A blister is a small bubble on the skin filled with clear fluid. This is caused by friction and the rubbing of a material against the skin.
This is a chronic injury due to the blister having to be created over time and not caused instantly.
Sign of a blister is seeing the bubble of skin
Symptom of a blister is the discomfort feeling of the area of where the blister is.
This can commonly occur for long distant runners on their feet. This is due to the constant running and rubbing of the feet against the shoe and sock.
source of image: https://olaasm.wordpress.com/2014/02/21/the-blister/
Laceration is more serious than abrasion. This is a deep cut or tear to the flesh and skin.
A laceration is a acute injury this is because it is instant and is noticeable straight away.
A sign of this is blood coming from the wound. Also seeing the cut.
Symptom of a laceration is the pain around the area of the cut.
A sporting example of this could be Ice hockey. This could be due from being cut with the blade on the bottom of the ice skating causing to deep cut or the tear the skin/flesh.
Source of image: https://twitter.com/wtfgifspics/status/621224454488616960