1. Shonda Rhimes was obsessed with watching surgical shows on the Discovery Channel.
2. But her idea for Grey's Anatomy really started to develop after a doctor told her how hard it is to shave her legs in a hospital shower.
3. Rhimes almost set Grey's Anatomy in her hometown, Chicago, but decided not to in order to not have the show feel too similar to another medical drama, E.R., which is set in the same city.
4. Grey's Anatomy was going to be called Complications.
5. Miranda Bailey was the only role written with a character description: "tiny blonde with curls."
6. She was loosely based off Rhimes' mother.
7. But when Chandra Wilson auditioned, Rhimes was convinced she was perfect.
8. Sandra Oh originally auditioned for the part of Bailey.
9. But Oh loved the character of Cristina Yang and asked if she could read for her.
10. Ellen Pompeo wanted to do a different ABC pilot, written by Bob Orci and Alex Kurtzman, called Secret Service. When that didn't get picked up, she was asked to play Meredith Grey.
11. When Patrick Dempsey first auditioned, he was terrified of Rhimes because of her stone-cold expression.
12. But Rhimes was actually trying to figure out what she could write for the, in her words, "dreamy" actor.
13. James Pickens Jr. got the part of Dr. Richard Webber just minutes after he auditioned. After he read, they asked him to step into the hall, and when they brought him back in, he was offered the part.
14. Isaiah Washington originally auditioned for the role of Dr. Derek Shepherd.
15. Though Washington didn't win that part, he got a call that the actor who had signed on to play Dr. Preston Burke had to drop out and the writers wanted him for the part.
16. The character Alex Karev (Justin Chambers) was added to the script after the pilot had already been shot, so all of his scenes were digitally implanted into the episode.
17. Rhimes started Meredith, Cristina, Alex, George, and Izzie as interns instead of established surgeons because she thought "there's something really horrible about not knowing what you're doing for a living."
18. Pompeo didn't know that Derek was married until the Season 1 finale was being filmed.
19. And Dempsey didn't know his character was married until halfway through the first season.
20. Kate Walsh was initially hired for only a few episodes, but she had such great chemistry with the cast that she was brought on full time and eventually given her own spin-off, Private Practice.
21. Like Izzie, Katherine Heigl likes to bake and knit.
22. Unlike her character Lexie Grey, who graduated from Harvard Medical School, Chyler Leigh dropped out of high school.
23. Jessica Capshaw auditioned for three roles on the show: first, Derek's love interest Nurse Rose (Lauren Stamile), then Meredith's crazy friend Sadie (Melissa George), and finally, she won the part of Arizona Robbins.
24. Arizona was originally just going to have a three-episode arc.
25. Bailey's infamous vagina euphemism "vajayjay" was actually coined by an assistant on set. When Rhimes heard it, she wrote it into the script.
26. Brooke Smith, who played Dr. Erica Hahn (a love interest for Sara Ramirez's Dr. Callie Torres), was let go from the show. She was told the writers could no longer "write for her character."
27. In order to make sure that the check Denny (Jeffrey Dean Morgan) left Izzie was readable after weeks of wear-and-tear — and food spills — Grey's propmaster Angela Whiting suggested just increasing the dollar amount.
28. When Derek writes his and Meredith's wedding vows on a Post-it note, Dempsey was actually writing down the things they were saying in that moment.
29. Pompeo got pregnant while filming Season 6, but instead of making Meredith pregnant as well, the writers had the character give part of her liver to her estranged father, Thatcher (Jeff Perry), so that Pompeo could be confined to bed rest to hide her pregnant belly under sheets.
30. A real program was printed up for George (T.R. Knight)'s funeral.
31. It was Oh's idea for Cristina to have an emotional breakdown, which led Rhimes to write the scene after Cristina loses her unborn baby and can't stop crying in her hospital bed.
32. Rhimes enlisted the help of Chandra Wilson, Sara Ramirez, and Kevin McKidd to put on a concert for some ABC producers to convince them that infamous musical episode in Season 7 would be a great idea.
33. In the musical episode, when Callie was singing over her injured body, they used a double and then just digitally mapped Ramirez's face onto the body.
34. Though most of Grey's Anatomy is shot on a sound stage in Los Angeles, Meredith's childhood home is a real house located in Queen Anne Hill in Seattle.
35. The roof of local ABC affiliate in Seattle, KOMO-TV, is used to film scenes when helicopters land on the roof of the hospital.
36. Jesse Williams (Dr. Jackson Avery) was a teacher before being cast on the show.
37. When Lexie was killed in the plane crash in Season 8, Leigh stayed under the actual wreckage for the better part of two straight days to film the scene.
38. When Arizona lost her leg, Capshaw "walked on a prosthetic with [her] own leg tied behind [her]" and editors digitally erased any overlap.
39. All the medical storylines are found in medical journals that the writers read or from stories that viewers send in that they find interesting.
40. When cast members "perform" a specific medical procedure during an episode, they are given tons of material to understand how it would be done in real life.
41. And Washington would actually learn how to perform all of his fictional surgeries before shooting them.
42. On set real cow organs are used.
43. There's also blood matter: red Jell-O, blood, and chicken fat.
44. And lamb brains have been used for some of the brain surgeries.
45. The MRI machine is real.
46. The names on the OR board are actually names of Grey's crew members.
47. Kevin McKidd (Dr. Owen Hunt) is Scottish.
48. He used his real accent in the 2008 film Made of Honor, which also featured his Grey's co-star Dempsey.
49. When Cristina finds out Owen cheated on her, she tosses a bowl of cereal in his face. But it took three takes to get the shot just right so McKidd was covered in milk.
50. A few months after it was revealed that April Kepner (Sarah Drew) was pregnant at the end of Season 10, Drew announced she was pregnant in real life.
This post has been corrected to accurately state that Ellen Pompeo, like Patrick Dempsey, has appeared in every episode of "Grey's Anatomy." Thanks to Ellen Pompeo for clearing that up!