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                                                                    Exhibit 3.66

                                     BY-LAWS

                                       OF

                     SOUTHEASTERN EMERGENCY PHYSICIANS, INC.

                                    ARTICLE I
                             MEETING OF SHAREHOLDERS

         1. Annual Meeting. The annual meeting of the shareholders shall be held
at such time and place, either within or without this state, as may be
designated from time to time by the directors. Unless the time is otherwise
specified by the directors, said meeting shall be held on the first Monday in
December of each year, or as close thereto as practicable. [T.C.A. 48-701(1),
(2).]

         2. Special Meetings. Special meetings of the shareholders may be called
by the president, a majority of the Board of Directors, or by the holders of not
less than one-tenth (1/10) of all the shares entitled to vote at such meeting.
The place of said meetings shall be designated by the directors. [T.C.A.
4E-701(3).]

         3. Notice of Shareholders Meetings. Written or printed notice stating
the place, day, and hour of the meeting, and, in the case of a special meeting,
the purpose or purposes for which the meeting is called and the person or
persons calling the meeting, shall be delivered either personally or by mail by
or at the direction of the president, secretary, officer, or person calling the
meeting to each shareholder entitled to vote at the meeting. If mailed, such
notice shall be delivered not less than ten (10) nor more than sixty (60) days
before the date of the meeting, and shall be deemed to be delivered when
deposited in the United States mail addressed to the shareholder at his address
as it appears on the stock transfer books of the corporation, with postage
thereon prepaid. If delivered personally, such notice shall be delivered not
less than five (5) nor more than sixty (60) days before the date of the meeting,
and shall be deemed delivered when actually received by the shareholder. The
person giving such notice shall certify that the notice required by this
paragraph has been given.
[T.C.A. 48-703(1).]

         4. Quorum Requirements. A majority of the shares entitled to vote shall
constitute a quorum for the transaction of business. [T.C.A. 48-102(q).] A
meeting may be adjourned despite the absence of a quorum, and notice of an
adjourned meeting need not be given if the time and place to which the meeting
is adjourned are announced at the meeting at which adjournment is taken. [T.C.A.
48-102(q).] When a quorum is present at any meeting, a majority in interest of
the stock there represented shall decide any question brought before such
meeting, unless the question is one upon which, by express provision of this
corporation's Charter, these By-Laws, or by the laws of Tennessee, a larger or
different vote is required, in which case such express provision shall govern
the decision of such question. [T.C.A. 48-710; T.C.A. 48-804(2).)

         5. Voting and Proxies. Every shareholder entitled to vote at a meeting
may do so either in person or by written proxy, which proxy shall be filed with
the secretary of the meeting before being voted. Such proxy shall entitle the
holders thereof to vote at any adjournment of such meeting, but shall not be
valid after the final adjournment thereof. No proxy shall be valid after the
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expiration of eleven (11) months from the date of its execution unless otherwise
provided in the proxy. [T.C.A. 48-706].

                                   ARTICLE II
                               BOARD OF DIRECTORS

         1. Qualification and Election. Directors need not be shareholders or
residents of this state, but must be of legal age. [T.C.A. 48-801.] They shall
be elected by a plurality of the votes cast at the annual meetings of the
shareholders. Each director shall hold office until the expiration of the term
for which he is elected, and thereafter until his successor has been elected and
qualified. [T.C.A. 48-804].

         2. Number. The number of directors shall be fixed from time to time by
the shareholders, or by a majority of the entire Board of Directors, but shall
never be less than the number required by the law. [T.C.A. 48-802.] If there are
less than three (3) shareholders, the number of directors need only match the
number of shareholders. [T.C.A. 48-802(1)(a)]. An increase or decrease in the
number of directors can be accomplished by resolution without having to amend
the By-Laws.

         3. Meetings. The annual meeting of the Board of Directors shall be held
immediate after the adjournment of the annual meeting of the shareholders, at
which time the officers of the corporation shall be elected. [T.C.A. 48-811(2)].
The Board may also designate more frequent intervals for regular meetings.
Special meetings may be called at any time by the chairman of the Board,
president, or any two (2) directors. [T.C.A. 48-808(1)].

         4. Notice of Directors, Meetings. The annual and all regular board
meetings may be held without notice. Special meetings shall be held upon notice
sent by any usual means of communication not less than three (3) days before the
meeting. [T.C.A. 48-808(2)].

