Nerve

"The nerves can be seen through the skin."

"Some plants have ornamental value because of their contrasting nerves."

"He hasn't the nerve to tell her he likes her. What a wimp!"

"The web-team found git-sed is really a time and nerve saver when doing mass changes on your repositories"

"May their example nerve us to face the enemy."

"The liquor nerved up several of the men after their icy march."