One day your friend, Luís, who has always been somewhat short, comes up to you and says, “Okay, you A&P expert, I have a question for you! I exercise lots, eat calcium rich foods, and take vitamin D supplements, but I never get taller! Clearly my bones can grow, since I had a little growth spurt in high school, but I’ve been pretty much the same height ever since then. What was going on with my bones back then that isn’t happening now and why?” You sigh and pull out your A&P book to try to explain. How do you respond to Luís? Use the words “chondrocyte,” “osteoblast,” and “estrogen” in your explanation.
