You should look Andrew Loomis for structure, he has a book anatomy and face. It should help you ton in understanding the human anatomy and structure; I, myself also have trouble with anatomy when it comes to drawing people.
Hi, and welcome to CA.
What you labeled as gesture drawings look more like outline drawings to me. Gesture drawings usually focus on the rythm and flow in the motion while accurate anatomy is being neglected to a certain degree.
I suggest you to take a look at Stan's explanation and examples on the subject: http://www.youtube.com/watch?v=74HR5...rMz_Y9Fbw_d2ws
Hey Ali... or, erm, Agent Seems like it's been a while since you posted here. It's hard to keep up something like that right? I can relate... I only recently decided to pick up my sketchbook again. Mostly for the sake of self reflection and putting myself out there.
You haven't posted here in a couple of months but I hope you come back! We should talk on Skype some time, I think it would be interesting to share our experiences. I vaguely remember you telling me we had similar backgrounds as well. I moved to the UK about a year ago now, and I'm settling in great.
I hope you've been continuing studies in the meantime because what I see here is a fantastic improvement from your previous sketchbook.