Any corporation may, by its bylaws, provide for an executive committee to be elected from and by its board of directors. To such committee may be delegated the management of the current and ordinary business of the corporation, and such other duties as the bylaws may prescribe, but the designation of such committee, and the delegation thereto of authority, shall not operate to relieve the board of directors, or any member thereof, of any responsibility imposed upon it or him by sections 70-701 to 70-738.