The medical lab was a section aboard starships where medical research and experiments were performed.
The medical lab aboard the USS Enterprise housed, among other things, gossamer mice and halo fish. (TAS: "The Terratin Incident")
In 2269, following Spock's assertion that Leonard McCoy showed a lack of scientific interest while on Lactra VII, McCoy invited the Vulcan to his medical lab to discuss it with him. (TAS: "The Eye of the Beholder")
