Facial Anatomy Lesson

The only drawing I've done today.  I watched a lesson on facial anatomy.  I'll probably need to watch it again at some point, could have paid it better attention than I did.  Even so, I think it really improved my understanding of the forms that comprise the head.

Here are some of the main points I remember:

-the basic forms of the face have key points defining them (like how you can easily define a cube by it's vertices)

-the corners of the eyesockets and cheekbones form a rectangle; from these points going to the back of the head a fairly flat plane is formed on either side of the head

-when defining the eyebrow/nose area, there's a specific number of points a person has here (creating planes/lines inbetween these points), these points are arranged in a large variety of ways between people

-the basic mouth area shape is very similar to a half sphere; the teeth are arrayed in a u-shape, a lot narrower than you may think at first

-a way of thinking about drawing the lips is imagining a bird with wings spread sitting on top of an egg

-basic skull shape is egg-like, wider at the back than the front; the profile of the head fits nicely into a rectangular shape that can be divided to place the features of the face (general placement)
(half-way down are the center of the eyes, half-way from eyebrows (not the eyes!) to chin is the bottom of the nose, half-way between the nose bottom and chin is the bottom of the lower lip)

-thickest part of the nose connects at the cheekbone

-the nostrils are basically cup shaped, with a very large variety of nostril sizes, shapes and orientations

-the end of the nose cartilage tapers to a point; the cartilage forms a triangle as it meets the cheekbone on either side

-there's a small change of plane direction between the nose and eyesocket, resulting in value change

-the outer corners of the eyesockets and the eyebrows are often mistaken as the same thing, the eyesocket fits into the bottom of the brow

-the eyelid, while thin, still has a thickness that should be defined; various folds can occur where the eyelid meets the eyesocket and cheekbone

(I should do this with the other tutorials I have..)

...

I suppose I don't really have any explanation for this.