eruvin 7

when something is missing, the status changes

if a corpse is missing a vertebra or two, then it is just a pile of old bones.
and
if the back wall of an alley is breached to open space where people have not come together to make an eruv, can no longer carry.

shabbat 94

human dignity
looking after the body can overturn even a torah prohibition
from carrying a corpse
to removing a severed hanging fingernail

(for english translation of this talmud page, see here)

shabbat 83

trying to untangle the threads of connection between idolatry and different sources of impurity can lead one to despair.

that's ok. Reish Lakish says that engaging in Torah should be something that you could kill yourself over.

(multi-stranded lines of discussion about what type of impurity is idolatry, comparing it to a niddah, a corpse, a zav, a gentile man or woman, a creeping insect, animal carcass.... trying to follow the arguments got confusing but thankfully Reish Lakish thinks that the Torah that endures is the type of learning that really pushes the limits. for full english translation of this page of talmud, see here)