The spinal cord.
the av bundle (aka Bundle of His (pronounced like 'hiss'))
On old Olympus towering tops a Finn and German viewed some hopps
no o~o
Gftoa unscrambled is f a g o t, which means a bundle of sticks.
The brain teaser "0 over silver" refers to the letter "O" (which represents zero) being placed over "silver," which is often associated with the chemical symbol "Ag." When combined, it forms "O over Ag," which phonetically sounds like "O over a G." The answer is "O" (zero) over "Ag," leading to the interpretation or pun that emphasizes the sound rather than a mathematical operation.
O think the ears
Longbow?
The answer to the brain teaser "an in o in job" is "on." The phrase suggests looking for a word that fits within the context. Here, "an" and "o" are located "in" the word "job," and if you take "o" from "job," it leaves "j" and "b," which can lead to the interpretation of "on" as a clue.
I envented it with a brain o the year 1554
The answer to the brain teaser "O ER T O" is "TOO". The letters can be rearranged to form the word "TOO", and the clue suggests a hidden meaning by indicating that the letters represent something that is "over" or "too much." The "O" at the beginning and end reinforces this concept.
"All" mixed up
Encephalopathy: encephal/o means brain, -pathy means disease condition. The general category for the degenerative diseases of the brain is known as "dementia". Alzheimer's Disease account for about two thirds of all dementias. There is also vascular dementia, dementia due to Parkinson's Disease, normal pressure hydrocephalus, Creutzfeldt-Jacob disease, and many others.