Chapter 5

Chapter 5 was the most interesting read for me so far in the book. As Jaime said, I had always known that our heads were complicated structures, and was not too sure what to expect Shubin to talk about since there is much to talk about when it comes to our heads. I was baffled when in the start of the chapter, Shubin stated that "their complicated pattern boiled down to something so simple, so outrageously easy that [he] saw the human head in a new way" because it seemed impossible that such a complex structure would ever be seen as simple and easy to understand.

However, Shubin's explanations of how our nerves connect from our brain to different parts of our body made the complex concept easier to understand. It's amazing how only twelve nerves are the cranial nerves. The complicated trigeminal and facial nerves breaking up into branches was interesting to read about. It was fun reading and finally fully understanding how anesthetic at the dentist works, because I had always wondered. As I read about the facial nerve and the "wonderfully evocative names" of the tiny muscles we use to control certain parts of our faces, my siblings looked at me strangely as I demonstrated the actions listed and stated aloud the muscle I was using (85). (example: I frowned, and excitedly said that I was using my depressor anguli oris)

I was also excited to find out the reason why people are always very careful with babies' heads, how when we're born, the plates that form our cranium are separate and the fontanelles are seen in infants until about the age of 2.

Seeing yet another relation to sharks was interesting. As Jason said, the picture on page 91 comparing human and shark embryos was amusing because of the close similarities between them.

Francine Castillo