Credit: Richard Cartwright/ABC Television Group © 2011 Disney Photo: Meredith, Cristina, Jackson, Alex, and April on Grey's Anatomy September 29, 2011

Sometimes we think the writers of Grey's Anatomy just put in big, fancy-sounding medical terms just for fun. Lucky you have us to speak slowly and gently so that you can actually learn the science behind the show. Here's the lowdown on this week's batch of surgical lingo from Season 8, Episode 3 "Take the Lead."

What was wrong with Alex's (Justin Chambers) patient Sam? If anyone missed April’s (Sarah Drew) motor-mouthed diagnosis, chronic mesenteric ischemia is an inflammation and injury of one’s small intestine due to a lack of blood supply. Sure is a simple definition for a very complicated sounding condition. It's only treatable by a laparotomy, an operation involving a large incision in the abdomen of the patient.

The patient on whom Cristina (Sandra Oh) was originally supposed to operate had problems with her mitral valve, a flap inside one’s heart that controls the flow of blood and is located between the left atrium and left ventricle, two of the four chambers in the human heart responsible for receiving oxygenated blood. A wonky mitral valve causes blow to flow back into the left atrium, which simply will not do.

Jackson (Jesse Williams) worked with an infant with a cleft lip and palate, a condition that occurs in about one of every seven-hundred births worldwide. Commonly known as a harelip, a cleft lip/palate is formed in utero during the development of the embryo's head. Due to the risk of infection as well as the potential for speech deficits and difficulty eating, parents usually opt to have their child's cleft lip/palate corrected surgically. Though there seem to be some hereditary links, the cause of the cleft lip/palate is not completely known.

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