The liver is the largest gland in the vertebrate body, composed of a spongy mass of wedge-shaped lobes that has many metabolic and secretory functions. It is a reddish-brown in color and is located in the upper right part of the abdominal cavity extending 3-4 inches to the left of the midline. It weighs about three pounds and is approximately 3-5% fat. It performs over 500 functions.
In humans the pancreas weighs approximately 80 grams, has roughly the configuration of an inverted smoker's pipe, and is situated in the upper abdomen. The head of the pancreas (equivalent to the bowl of the pipe) is immediately adjacent to the duodenum, while its body and tail extend across the midline nearly to the spleen. The bulk of pancreatic tissue is devoted to its exocrine function, the elaboration of digestive enzymes that are secreted via the pancreatic ducts into the duodenum.
Most oral contraceptives are "combination pills" containing a combination of the hormones estrogen and progesterone to prevent ovulation (the release of an egg during the monthly cycle). A woman cannot concieve if she doesn't ovulate because there is no egg to be fertilized. The Pill also works by thickening the mucus around the cervix, which makes it difficult for sperm to enter the uterus and reach any eggs that may have been released.