Hi Shelina:
You've got a point that some topics are more difficult to use the field trip or guest speaker. This activity is a tool, and as a builder, not every tool is used all the time.
That said, for medical terminology, here are a couple of idea for speakers:
1. Try to find an experienced medical records transcriber who could share numerours blunders, misspellings, and maybe even a few humorous blunders they've encountered over the years.
2. Identify an experienced medical professional who has experienced years of reading poor handwriting, incorrect spellings, and examples where incorrect terminology led to mistakes or (possibly) medical errors.
3. If you are covering a specific organ system, you might find someone in your community who works directly or indirectly with at least some patients related to this organ system. They might have some experiences to share where they would utilize the terminology commonly encountered in that specialty system.
4. Some terminology referes to instruments, procedures, and disorders. How about getting a sales representive that sells related products, is a local expert in providing services (medical or non-medical person).
5. How about a longtime patient brought in to talk about their disease or ailment. You could coach the patient to make sure to mention certain terms, and have your students listen for key words that you could ask about later.
Perhaps some of these ideas will work for you, or will stimulate your thinking about resources for guest speakers.
Regards, Barry