<PAGE>
                                                                     EXHIBIT 4.3


                          SECOND AMENDED AND RESTATED
                                     BYLAWS
                                       OF
                                  AMSURG CORP.
                               (THE "CORPORATION")


                                   ARTICLE I.

                                     OFFICES

         The Corporation may have such offices, either within or without the
State of Tennessee, as the Board of Directors may designate or as the business
of the Corporation may require from time to time.

                                   ARTICLE II.

                                  SHAREHOLDERS

         2.1      ANNUAL MEETING.

         An annual meeting of the shareholders of the Corporation shall be held
on such date as may be determined by the Board of Directors. The business to be
transacted at such meeting shall be the election of directors and such other
business as shall be properly brought before the meeting.

         2.2      SPECIAL MEETINGS.

         A special meeting of shareholders shall be held on call of the Board of
Directors or if the holders of at least fifteen percent (15%) of the voting
power of the Common Stock sign, date, and deliver to the Corporation's Secretary
one (1) or more written demands for the meeting describing the purpose or
purposes for which such special meeting is to be held, including all statements
necessary to make any statement of such purpose not incomplete, false or
misleading, and include any other information specified in Schedule 14A, Rule
14a-3, Rule 14a-8, or Rule 14a-11 of the Rules and Regulations of the Securities
and Exchange Commission. Only business within the



<PAGE>



purpose or purposes described in the meeting notice may be conducted at a
special shareholders' meeting.

         2.3      PLACE OF MEETINGS.

         The Board of Directors may designate any place, either within or
without the State of Tennessee, as the place of meeting for any annual meeting
or for any special meeting. If no place is fixed by the Board of Directors, the
meeting shall be held at the principal office of the Corporation.

         2.4      NOTICE OF MEETINGS; WAIVER.

                  (a) NOTICE. Notice of the date, time and place of each annual
and special shareholders' meeting and, in the case of a special meeting, a
description of the purpose or purposes for which the meeting is called, shall be
given no fewer than ten (10) days nor more than two (2) months before the date
of the meeting. Such notice shall comply with the requirements of Article XI of
these Bylaws.

                  (b) WAIVER. A shareholder may waive any notice required by
law, the Corporation's Amended and Restated Charter (the "Charter") or these
Bylaws before or after the date and time stated in such notice. Except as
provided in the next sentence, the waiver must be in writing, be signed by the
shareholder entitled to the notice and be delivered to the Corporation for
inclusion in the minutes or filing with the corporate records. A shareholder's
attendance at a meeting: (1) waives objection to lack of notice or defective
notice of the meeting, unless the shareholder at the beginning of the meeting
(or promptly upon his arrival) objects to holding the meeting or transacting
business at the meeting; and (2) waives objection to consideration of a
particular matter at the meeting that is not within the purpose or purposes
described in the meeting notice, unless the shareholder objects to considering
the matter when it is presented.

                                        2


<PAGE>



         2.5      RECORD DATE.

         The Board of Directors shall fix as the record date for the
determination of shareholders entitled to notice of a shareholders' meeting, to
demand a special meeting, to vote, or to take any other action, a date not more
than seventy (70) days before the meeting or action requiring a determination of
shareholders.

         A record date fixed for a shareholders' meeting is effective for any
adjournment of such meeting unless the Board of Directors fixes a new record
date, which it must do if the meeting is adjourned to a date more than four (4)
months after the date fixed for the original meeting.

         2.6      SHAREHOLDERS' LIST.

         After the record date for a meeting has been fixed, the Corporation
shall prepare an alphabetical list of the names of all shareholders who are
entitled to notice of a shareholders' meeting. Such list will show the address
of and number of shares held by each shareholder. The shareholders' list will be
available for inspection by any shareholder, beginning two (2) business days
after notice of the meeting is given for which the list was prepared and
continuing through the meeting, at the Corporation's principal office or at a
place identified in the meeting notice in the city where the meeting will be
held. A shareholder or his agent or attorney is entitled on written demand to
inspect and, subject to the requirements of the Tennessee Business Corporation
Act (the "Act"), to copy the list, during regular business hours and at his
expense, during the period it is available for inspection.

         2.7      VOTING GROUPS; QUORUM; ADJOURNMENT.

         All shares entitled to vote and be counted together collectively on a
matter at a meeting of shareholders shall be a "voting group". Shares entitled
to vote as a separate voting group may take action on a matter at a meeting only
if a quorum of those shares exists with respect to that matter.

