Words describing injuries

[Proalyssa199]

Hi,
Can anyone explain to me the difference between bruise, blister, scratch, graze, gash, sprain, fracture?
Which one is the most suitable in these sentences?
-He fell on the pavement and ... his knee. I've washed and dressed it but it isn't serious.
-My feet are all ... after my attempt at the marathon yesterday.
-He landed awkwardly after the high jump and ... his ankle. He's lucky it's not broken.
-That's not a cut - it's just a ... Don't make such a fuss!
-I caught my leg on the drawer of the filing cabinet and it gave me quite a nasty ...
-The X-ray showed that I had ... several ribs in the accident.
-She fell down the stairs and was lucky to get away with a few ...

Many thanks to your help. :)

[Conchita]

This is when a dictionary comes in handy:

http://dictionary.cambridge.org/

[Lost_Soul]

I want to have a crack at this.

-He fell on the pavement and grazed his knee. I've washed and dressed it but it isn't serious.
-My feet are all blistered after my attempt at the marathon yesterday.
-He landed awkwardly after the high jump and sprained his ankle. He's lucky it's not broken.
-That's not a cut - it's just a scratch Don't make such a fuss!
-I caught my leg on the drawer of the filing cabinet and it gave me quite a nasty gash
-The X-ray showed that I had fractured several ribs in the accident.
-She fell down the stairs and was lucky to get away with a few bruises

If our native English speakers took the time to check it ... I would be immensely grateful :)