Master Plan

A quick random note: Thanksgiving break was amazing...did nothing but sleep, eat, and drink. Very much needed, most definitely enjoyed. Aaand now the slap in the face that is med school welcomes me back this week. Ah well.

A little over a week after our anatomy exams, I'm left feeling 1.) still a bit violated 2.) amazed at the body. I'm choosing to focus on the latter.

As part of anatomy, we cover some embryology. In doing so, we learn about how some of the major organ systems develop. And in taking a step back, it's actually kind of amazing how things happen. The four chambered heart that we know and love starts out as a tube. And through some magical signaling, the heart decides to fold a few different ways, along with different partitions appearing out of nowhere. And then you have yourself a heart. The development of the respiratory system is not as complex, but is linked to a bud from the esophagus. The entire respiratory system. From a bud off the esophagus. The lovable domed muscle that is the diaphragm has four different structural embryological origins that converge to form it. The abdominal contents all develop with a certain initial embryological relationship. Throughout fetal development, the intestines, mesenteries, and viscera are rotated and shifted - leading to landmark structures and spaces that persist in adults. I guess the main thing that I'm getting at is it's pretty amazing how things can change so much from fetus to adult.

Even more awesome is how all this development and rearrangement occurs without a hitch most of the time. The first thing that comes to mind is the heart. There are in an insane number of ways that heart development could mess up. There are the more "common" defects including specific ventricular and atrial septal defects, along with patent ductus arteriosus. There are a lot of stages where kidney and urogenital development can go wrong as well. Similar stories are true for the other organ systems as well.

Another thing that amazes me (in hindsight) is the complexity of the autonomic nervous system. Seriously, working through how different areas/organs are innervated and interact was a task. The way nerves off the spinal cord rearrange into sympathetic chains and then proceed to recombine with other sympathetics, parasympathetics, and/or somatics...still not sure if I fully understand it all. And the nerve plexuses. (I maintain the plural should be plexi, but that's my own battle). I don't appreciate anterior rami nerves' need to branch apart and rearrange into different distinct nerves. *ahem - brachial, lumbar, and sacral plexi* And naturally, the abdominal autonomic system felt the need to follow a similar path...celiac, inferior mesenteric, superior/inferior hypogastric plexi.

I suppose what I'm getting at with all this is I'm amazed at the human body. Science intrigue from a med student?? Shocking, I know. But seriously. The more I learn about medicine, especially anatomy and physiology, the more I wonder...damn, evolution (powers that be/intelligent design) is a smart cookie.