When keying in on tennis elbow anatomy its most important to understand elbow muscles and the extensor tendons that attach to those muscles.
Knowledge is power and understanding the anatomy and details that going into making a healthy (or not so healthy) elbow will go a long way to helping you treat your tennis elbow.
If you are going to see a doctor or orthapedist for your tennis elbow please feel free to print out this page and take it with you. Hopefully they can take the time to use the photos to explain everything to you better.
Here's a great You Tube video giving you a basic overview of elbow anatomy.
The elbow is a hinge joint made up of the humerus, ulna and radius.
Your upper arm bone is the humerus and your lower arm bone is composed of two bones, the ulna and the radius.
The unique positioning and interaction of the bones in the joint allows for a small amount of rotation as well as hinge action. This rotation is easily noticed during activities such as hand-to-mouth eating motions.
The photos below show how these bones are positioned in the arm.
Here are a few more diagrams of the bone structure in the elbow area.
Here is a basic diagram of the elbow joint...
Below is a detailed picture showing the anatomy of your inner and outer elbow. Focus on the elbow muscles (Lateral Epicondyle)and the extensor tendons (they are marked tendons and circled in red on the diagram).
Below is another picture. This one details how the Lateral Epicondyle attaches to the humerus.
This area is the source of your tennis elbow, its one of the outer muscles of the arm.
Its key to note the Extensor Tendons noted in the diagram. These tendons and where they attach to the Lateral Epicondyle if the area where tennis elbow inflammation and tearing is bound to occur.
If you are really an elbow fan here's a very detailed You Tube video that goes into even greater depth and give a great review of the entire elbow structure including elbow muscles, extensor tendons, ligiments, joints etc.