Our example says that below, four pelvises are shown. Two are shown from the front and two are shown from above. In each view, one pelvis is from a female and one is from a male. We need to identify which pelvises we believe to be male and which we believe to be female. Then we need to indicate at least one anatomical feature that allowed us to differentiate the two by marking it on the picture. Alright. So we have two images here. The image on the left clearly shows two pelvises as we're looking down on them, and the image on the right, we have two pelvises from a front view or an anterior view.

Let's start with these two on the left. Which one do you think is more likely a male pelvis, and which one do you think is more likely a female pelvis? Well, when I look at it, the thing I cue in on is this shape here. As I look down through the pelvis, I'm going to circle this, and that's the shape of the pelvic inlet, that ring around the pelvis there. And this one on the left, it looks kind of round and kind of wide, especially when I compare it to this pelvis on the right. This pelvis on the right has that sacrum sort of coming underneath. As I draw that shape, it comes out much more kind of heart-shaped there. Right? That heart-shaped pelvic inlet, that's more likely to be part of a male pelvis, and that bigger, rounder, more oval-shaped pelvic inlet is more likely to be part of a female pelvic inlet. So what's the anatomical feature we use to identify that? We use the pelvic inlet.

Let's look at these two on the right. Take a look. Which one do you think is more likely male? Which one is more likely female? Well, when I take a look, what I notice is that this pelvis on the left, it's pretty tall, and it's also relatively narrow, at least for how tall it is. Well, this one on the right, that's pretty short, and it's very wide, again, at least for how short it is. And I remember that a tall, narrow pelvis is more likely to be a male pelvis, and a shorter, wider pelvis is more likely to be a female pelvis. But the thing that really cues me in here is something else. And that's when I look at this, I look at this angle right here. That's the angle of the pubic arch. And do you see on that pelvis? It's a real sharp angle. It's an acute angle. Whereas on this pelvis, it's very wide, or rather, it's an obtuse angle. All right. That sharper angle is more likely to be part of a male pelvis, whereas the wider or obtuse angle is more likely to be part of a female pelvis. And the anatomical structure that I use to identify that is the shape or rather the angle of the pubic arch.

With that, we've answered the question. More problems to follow. Give them a try.