                                        3


<PAGE>



Except as otherwise required by the Act or provided in the Charter, a majority
of the votes entitled to be cast on a matter by a voting group constitutes a
quorum of that voting group for action on that matter.

         Once a share is represented for any purpose at a meeting, it is deemed
present for quorum purposes for the remainder of the meeting and for any
adjournment of that meeting unless a new record date is or must be set for that
adjourned meeting.

         If a quorum of a voting group shall not be present or represented at
any meeting, the shares entitled to vote thereat shall have power to adjourn the
meeting to a different date, time or place without notice other than
announcement at the meeting of the new time, date or place to which the meeting
is adjourned. At any adjourned meeting at which a quorum of any voting group
shall be present or represented, any business may be transacted by such voting
group which might have been transacted at the meeting as originally called.

         2.8      VOTING OF SHARES.

         Unless otherwise provided by the Act or the Charter, each outstanding
share is entitled to one (1) vote on each matter voted on at a shareholders'
meeting. Only shares are entitled to vote. If a quorum exists, approval of
action on a matter (other than the election of directors) by a voting group
entitled to vote thereon is received if the votes cast within the voting group
favoring the action exceed the votes cast opposing the action, unless the
Charter or the Act requires a greater number of affirmative votes. Unless
otherwise provided in the Charter, directors are elected by a plurality of the
votes cast by the shares entitled to vote in the election at a meeting at which
a quorum is present.

                                        4


<PAGE>



         2.9      PROXIES.

         A shareholder may vote his or her shares in person or by proxy. A
shareholder may appoint a proxy to vote or otherwise act for him or her by
signing an appointment either personally or through an attorney-in-fact. An
appointment of a proxy is effective when received by the Secretary or other
officer or agent authorized to tabulate votes. An appointment is valid for
eleven (11) months unless another period is expressly provided in the
appointment form. An appointment of a proxy is revocable by the shareholder
unless the appointment form conspicuously states that it is irrevocable and the
appointment is coupled with an interest.

         2.10     ACCEPTANCE OF SHAREHOLDER DOCUMENTS.

         If the name signed on a shareholder document (a vote, consent, waiver,
or proxy appointment) corresponds to the name of a shareholder, the Corporation,
if acting in good faith, is entitled to accept such shareholder document and
give it effect as the act of the shareholder. If the name signed on such
shareholder document does not correspond to the name of a shareholder, the
Corporation, if acting in good faith, is nevertheless entitled to accept such
shareholder document and to give it effect as the act of the shareholder if:

                  (i) the shareholder is an entity and the name signed purports
         to be that of an officer or agent of the entity;

                  (ii) the name signed purports to be that of a fiduciary
         representing the shareholder and, if the Corporation requests, evidence
         of fiduciary status acceptable to the Corporation has been presented
         with respect to such shareholder document;

                  (iii) the name signed purports to be that of a receiver or
         trustee in bankruptcy of the shareholder and, if the Corporation
         requests, evidence of this status acceptable to the Corporation has
         been presented with respect to the shareholder document;

                                        5


<PAGE>



                  (iv) the name signed purports to be that of a pledgee,
         beneficial owner, or attorney-in-fact of the shareholder and, if the
         Corporation requests, evidence acceptable to the Corporation of the
         signatory's authority to sign for the shareholder has been presented
         with respect to such shareholder document; or

                  (v) two or more persons are the shareholder as co-tenants or
         fiduciaries and the name signed purports to be the name of at least one
         (1) of the co-owners and the person signing appears to be acting on
         behalf of all the co-owners.

         The Corporation is entitled to reject a shareholder document if the
Secretary or other officer or agent authorized to tabulate votes, acting in good
faith, has a reasonable basis for doubt about the validity of the signature on
such shareholder document or about the signatory's authority to sign for the
shareholder.

         2.11     ACTION WITHOUT MEETING.

         Action required or permitted by the Act to be taken at a shareholders'
meeting may be taken without a meeting. If all shareholders entitled to vote on
the action consent to taking such action without a meeting, the affirmative vote
of the number of shares that would be necessary to authorize or take such action
at a meeting is the act of the shareholders.

         The action must be evidenced by one (1) or more written consents
describing the action taken, at least one of which is signed by each shareholder
entitled to vote on the action in one (1) or more counterparts, indicating such
signing shareholder's vote or abstention on the action and delivered to the
Corporation for inclusion in the minutes or for filing with the corporate
records.

