Definition of "midgut" [mid•gut]

• The middle section of the digestive tract in a vertebrate embryo from which the ileum, jejunum, and portions of the duodenum and colon develop. Also called mesenteron. (noun)
• The middle portion of the digestive tract of certain invertebrates, such as arthropods, lined with an enzyme-secreting tissue and serving as the main site of digestion and absorption. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The most important organ in the crustacean is what biologists call the midgut gland or hepatopancreas, and what the rest of us usually call the “liver.”"
• "The midgut is the next part of the gut, which the food passes through."
• "The midgut is the first major region of the body where blood and microbes ingested with the blood meal come in contact with the tick's internal tissues."