So our stomachs growl when we're hungry, our mouths feel dry when we're thirsty, we yawn when we're tired.  But how the hell do these things actually happen, and what role does our brain play in directing the whole operation?

 

 

Hunger! There are approximately 1.2 million absolutely fascinating studies and hypotheses about what turns your appetite switch on and off, and we will cover every single one of them, especially the ones involving blood transfusions between dogs and the swallowing of balloons. 

 

Thirst! We might be 70% water, but we wouldn't last very long without knowing when to drink more. Let's figure out how your body knows when to drink, and how it tells you you've had enough. Other cool facts to be learned: did you know your ability to detect thirst declines with age?  

 

Sleepiness! They say that after you've been awake for 20 hours, your reflexes are about the same as someone who is legally drunk.  Why do we yawn more in the morning and at night?Why do we sleep in the first place? 

We'll try to get some answers in class.  Here are places to start: this article about your basic drives is way too long, but go for it. 

Also long, but this blog post on why we sleep has weird pictures of things sleeping!