[Tdol]

Originally Posted by Ryan

I have read somewhere that we usually use 'the' when we talk about body parts, for example - 'The brain is the most important organ in the body.'

My question is: Do we also use 'the' with other body parts (in plurals) such as legs, arms, fingernails, ears, eyes, body cells, kidneys, red blood cells, etc.?

? The fingernails are made of a type of protein called keratin.
? Fingernails are made of a type of protein called keratin.

Thanks
Ryan

I agree with Red about the plurals, but would also add that when we are talking about our own body, or a specific persons, we generally use possessive adjectives: He's been having troubles with his kidneys recently.