part of the shoulder.

Question: is there any cartilage
Self-contained rewrite: is there any cartilage in the glenoid cavity