"sheath" -
key terms from Wikipedia
bundle
sheath
bundle
sheath
cells
carotid
sheath
form
the
myelin
sheath
hair
root
sheath
cell
malignant
peripheral
nerve
sheath
malignant
peripheral
nerve
sheath
tumor
metal
sheath
myelin
sheath
optic
nerve
sheath
root
sheath
sheath
sheath
used