Biology Riddles

I am like thunder in your cranium. What am I?

What runs but cannot walk?

Raise your right appendage high above your head. Turn your head to the right and you will smell this.

This small creature kills even the largest one. What is it?

Everyone claims to know a way to stop these involuntary contractions but none of them work.

What Botox will do to your expression.

Deposit red liquid in me. What am I?

These are the bumpy parts of your digits.

What is something you can hold without ever touching?

You can break me, and I still work. If you touch me, you're mine. What am I?

I do not have eyes but I once could see. I used to have thoughts but now I'm empty. What am I?

I live next to beauty trying to catch your eye.
Grab me without looking, and you're surely to cry.
What am I?

Different lights do make me strange, thus into different sizes I will change.

Everyone loses us as a child, and neglecting us makes us holy. What are we?

I am rarely touched but often held, and if you are smart you'll use me well. What am I?

A vessel have I, that is round as pear, moist in the middle, surrounded with hair; and often it happens that water flows there.

The only amusing part of the body. What am I?

I am the reaction after enjoying soda. What am I?