         5. Quorum and Vote. The presence of a majority of the directors shall
constitute a quorum for the transaction of business. [T.C.A. 48-102(q)], and
notice of an adjourned meeting need not be given if the time and place to which
the meeting is adjourned are fixed at the meeting at which the adjournment is
taken, and if the period of adjournment does not exceed thirty (30) days in any
adjournment. [T.C.A. 48-808(3)].

         6. Executive and Other Committees. The Board of Directors, by a
resolution adopted by a majority of its members, may designate an executive
committee, consisting of two (2) or more directors, and other committees,
consisting of two (2) or more persons, who may or may not be directors, and may
delegate to such committee or committees any and all such authority as it deems
desirable, including the right to delegate to an executive committee the power
to exercise all the authority of the Board of Directors in the management of the
affairs and property of the corporation. [T.C.A. 48-810].


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                                   ARTICLE III

                                    OFFICERS

         1. Number. The corporation shall have a president and a secretary, and
such other officers as the Board of Directors shall from time to time deem
necessary. Any two (2) or more offices may be held by the same person, except
the offices of president and secretary. [T.C.A. 48- 811(1)].

         2. Election and Term. The officers shall be elected by the Board at its
annual meeting. Each officer shall serve until the expiration of the term for
which he is elected, and thereafter until his successor has been elected and
qualified. The maximum elected term for an officer is two (2) years. [T.C.A.
48-811(2)].

         3. Duties. All officers shall have such authority and perform such
duties in the management of the corporation as are normally incident to their
offices and as the Board of Directors may from time to time provide. [T.C.A.
48-811(3)].

                                   ARTICLE IV
                      RESIGNATIONS, REMOVALS, AND VACANCIES

         1. Resignations. Any officer or director may resign at any time by
giving written notice to the chairman of the Board, the president, or the
secretary. Any such resignation shall take effect at the time specified therein,
or, if no time is specified, then upon its acceptance by the Board of Directors.

         2. Removal of Officers. Any officer or agent may be removed by the
Board whenever in its judgment the best interests of the corporation will be
served thereby. [T.C.A. 48- 811(4)].

         3. Removal of Directors. Any or all of the directors may be removed
either with or without cause by a proper vote of the shareholders; and may be
removed with cause by a majority vote of the entire Board. [T.C.A. 48-807].

         4. Vacancies. Newly created directorships resulting from an increase in
the number of directors, and vacancies occurring in any office or directorship
of any reason, including removal of an officer or director, may be filled by the
vote of a majority of the directors then in office, even if less than a quorum
exists. [T.C.A. 48-806].

                                    ARTICLE V
                                  CAPITAL STOCK

         1. Stock Certificates. Every shareholder shall be entitled to a
certificate or certificates of capital stock of the corporation in such form as
may be prescribed by the Board of Directors. Unless otherwise decided by the
Board, such certificates shall be signed by the president and the secretary of
the corporation. [T.C.A. 48-509].


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         2. Issue and Transfer of Shares. Shares of stock shall be issued only
upon unanimous vote of the directors. Shares of stock may be transferred on the
books of the corporation by delivery and surrender of the properly assigned
certificate, but subject to any restrictions on transfer imposed by either the
applicable security laws or any stockholder agreement.

         3. Loss of Certificates. In the case of the loss, mutilation, or
destruction of a certificate of stock, a duplicate certificate may be issued
upon such terms as the Board shall prescribe.

                                   ARTICLE VI
                                ACTION BY CONSENT

         Whenever the shareholders or directors are required or permitted to
take any action by vote, such action may be taken without a meeting on written
consent, setting forth the action so taken, signed by all the persons or
entities entitled to vote thereon. [T.C.A. 48-1402(1)].

                                   ARTICLE VII
                              AMENDMENT OF BY-LAWS

         These By-Laws may be amended, added to, or repealed either by: (1) a
majority vote of the shares represented at any duly constituted shareholders,
meeting, or (2) a majority vote of the entire Board of Directors. Any change in
the By-Laws made by the Board of Directors, however, may be amended or repealed
by the shareholders. [T.C.A. 48-812].

                                  CERTIFICATION

         I certify that these By-Laws were duly adopted by the incorporator at
the organization meeting of the corporation and adopted, ratified and approved
at the first meeting of shareholders, and are the By-Laws in effect this 1st day
of July, 1986.

                                           /s/ John Minchey
                                           -------------------------------------
                                           JOHN MINCHEY, SECRETARY



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