Some tissues continue to stem cells after it become specialized, but
these cells are less flexible than embryonic stem cells, Embryonic
stem cells are pluripotent Meaning that they are capable to become any
of the more than 200 types of speciality cells of our body (heart
muscle cells, skin cells, nerve cells) When a tissue get diseased or
damaged Stem cells in theory can replace or repair tem.

Scientist often extract the stem cells from a organism prior to birth
which destroys the organism, But once stem cell is harvested they can
live on their own in lab copying themselves and create a lineage or
line for future research in areas like spinal cord injury.

Spinal cord injury is incredibly complex, When spinal cord injury
occurs many things go wrong simultaneously or with short notice, When
stem cells are attracted towards these area of injury what it may do
is to read the some of 'Q's and become missing nerves cell or stem
cell may provide a bridge between spinal cord,