         If the Act or the Charter requires that notice of a proposed action be
given to nonvoting shareholders and the action is to be taken by consent of the
voting shareholders, then the Corporation shall give its nonvoting shareholders
written notice of the proposed action at least ten (10) days

                                        6


<PAGE>



before such action is taken. Such notice shall contain or be accompanied by the
same material that would have been required to be sent to nonvoting shareholders
in a notice of a meeting at which the proposed action would have been submitted
to the shareholders for action.

         2.12     PRESIDING OFFICER AND SECRETARY.

         Meetings of the shareholders shall be presided over by the Chairman of
the Board (the "Chairman"), or if the Chairman is not present or if the
Corporation shall not have a Chairman, by the President or Chief Executive
Officer, or if neither the Chairman nor the President or Chief Executive Officer
is present, by a chairman chosen by a majority of the shareholders entitled to
vote at such meeting. The Secretary or, in the Secretary's absence, an Assistant
Secretary shall act as secretary of every meeting, but if neither the Secretary
nor an Assistant Secretary is present, a majority of the shareholders entitled
to vote at such meeting shall choose any person present to act as secretary of
the meeting.

         2.13     NOTICE OF NOMINATIONS.

         Nominations for the election of directors may be made by the Board of
Directors or a committee appointed by the Board of Directors authorized to make
such nominations or by any shareholder entitled to vote in the election of
directors generally. However, any such shareholder nomination may be made only
if written notice of such nomination has been given, either by personal delivery
or the United States mail, postage prepaid, to the Secretary of the Corporation
not later than (a) with respect to an election to be held at an annual meeting
of shareholders, one hundred twenty (120) days in advance of the anniversary
date of the proxy statement for the previous year's annual meeting, and (b) with
respect to an election to be held at a special meeting of shareholders for the
election of directors called other than by written request of a shareholder, the
close of business on the tenth day following the date on which notice of such
meeting is first given to

                                        7


<PAGE>



shareholders, and (c) in the case of a special meeting of shareholders duly
called upon the written request of a shareholder to fill a vacancy or vacancies
(then existing or proposed to be created by removal at such meeting), within ten
(10) business days of such written request. In the case of any nomination by the
Board of Directors or a committee appointed by the Board of Directors authorized
to make such nominations, compliance with the proxy rules of the Securities and
Exchange Commission shall constitute compliance with the notice provisions of
the preceding sentence.

         In the case of any nomination by a shareholder, each such notice shall
set forth: (a) as to each person whom the shareholder proposes to nominate for
election or re-election as a director, (i) the name, age, business address, and
residence address of such person, (ii) the principal occupation or employment of
such person, (iii) the class and number of shares of the Corporation which are
beneficially owned by such person, and (iv) any other information relating to
such person that is required to be disclosed in solicitations of proxies with
respect to nominees for election as directors, pursuant to Regulation 14A under
the Securities Exchange Act of 1934, as amended (including without limitation
such person's written consent to being named in the proxy statement as a nominee
and to serving as a director, if elected); and (b) as to the shareholder giving
the notice (i) the name and address, as they appear on the Corporation's books,
of such shareholder, and (ii) the class and number of shares of the Corporation
which are beneficially owned by such shareholder; and (c) a description of all
arrangements or understandings between the shareholder and each nominee and any
other person or persons (naming such person or persons) pursuant to which the
nomination or nominations are to be made by the shareholder. The President,
Chief Executive Officer, or chairman of the meeting may refuse to acknowledge
the nomination of any person not made in compliance with the foregoing
procedure.

         2.14     NOTICE OF NEW BUSINESS.

                                        8


<PAGE>



         At an annual meeting of the shareholders only such new business shall
be conducted, and only such proposals shall be acted upon, as have been properly
brought before the meeting. To be properly brought before the annual meeting
such new business must be (a) specified in the notice of meeting (or any
supplement thereto) given by or at the direction of the Board of Directors, (b)
otherwise properly brought before the meeting by or at the direction of the
Board of Directors, or (c) otherwise properly brought before the meeting by a
shareholder. For a proposal to be properly brought before an annual meeting by a
shareholder, the shareholder must have given timely notice thereof in writing to
the Secretary of the Corporation and the proposal and the shareholder must
comply with Rule 14a-8 under the Securities Exchange Act of 1934. To be timely,
a shareholder's notice must be delivered to or mailed and received at the
principal executive offices of the Corporation within the time limits specified
by Rule 14a-8.

