1 year

1 month

10 years

100 years

stem cells

skin cells

muscle cells

liver cells

they help carry oxygen to different parts of your body

they are very long compared to other cells in the body

they regenerate very quickly

they do not have a nucleus

muscle

the brain

nerve

wire

muscle cells

glial cells

prison cells

stem cells

bipolar neurons

pyramidal neurons

multipolar neurons

Purkinje neurons

hormonal

electrical impulses

proteins

telegraph

1 foot per second

150 meters per second

100 miles per hour

1 meter per second

brains

a nerve

spinal cord

all of the above