Week 1 Overview 2

We start with a look at the lungs and respiration. Oxygen in, carbon dioxide out! Lots of interesting structure in this system, starting at our sinuses, whose main role seems to be to get infected. We discover the clever trap door that keeps our food out of our lungs, except when it doesn’t; and learn how our lungs fill and empty, which is pretty much the same way as a blacksmith’s bellows. Wonderful though the lungs are, they are quite easily damaged.

We talk about some pathophysiology now: pneumonia, asthma, chronic obstructive pulmonary disease, pulmonary embolism, and more. Most of these can be controlled or treated, so it’s important to know something about their mechanisms, because they are, unfortunately, also very common. Then we’ll go on to the kidneys! They don’t get a lot of publicity,

but they get a lot of blood: 25% of the heart’s output goes through the kidneys. At the microscopic level, the kidneys

are a plumber’s dream: a million tiny blood filters, endless kilometers of tiny tubules, and a philosophy that says, “Filter most of it out, then absorb back the good stuff.” Because they see so much of the blood, the kidneys also make decisions about whether we need more red blood cells, or need to regulate our blood pressure, and even respond to changes in altitude.