         A shareholder's notice to the Secretary shall set forth as to each
matter the shareholder proposes to bring before the annual meeting (a) a brief
description of the proposal desired to be brought before the annual meeting and
the reasons for conducting such business at the annual meeting, (b) the name and
address, as they appear on the Corporation's books, of the shareholder proposing
such business, (c) the class and number of shares of the Corporation which are
beneficially owned by the shareholder, and (d) any financial interest of the
shareholder in such proposal.

         Notwithstanding anything in these Bylaws to the contrary, no business
shall be conducted at an annual meeting except in accordance with the procedures
set forth in this Section 2.14. The President, Chief Executive Officer, or
chairman of the meeting shall, if the facts warrant, determine and declare to
the meeting that new business or any shareholder proposal was not properly
brought before the meeting in accordance with the provisions of this Section
2.14, and if he or she should

                                        9


<PAGE>



so determine, he or she shall so declare to the meeting and any such business or
proposal not properly brought before the meeting shall not be acted upon at the
meeting. This provision shall not prevent the consideration and approval or
disapproval at the annual meeting of reports of officers, directors and
committees, but in connection with such reports no new business shall be acted
upon at such annual meeting unless stated and filed as herein provided.

         2.15     CONDUCT OF MEETINGS.

         Meetings of the shareholders generally shall follow accepted rules of
parliamentary procedure subject to the following:

         (a) The President, Chief Executive Officer, or chairman of the meeting
shall have absolute authority over the matters of procedure, and there shall be
no appeal from the ruling of the President, Chief Executive Officer, or
chairman. If, in his or her absolute discretion, the President, Chief Executive
Officer, or chairman deems it advisable to dispense with the rules of
parliamentary procedure as to any meeting of shareholders or part thereof, he or
she shall so state and shall state the rules under which the meeting or
appropriate part thereof shall be conducted.

         (b) If disorder should arise which prevents the continuation of the
legitimate business of the meeting, the President, Chief Executive Officer, or
chairman may quit the chair and announce the adjournment of the meeting, and
upon so doing, the meeting will immediately be adjourned.

         (c) The President, Chief Executive Officer, or chairman may ask or
require that anyone not a bona fide shareholder or proxy leave the meeting.

         (d) The resolution or motion shall be considered for vote only if
proposed by a shareholder or a duly authorized proxy and seconded by a
shareholder or duly authorized proxy other than the individual who proposed the
resolution or motion.

                                       10


<PAGE>



         (e) Except as the President, Chief Executive Officer, or chairman may
permit, no matter shall be presented to the meeting which has not been submitted
for inclusion in the agenda at least thirty (30) days prior to the meeting.

                                  ARTICLE III.

                                    DIRECTORS

         3.1      POWERS AND DUTIES.

         All corporate powers shall be exercised by or under the authority of
and the business and affairs of the Corporation managed under the direction of
the Board of Directors.

         3.2      NUMBER AND TERM.

                  (a) NUMBER. The Board of Directors shall consist of no fewer
than three (3) or more than twelve (12) members. The exact number of directors,
within the minimum and maximum, or the range for the size of the Board, or
whether the size of the Board shall be fixed or variable-range may be fixed,
changed or determined from time to time by the Board of Directors.

                  (b) TERM. The Board of Directors shall be divided into three
classes, designated Class I, Class II and Class III. Each class shall consist,
as nearly as possible, of one-third of the total number of directors
constituting the entire Board of Directors. Each class of directors shall be
elected for a three-year term, except at the 1997 annual meeting of
shareholders, Class I directors shall be elected for a one-year term; Class II
directors shall be elected for a two-year term; and Class III directors shall be
elected for a three-year term. If the number of directors is changed, any
increase or decrease shall be apportioned among the classes so as to maintain
the number of directors in each class as nearly equal as possible, and any
additional director of any class elected to fill a vacancy resulting from an
increase in such class shall hold office for a term that shall coincide with

                                       11


<PAGE>



the remaining term of that class, but in no case will a decrease in the number
of directors shorten the term of any incumbent director. A director shall hold
office until the annual meeting for the year in which his or her term expires
and until his or her successor shall be elected and shall qualify, subject,
however, to prior death, resignation, retirement, disqualification or removal
from office.

