Cache invalidation in Blockcache

[chandra kant]

Hi,
I have Blockcache enabled on my table. So, I read a row and it's stored in
Blockcache . Next, I do a write on that row and I read it again .
My question is -  does writing that row invalidates the entry of that row
in Blockcache ?
Also, while reading , does RegionScanner first check memstore for any
updates regrading that row or Blockcache ?
It's quite confusing from what  I have read..
Thanks
Chandra