Henderson's 3-pointer gave the Rebels the lead and his two free throws with 21 seconds left produced a five-point Mississippi advantage, finally ending the Volunteers' upset bid.
Tennessee led for much of the contest, seizing a seven-point halftime advantage after holding the Rebels to 18 points in the opening period.
Mississippi stayed unbeaten in five Southeastern Conference games and is 16-2 for the season, having won eight in a row.
Henderson scored 28 points to lead the Mississippi comeback. Reginald Buckner was the only other member of the Rebels in double figures with 10 points.
Tennessee (9-8, 1-4) was paced by Jordan McRae with 26 points. The Rebels shot just 36 percent from the field, but they forced 21 turnovers while committing 11.
Lytro unveils camera that can focus a photo after shooting it
'How to Train Your Dragon 2' releases 5-minute clip