Wednesday, February 06, 2008

Housewatch episode 4.12

Last night's solution to House was incredibly easy to understand, so I'll focus a bit on physiology instead.

The woman (Sarah Silverman's sister for those of you not watching the credits) had nephroptosis, or floating kidney. Everytime she stood up, her kidney slid down lower into her pelvis. She lost blood pressure, and she fainted and her breathing stopped. It's called orthostatic hypotension. The kidney is suspended in the pelvis by connective tissue. It can move easier than most organs. Since we can bend at the waist, this is a good thing.

So, why were they saying everything was backwards? In a healthy person, when you stand up your heart rate and blood pressure go up a little. If they didn't, you'd faint. With the head now above the heart, it takes more work to get blood to the brain, so the heart pushes a little harder, and then circulatory system tightens up a little, so the blood is less likely to trickle backwards.