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.
Longbow?
O think the ears
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
?
Nothing on TV