         3.3      MEETINGS; NOTICE.

         The Board of Directors may hold regular and special meetings either
within or without the State of Tennessee. The Board of Directors may permit any
or all directors to participate in a regular or special meeting by, or conduct
the meeting through the use of, any means of communication by which all
directors participating may simultaneously hear each other during the meeting. A
director participating in a meeting by this means is deemed to be present in
person at the meeting.

                  (a)      REGULAR MEETINGS.  Unless the Charter otherwise
provides, regular meetings of the Board of Directors may be held without notice
of the date, time, place, or purpose of the meeting.

                  (b)      SPECIAL MEETINGS. Special meetings of the Board of
Directors may be called by the Chairman, the President, Chief Executive Officer,
or one-third of the entire Board of Directors. Unless the Charter otherwise
provides, special meetings must be preceded by at least twenty-four (24) hours'
notice of the date, time, and place of the meeting but need not describe the
purpose of such meeting. Such notice shall comply with the requirements of
Article XI of these Bylaws.

                  (c)      ADJOURNED MEETINGS. 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

                                       12


<PAGE>



adjournment is taken, and if the period of adjournment does not exceed one (1)
month in any one (1) adjournment.

                  (d) WAIVER OF NOTICE. A director may waive any required notice
before or after the date and time stated in the notice. Except as provided in
the next sentence, the waiver must be in writing, signed by the director, and
filed with the minutes or corporate records. A director's attendance at or
participation in a meeting waives any required notice to him or her of such
meeting unless the director at the beginning of the meeting (or promptly upon
his arrival) objects to holding the meeting or transacting business at the
meeting and does not thereafter vote for or assent to action taken at the
meeting.

         3.4      QUORUM.

         Unless the Charter requires a greater number, a quorum of the Board of
Directors consists of a majority of the fixed number of directors if the
Corporation has a fixed board size or a majority of the number of directors
prescribed, or if no number is prescribed, the number in office immediately
before the meeting begins, if the Corporation has a variable range board.

         3.5      VOTING.

         If a quorum is present when a vote is taken, the affirmative vote of a
majority of directors present is the act of the Board of Directors, unless the
Charter or these Bylaws require the vote of a greater number of directors. A
director who is present at a meeting of the Board of Directors when corporate
action is taken is deemed to have assented to such action unless:

                  (i) he or she objects at the beginning of the meeting (or
         promptly upon his or her arrival) to holding the meeting or transacting
         business at the meeting;

                  (ii) his or her dissent or abstention from the action taken is
         entered in the minutes of the meeting; or

                                       13


<PAGE>



                  (iii) he or she delivers written notice of his or her dissent
         or abstention to the presiding officer of the meeting before its
         adjournment or to the Corporation immediately after adjournment of the
         meeting. The right of dissent or abstention is not available to a
         director who votes in favor of the action taken.

         3.6      ACTION WITHOUT MEETING.

         Unless the Charter otherwise provides, any action required or permitted
by the Act to be taken at a Board of Directors meeting may be taken without a
meeting. If all directors consent to taking such action without a meeting, the
affirmative vote of the number of directors that would be necessary to authorize
or take such action at a meeting is the act of the Board of Directors. Such
action must be evidenced by one or more written consents describing the action
taken, at least one of which is signed by each director, indicating the
director's vote or abstention on the action, which consents shall be included in
the minutes or filed with the corporate records reflecting the action taken.
Action taken by consent is effective when the last director signs the consent,
unless the consent specifies a different effective date.

         3.7      COMPENSATION.

         Directors and members of any committee created by the Board of
Directors shall be entitled to such reasonable compensation for their services
as directors and members of such committee as shall be fixed from time to time
by the Board, and shall also be entitled to reimbursement for any reasonable
expenses incurred in attending meetings of the Board or of any such committee
meetings. Any director receiving such compensation shall not be barred from
serving the Corporation in any other capacity and receiving reasonable
compensation for such other services.

         3.8      RESIGNATION.

                                       14


<PAGE>



         A director may resign at any time by delivering written notice to the
Board of Directors, the Chairman, President, or Chief Executive Officer, or to
the Corporation. A resignation is effective when the notice is delivered unless
the notice specifies a later effective date.

