Wednesday, October 26, 2011

Bones of the Shoulder

shoulder anterior view shoulder posterior view

What bones are at this joint?

So the bones at the actual shoulder joint are the scapula or shoulder blade, and the humerus or upper arm bone.

What type of joint is this?

Here we are talking about the glenohumeral joint, which is a ball and socket synovial joint where the head of the humerus fits into the glenoid fossa or cavity of the scapula.

The scapula is a very funky bone, it's not just a straight up blade like a spade. It has a few weird protuberances, like it has a spine on the back that ends in a knobby bit called the acromion process. There's also a knobby bit in the front called the coracoid process, and in front of that another knobby bit called the supraglenoid tubercle, and under that is the glenoid cavity where the humerus fits in. Which you can sort of see on my skeleton but you know, not really, because this is not a very advanced skeleton. But it does basically have the right number of vertebrae and ribs, which is an advance for me.

What body part moves this joint?

The meaty parts that move the shoulder joint are your chest, shoulder, shoulder blades, and back.

What body part is moved at this joint?

The meat that is moved at your shoulder is your upper arm.