Urea, together with water and other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney. From the kidneys, urine travels down two thin tubes called ureters to the bladder. The ureters are about 8 to 10 inches long. Muscles in the ureter walls constantly tighten and relax to force urine downward away from the kidneys. If urine is allowed to stand still, or back up, a kidney infection can develop.
SAGITTARIUS (November 23-December 21) LUCKY DAY: Thursday THE per fect woman for a Sagittarian man is a Gemini - which is why Brad Pitt and Angelina Jolie are Hollywood's golden couple. Celebs with stars in their (sex) lives; New PEOPLE astrologer Claire Petulengro takes a look at what 2009 holds for some of the biggest names
Pi Approximation Day. Because everyone should be able to enjoy a fun mathematical holiday, people in countries that follow the day/month (dd/m) date format honor pi on Pi Approximation Day. The date of Pi Approximation Day - July 22 - when written in the day/month format or 22/7 corresponds to the fraction (22/7) that pi is usually depicted as. There are many other days during the year when one can honor pi. Some of these are: March 4: The day marks the passing of 14% of the 3rd month of the year.