         3.9      VACANCIES.

         Unless the Charter otherwise provides, if a vacancy occurs on the Board
of Directors, including a vacancy resulting from an increase in the number of
directors or a vacancy resulting from the removal of a director with or without
cause, either the shareholders or the Board of Directors may fill such vacancy.
If the vacancy is filled by the shareholders, it shall be filled by a plurality
of the votes cast at a meeting at which a quorum is present. If the directors
remaining in office constitute fewer than a quorum of the Board of Directors,
they may fill such vacancy by the affirmative vote of a majority of all the
directors remaining in office. If the vacant office was held by a director
elected by a voting group of shareholders, only the holders of shares of that
voting group shall be entitled to vote to fill the vacancy if it is filled by
the shareholders.

         3.10     REMOVAL OF DIRECTORS.

                  (a) BY SHAREHOLDERS. The shareholders may remove one (1) or
more directors solely for cause as defined in the Charter. If cumulative voting
is authorized, a director may not be removed for cause if the number of votes
sufficient to elect him or her under cumulative voting is voted against his or
her removal. If cumulative voting is not authorized, a director may be removed
for cause only if the number of votes cast to remove him or her exceeds the
number of votes cast not to remove him or her.

                  (b) GENERAL. A director may be removed for cause by the
shareholders only at a meeting called for the purpose of removing him or her,
and the meeting notice must state that the purpose, or one (1) of the purposes,
of the meeting is removal of directors for cause.

                                       15


<PAGE>



         3.11     ELECTRONIC COMMUNICATION.

         Any one or more members of the Board of Directors or any committee
thereof may participate in a meeting of the Board of Directors or any such
committee by means of a conference telephone or similar communications equipment
allowing all persons participating in the meeting to hear each other at the same
time. Participation by such means shall constitute presence in person at a
meeting.

         3.12     CHAIRMAN OF THE BOARD.

         The Chairman of the Board shall be appointed from time to time by the
Board of Directors and shall preside at all meetings of the Board of Directors
and of the shareholders of the Corporation.

                                   ARTICLE IV.

                                   COMMITTEES

         Unless the Charter otherwise provides, the Board of Directors may
create one (1) or more committees, each consisting of one (1) or more members.
All members of committees of the Board of Directors which exercise powers of the
Board of Directors must be members of the Board of Directors and serve at the
pleasure of the Board of Directors.

         The creation of a committee and appointment of a member or members to
it must be approved by the greater of (i) a majority of all directors in office
when the action is taken or (ii) the number of directors required by the Charter
or these Bylaws to take action.

         Unless otherwise provided in the Act, to the extent specified by the
Board of Directors or in the Charter, each committee may exercise the authority
of the Board of Directors. All such committees and their members shall be
governed by the same statutory requirements regarding

                                       16


<PAGE>



meetings, action without meetings, notice and waiver of notice, quorum, and
voting requirements as are applicable to the Board of Directors and its members.

                                   ARTICLE V.

                                    OFFICERS

         5.1      NUMBER.

         The officers of the Corporation shall be a President, a Chief Executive
Officer, a Chief Financial Officer, a Secretary and such other officers as may
be from time to time appointed by the Board of Directors or by the Chairman or
Chief Executive Officer with the Board of Directors' approval. The Chairman may,
but need not be, an officer of the Corporation. One person may simultaneously
hold more than one office, except the President may not simultaneously hold the
office of Secretary.

         5.2      APPOINTMENT.

         The principal officers shall be appointed annually by the Board of
Directors at the first meeting of the Board following the annual meeting of the
shareholders, or as soon thereafter as is conveniently possible. Each officer
shall serve at the pleasure of the Board of Directors and until his or her
successor shall have been appointed, or until his or her death, resignation, or
removal.

         5.3      RESIGNATION AND REMOVAL.

         An officer may resign at any time by delivering notice to the
Corporation. Such resignation is effective when such notice is delivered unless
such notice specifies a later effective date. An officer's resignation does not
affect the Corporation's contract rights, if any, with the officer.

         The Board of Directors may remove any officer at any time with or
without cause, but such removal shall not prejudice the contract rights, if any,
of the person so removed.

                                       17


<PAGE>



         5.4      VACANCIES.

         Any vacancy in an office for any reason may be filled for the unexpired
portion of the term by the Board of Directors.

         5.5      DUTIES.

                  (a) CHAIRMAN. The Chairman shall preside at all meetings of
the shareholders and the Board of Directors.

                  (b) CHIEF EXECUTIVE OFFICER. The Chief Executive Officer of
the Corporation shall have general supervision over the active management of the
business of the Corporation and shall see that all orders and resolutions of the
Board of Directors are carried into effect.

