When whales swallow food, it travels through the esophagus to a multichambered stomach that resembles the stomachs of ruminant hoofed animals such as cattle, sheep, and deer. In the first stomach chamber, a saclike extension of the esophagus, food is crushed. In the second chamber, digestive juices further break down food. Most cetaceans have a third stomach chamber, which regularly contracts to mash and thoroughly mix food with digestive juices. The stomach capacity of a large whale can reach 760 liters (200 gallons).
From the stomach food moves through the intestine, where nutrients pass through the intestinal wall and are absorbed into the blood. Remaining waste materials are eliminated through the anus into the ocean. Cetaceans lack two internal organs found in most land mammals: the gallbladder and appendix.
D. Sense Organs
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