"One of the fundamental principles of the Workers' Compensation Act is that it is the employer's responsibility to provide all medical treatment reasonably required to effect the proper care and speedy recovery of injured employees." ( Bell v. Samaritan Medical Clinic, Inc. (1976) 60 Cal. App. 3d 486, 489 [131 Cal. Rptr. 582].) The legislative scheme "vests exclusive jurisdiction in the Board over any controversy relating to or arising out of the medical treatment of an injured employee." (Ibid.) A physician may petition the Workers' Compensation Appeals Board for relief if he/she is dissatisfied with the amount paid by the employer or its carrier. ( Id. at p. 490; Lab. Code, 5304.) It is a matter of paramount concern that an injured employee be protected from unreasonable charges. (Bell, supra, at p. 491.) Business and Professions Code section 2220 sets forth the duties and powers for the Division of Medical Quality: "Except as otherwise provided by law, the Division of Medical Quality may take action against all persons guilty of violating this chapter. the division shall enforce and administer this article as to physician and surgeon certificate holders, and the division shall have all the powers granted in this chapter for these purposes including, but not limited to: "(a) Investigating complaints from the public, from other licensees, from health care facilities, or from a division of the board that a physician and surgeon may be guilty of unprofessional conduct. The board shall investigate the circumstances underlying any report received pursuant to Section 805 within 30 days to determine if an interim suspension order or temporary restraining order should be issued. The board shall otherwise provide timely disposition of the reports received pursuant to Section 805. "(b) Investigating the circumstances of practice of any physician and surgeon where there have been any judgments, settlements, or arbitration awards requiring the physician and surgeon or his or her professional liability insurer to pay an amount in damages in excess of a cumulative total of thirty thousand dollars ($ 30,000) with respect to any claim that injury or damage was proximately caused by the physician's and surgeon's error, negligence, or omission. "(c) Investigating the nature and causes of injuries from cases which shall be reported of a high number of judgments, settlements, or arbitration awards against a physician and surgeon." The Medical Board's authority to investigate and commence disciplinary actions is contained in Business and Professions Code section 2220.5: "(a) the Medical Board of California is the only licensing board that is authorized to investigate or commence disciplinary actions relating to physicians and surgeons who have been issued a certificate pursuant to Section 2050. "(b) for purposes of this section, 'investigate or commence disciplinary actions' shall mean written, oral, or telephonic communication with a physician or surgeon concerning his or her violation of the Medical Practice Act. "(c) Written complaints that are subject to Section 43.96 of the Civil Code, relating to the professional conduct or professional competence of physicians and surgeons, shall be processed in accordance with that section." The authority of the Workers' Compensation Appeals Board is contained in the Labor Code. "The Division of Workers' Compensation, including the administrative director and the appeals board, shall have power and jurisdiction to do all things necessary or convenient in the exercise of any power or jurisdiction conferred upon it under this code." ( Lab. Code, 133.) In the workers' compensation arena, all proceedings "[f]or the recovery of compensation, or concerning any right or liability arising out of or incidental thereto" shall be instituted before the WCAB. ( Lab. Code, 5300, subd. (a).) "The Appeals Board is vested with full power, authority and jurisdiction to try and determine finally all the matters specified in Section 5300 subject only to the review by the courts as specified. . . ." ( Lab. Code, 5301.) "The appeals board has jurisdiction over any controversy relating to or arising out of Sections 4600 to 4605 inclusive" absent a contrary agreement. ( Lab. Code, 5304.) Labor Code sections 4600 through 4605 involve the duties of an employer providing medical care to an injured employee. Employers shall provide medical treatment that is "reasonably required" to treat an injured employee and are liable for the "reasonable expense" incurred by or on behalf of an employee. ( Lab. Code, 4600.)