                  (c) PRESIDENT. The President shall have the general powers and
duties of supervision and management usually vested in the office of the
President of a corporation and shall perform such other duties as the Board of
Directors may from time to time prescribe.

                  (d) CHIEF FINANCIAL OFFICER. The Chief Financial Officer
shall, subject to the power of the President and the Chief Executive Officer,
have general and active control of all of the financial matters of the
Corporation and shall have all necessary powers to discharge such responsibility
and shall perform such other duties as the Board of Directors, the President,
the Chief Executive Officer or the Chairman may prescribe.

                  (e) VICE PRESIDENT. The Vice President or Vice Presidents (if
any) shall be active executive officers of the Corporation, shall assist the
Chairman, President, and Chief Executive Officer in the active management of the
business, and shall perform such other duties as the Board of Directors may from
time to time prescribe.

                  (f) SECRETARY AND ASSISTANT SECRETARY. The Secretary or
Assistant Secretary shall attend all meetings of the Board of Directors and all
meetings of the shareholders and shall

                                       18


<PAGE>



prepare and record all votes and all minutes of all such meetings in a book to
be kept for that purpose. He or she shall also perform like duties for any
committee when required. The Secretary or Assistant Secretary shall give, or
cause to be given, notice of all meetings of the shareholders and of the Board
of Directors when required, and unless directed otherwise by the Board of
Directors, shall keep a stock record containing the names of all persons who are
shareholders of the Corporation, showing their place of residence and the
number of shares held by each of them. The Secretary or Assistant Secretary
shall have the responsibility of authenticating records of the Corporation. The
Secretary or Assistant Secretary shall perform such other duties as may be
prescribed from time to time by the Board of Directors.

                  (g) OTHER OFFICERS. Other officers appointed by the Board of
Directors shall exercise such powers and perform such duties as may be delegated
to them.

                  (h) DELEGATION OF DUTIES. In case of the absence or disability
of any officer of the Corporation or of any person authorized to act in his or
her place, the Board of Directors may from time to time delegate the powers and
duties of such officer to any officer, or any director, or any other person whom
it may select, during such period of absence or disability.

         5.6      INDEMNIFICATION, ADVANCEMENT OF EXPENSES, AND INSURANCE.

                  (a) INDEMNIFICATION AND ADVANCEMENT OF EXPENSES. The
Corporation shall indemnify and advance expenses to each director, officer and
medical director of the Corporation, or any person who may have served at the
request of the Corporation's Board of Directors or its President or Chief
Executive Officer as a director or officer of another corporation (and, in
either case, such person's heirs, executors, and administrators), to the full
extent allowed by the laws of the State of Tennessee, both as now in effect and
as hereafter adopted. The Corporation may indemnify and advance expenses to any
employee or agent of the Corporation who is not a director

                                       19


<PAGE>



or officer (and such person's heirs, executors, and administrators) to the same
extent as to a director or officer, if the Board of Directors determines that
doing so is in the best interests of the Corporation.

                  (b) NON-EXCLUSIVITY OF RIGHTS. The indemnification and expense
advancement provisions of subsection (a) of this Section 5.6 shall not be
exclusive of any other right which any person (and such person's heirs,
executors and administrators) may have or hereafter acquire under any statute,
provision of the Charter, provision of these Bylaws, resolution adopted by the
shareholders, resolution adopted by the Board of Directors, agreement, or
insurance (purchased by the Corporation or otherwise), both as to action in such
person's official capacity and as to action in another capacity.

                  (c) INSURANCE. The Corporation may maintain insurance, at its
expense, to protect itself and any individual who is or was a director, officer,
employee, or agent of the Corporation, or who, while a director, officer,
employee, or agent of the Corporation, is or was serving at the request of the
Corporation's Board of Directors or its Chief Executive Officer as a director,
officer, partner, trustee, employee, or agent of another corporation,
partnership, joint venture, trust, employee benefit plan, or other enterprise
against any expense, liability, or loss, whether or not the Corporation would
have the power to indemnify such person against such expense, liability, or loss
under this Article or the Act.

                                       20


<PAGE>



                                   ARTICLE VI.

