My Old Roommate ...and the Sternocleidomastoid Muscle.

This particular post is a shout-out to my awesome undergraduate roommate. I really miss him and wish that his daily activities were the background noise for my studying. I had pizza tonight and thought of his, Tony, and I's late-night pizza runs across the street (and I recall those trips to the $5 place across from our old apartment too). I want to wish my former roommate a great evening (but I'm sure he is having one because I know his favorite TV show is on tonight).


In Anatomy news...

Remember when you get drowsy and feel yourself "nodding off" while in class, reading a book, or watching a movie? Remember how funny it is to see someone else falling asleep in public, with their head sagging? You see their head tilt back and forth, and then eventually hang as they snooze. Well, the expression "nodding off" is appropriately named because when you start to drift into sleepy-land, your head starts to "nod" as it sags back and forth. When you do drift off, your head hangs as a result of the relaxation of the sternocleidomastoid (SCM) muscle. This muscle, which can be felt protruding slightly out, and on either side, of the neck, is responsible for holding the head in an upright position. Our head is not balanced on our neck properly; most of the weight of the skull is concentrated towards the back of the head. In order to keep our head balanced, the SCM muscle has to pull forward to keep the head upright. You are able to lift your head off the pillow in the morning due to the SCM muscle being "woken-up" and contracted. On the other hand, when you feel yourself falling asleep, the SCM muscle is relaxing too, hence the sagging, unbalanced head.