A panel of federal judges in Manhattan upheld the 10-year prison sentence imposed on Lynne F. Stewart, the disbarred lawyer convicted in a terrorism case who had been resentenced to that term after boasting that she could do a much shorter sentence “standing on my head.”

Judge Robert D. Sack, writing for a three-judge panel of the United States Court of Appeals for the Second Circuit, dismissed Ms. Stewart’s arguments that the judge who had resentenced her to 10 years in prison had penalized her for comments she had made, in violation of her First Amendment rights, and that the new sentence had been too severe.

“From the moment she committed the first act for which she was convicted, through her trial, sentencing and appeals,” Judge Sack wrote, “Stewart has persisted in exhibiting what seems to be a stark inability to understand the seriousness of her crimes.”

He added that she had also failed to understand “the breadth and depth of the danger in which” her crimes had “placed the lives and safety of unknown innocents, and the extent to which they constituted an abuse of her trust and privilege as a member of the bar.”