Each member of the public employees retirement board, upon assuming office, shall take an oath that the member will support the constitution of the United States and the constitution of the state, and that the member will diligently and honestly administer the affairs of the board and that the member will not knowingly violate or willfully permit to be violated any provision of this chapter. Such oath shall be subscribed to by the member making it, and certified by the officer before whom it is taken, and shall be immediately filed in the office of the secretary of state. A majority of the members of the board constitutes a quorum. All meetings of the board shall be open to the public except executive sessions as set forth in division (G) of section 121.22 of the Revised Code, and any portions of any sessions discussing medical records or the degree of disability of a member excluded from public inspection by section 145.27 of the Revised Code.