telegraph

electrical impulses

hormonal

proteins

they do not have a nucleus

they help carry oxygen to different parts of your body

they regenerate very quickly

they are very long compared to other cells in the body

skin cells

liver cells

stem cells

muscle cells

1 meter per second

100 miles per hour

1 foot per second

150 meters per second

nerve

muscle

the brain

wire

prison cells

muscle cells

glial cells

stem cells

a nerve

all of the above

brains

spinal cord

Purkinje neurons

bipolar neurons

multipolar neurons

pyramidal neurons

1 month

1 year

10 years

100 years