two of my spring retainers are broken, one is broken in half and the other one just came off. i cant see any of the intake valves in these. so what im asking is what could of casued this? how bad is the damage? what should i do?

http://img517.imageshack.us/img517/7769/006gr4.jpg

http://img147.imageshack.us/img147/1465/007cb6.jpg

http://img147.imageshack.us/img147/4519/010pf9.jpg

http://img147.imageshack.us/img147/2249/008ed2.jpg