I am a teacher, and I don't know what your pancreas does. I have a degree in education, neither primary or secondary, but in the rather niche field of adult education. Something that I am not currently employed in, but something that I find to be a vocation. As for the pancreas, I shouldn't say that I am totally unaware of its function. It is an endocrine organ, or maybe an exocrine one, depending on how you want to view the topology of it. It is right below the stomach, and releases enzymes into the small intestine that help digest food. One of the most important of these being insulin. So I don't know much about the pancreas. Don't ask me for advice on it.
A Medical Doctor can tell you all about your pancreas, using complicated latin and biochemistry, and about even more obscure parts of your body, little invisible organnelles deep within your cells. They can tell you how little things you don't know existed can change your life. Somewhere there is an enzyme that adds or removes a methyl group from a cholesterol molecule, and that can determine whether you will be healthy or very sick.
The other great professional fraternity, lawyers have a similar advantage. Sometime back in the 1930s or 1830s, someone's horse kicked over a barrel of herring, causing someone's oxen to plow through a fence, and because your lawyer knows that, when you hit a shopping cart full of 50 dollar bottles of wine with your Geo Metro, you aren't legally responsible. I just made that case up: I know much less about case law than I do about the pancreas.
As a teacher, I know lots of things, but they are certainly more prosaic. I know when to be sympathetic to a student, and when to tell them they need to try harder. I know the difference between a learning disability and underexposure to language and math. I know three different ways to explain the principle of cube/area relationship. I know that if someone says they are "not good at math", that they probably don't have a learning disability, but just a culturally-sanctioned aversion to math. I know that emotional and cognitive development are often not at the same stage. I know that even a dedicated student is going to watch the clock on a Friday.
All of these (and many others) are important skills to know. They take context, perception, empathy, theoretical knowledge and common sense. They are not, however, skills that are in anyway esoteric. I can claim to have these skills, but so can just about anyone. I can not demonstrate my membership in some fraternity of cognoscenti based on specific, technical knowledge.
There are all sorts of political and social implications of this, although I don't want to get into them, anymore than I quite want to go into quite how depressing my own life is right now. I do think that teaching and education, as a profession, gets less respect from society than the medical and legal professions (although the legal profession gets a very backhanded respect). I think that teachers and other educational professionals don't even treat each other with respect, and I think that all of this is due to the fact that while teaching takes much skill and subtlety, and much education and practice, it is also a vocation that takes more "soft skills" than many other professions. While I could make many arguments and implications about this, right now I will just leave this as an observation.