Upper Extremity Sectional Anatomy

Objectives List structures found in sectional images of the upper extremities Identify sagittal, axial, and coronal planes from given anatomy Discuss the importance of understanding the relationships and locations between anatomic structures After completing this topic you should be able to: List structures found in sectional images of the upper extremities Differentiate between tissues and structures based on displayed density levels Identify sagittal, axial, and coronal planes from given anatomy Discuss the importance of understanding the relationships and locations between anatomic structures

wrist elbow As you review sectional images of the upper extremities, keep in mind the anatomy that is unique to them. Look at the axial image of a wrist and an elbow. Can you tell which is the elbow? <left image is elbow. I put labels that can be removed> The elbow is unique in that the trochlea sits in the trochlear notch and the olecranon process and the coracoid process make a hook around the trochlea. This makes the elbow easy to identify. <bring in labeled image of axial elbow> The wrist is made up of 8 tiny bones stacked together with no other bones around them except at both ends. In an axial view, you see these stacked together, kind of like pebbles or stepping stones. Also remember that the hamate has a hook. < bring in (top right) labeled image of axial wrist>

femur humerus femur humerus The images shown here are a little more difficult to identify because they can easily get transposed with the lower anatomy. For example, the humerus and femur, both being long bones, are pretty similar in mid shaft. These are NOT good choices to help identify the anatomy. <bring in top images > In these images can you tell the femur from the humerus? The humerus is on the left and the femur is on the right. <I used labels to help clarify, they do not need to be on the student version> At a quick glance, these look very similar. But if you look at the muscles surrounding the bone, you can see that the femur has more muscle around it than the humerus. Two other easily confused images are of the humeral head and the femoral head. <bring in bottom images > The humerus is on the left again. Both structures have round heads, and are ball-and-socket joints. The acetabulum has more of a base surrounding the femoral head than the glenoid fossa around the femoral head. The scapula can help you identify the humerus. Notice how thin that bone is? <arrow>

wrist elbow Coronal sagittal axial Anatomical structures are relatively easy to identify on coronal images of the upper extremities <bring in coronal image, can remove label>because these are the views which most resemble plain radiographs or anatomy drawings from a textbook <bring in hand image (remove labels)>. The sagittal images are also relatively simple to decipher, because the anatomy will resemble the lateral views of the same area. <bring in sagittal image, can remove label> In both the sagittal and coronal images, if the image is showing an area close to the edge of the anatomy, it will be more of a challenge because you are only getting a small part of the anatomy. The axial view <fade out other images, bring in axial image, can remove label> is puzzling because it looks very different from other views. The axial images of the hand /wrist seem to resemble a pea pod <bring in peapod, superimpose over axial, then fade out> or a meatball sub <bring in sandwich, superimpose over axial, then fade out> . sagittal axial

wrist elbow When viewing cross sectional anatomy, find some anatomy that you know, or that is characteristic of that area. Put the others parts of anatomy together from there. Don’t use the anatomy that can be similar with other areas.