These are blood vessels that carry blood back to the heart from the rest of your body. They are made up of different layers in a tube, like arteries, but are not as strong.
If you can’t breathe on your own after an operation or an accident, you may be put onto a ventilator. This is a machine that does your breathing for you.
The bones that make up your spine. Each vertebra has a hole in the middle so that the spinal cord can pass through it. You have 33 vertebrae in your spine.
A type of germ that can cause disease. Viruses cause colds, and more serious diseases like meningitis. Antibiotics don’t work against viruses so there’s no point in taking them for things like a cold.