I had my adenoids removed when I was 5 years old but i don’t know what they are or what they do.
I have gotten along fine without mine for 30 odd years so they can’t be that important, can they?
I believe they’re the same type of tissue as the tonsils, except located at the back of the throat. So when you have tonsillitis (sp?), the adenoids usually swell too. They’re usually removed at the same time too.
I was disappointed when I heard I was going to have a T&A. I thought that meant tits and ass. 
Wrong thinking is punished, right thinking is just as swiftly rewarded. You’ll find it an effective combination.
Great question, I have had the exact same experience, removed when I was five, with my tonsils, always wondered what they are.
Wisdom is the boobie prize,they give you when you’ve been --unwise!
ad.e.noid (noun)–lymphoid tissue growth in the nose above the throat that when swollen may obstruct nasal breathing, induce postnasal discharge, and make speech difficult (like the Nanny).
They don’t do much, except cause trouble.
I’ve always been told that they’re the opposite of subtractenoids. (insert rimshot here)
I’ll just go hide in that corner over there now 
Also, they usually shrink away completely usually around adolescence.
They do more than just cause trouble. They do the same as tonsils (filter germs for a sample so that the immune system can get a start on fighting them) but from a different area. This is the part where I’m not sure about. I know that the tonsils sample from germs coming in the mouth. I believe that adnoids sample from germs coming in the nose but I don’t quite understand exactly where they are so I could be wrong. I just know that the first is true because we researched the subject before deciding whether our daughter should have her tonsils and adnoids removed.
From What Is the Purpose of Tonsils and Adenoids? Includes diagrams.
"Tonsils and adenoids are composed of tissue that is similar to the lymph nodes or “glands” found in the neck, groin, and other places in the body. They are part of a “ring” of glandular tissue encircling the back of the throat. The adenoids are located high in the throat behind the nose and soft palate (roof of the mouth) and, unlike tonsils, are not visible through the mouth without special instruments. The tonsils are the two masses of tissue on either side of the back of the throat.
Tonsils and adenoids are strategically located near the entrance to the breathing passages where they can catch incoming infections. They 'sample" bacteria and viruses and can become infected themselves. It is thought that they then help form antibodies to those “germs” as part of the body’s immune system to resist and fight future infections.
This function is performed in the first few years of life, but it is less important as the child gets older. In fact, there is no evidence that tonsils or adenoids are important after the age of three…
There is a popular myth that tonsils and adenoids filter bacteria out of what we swallow and breathe, somewhat like a kitchen strainer. This is untrue."