                                 SHARES OF STOCK

         6.1      SHARES WITH OR WITHOUT CERTIFICATES.

         The Board of Directors may authorize that some or all of the shares of
any or all of the Corporation's classes or series of stock be evidenced by a
certificate or certificates of stock. The Board of Directors may also authorize
the issue of some or all of the shares of any or all of the Corporation's
classes or series of stock without certificates. The rights and obligations of
shareholders with the same class and/or series of stock shall be identical
whether or not their shares are represented by certificates.

                  (a) SHARES WITH CERTIFICATES. If the Board of Directors
chooses to issue shares of stock evidenced by a certificate or certificates,
each individual certificate shall include the following on its face: (i) the
Corporation's name, (ii) the fact that the Corporation is organized under the
laws of the State of Tennessee, (iii) the name of the person to whom the
certificate is issued, (iv) the number of shares represented thereby, (v) the
class of shares and the designation of the series, if any, which the certificate
represents, and (vi) such other information as applicable law may require or as
may be lawful.

                  If the Corporation is authorized to issue different classes of
shares or different series within a class, the designations, relative rights,
preferences, and limitations determined for each series (and the authority of
the Board of Directors to determine variations for future series) shall be
summarized on the front or back of each certificate. Alternatively, each
certificate shall state on its front or back that the Corporation will furnish
the shareholder this information in writing, without charge, upon request.

                                       21


<PAGE>



                  Each certificate of stock issued by the Corporation shall be
signed (either manually or in facsimile) by any two officers of the Corporation.
If the person who signed a certificate no longer holds office when the
certificate is issued, the certificate is nonetheless valid.

                  (b) SHARES WITHOUT CERTIFICATES. If the Board of Directors
chooses to issue shares of stock without certificates, the Corporation, if
required by the Act, shall, within a reasonable time after the issue or
transfer of shares without certificates, send the shareholder a written
statement of the information required on certificates by Section 6.1(a) of these
Bylaws and any other information required by the Act.

         6.2      SUBSCRIPTIONS FOR SHARES.

         Subscriptions for shares of the Corporation shall be valid only if they
are in writing. Unless the subscription agreement provides otherwise,
subscriptions for shares, regardless of the time when they are made, shall be
paid in full at such time, or in such installments and at such periods, as shall
be determined by the Board of Directors. All calls for payment on subscriptions
shall be uniform as to all shares of the same class or of the same series,
unless the subscription agreement specifies otherwise.

         6.3      TRANSFERS.

         Transfers of shares of the capital stock of the Corporation shall be
made only on the books of the Corporation by (i) the holder of record thereof,
(ii) his or her legal representative, who, upon request of the Corporation,
shall furnish proper evidence of authority to transfer, or (iii) his or her
attorney, authorized by a power of attorney duly executed and filed with the
Secretary of the Corporation or a duly appointed transfer agent. Such transfers
shall be made only upon surrender, if applicable, of the certificate or
certificates for such shares properly endorsed and with all taxes thereon paid.

                                       22


<PAGE>



         6.4      LOST, DESTROYED, OR STOLEN CERTIFICATES.

         No certificate for shares of stock of the Corporation shall be issued
in place of any certificate alleged to have been lost, destroyed, or stolen
except on production of evidence, satisfactory to the Board of Directors, of
such loss, destruction, or theft, and, if the Board of Directors so requires,
upon the furnishing of an indemnity bond in such amount and with such terms and
such surety as the Board of Directors may in its discretion require.

                                  ARTICLE VII.

                                CORPORATE ACTIONS

         7.1      CONTRACTS.

         Unless otherwise required by the Board of Directors, the Chairman, the
President, the Chief Executive Officer, or any Vice President shall execute
contracts or other instruments on behalf of and in the name of the Corporation.
The Board of Directors may from time to time authorize any other officer,
assistant officer, or agent to enter into any contract or execute any instrument
in the name of and on behalf of the Corporation as it may deem appropriate, and
such authority may be general or confined to specific instances.

         7.2      LOANS.

         No loans shall be contracted on behalf of the Corporation and no
evidence of indebtedness shall be issued in its name unless authorized by the
Chairman, the President, the Chief Executive Officer, or the Board of Directors.
Such authority may be general or confined to specific instances.

                                       23


<PAGE>



         7.3      CHECKS, DRAFTS, ETC.

         Unless otherwise required by the Board of Directors, all checks,
drafts, bills of exchange, and other negotiable instruments of the Corporation
shall be signed by either the Chairman, the President, the Chief Executive
Officer, a Vice President or such other officer, assistant officer, or agent of
the Corporation as may be authorized so to do by the Board of Directors. Such
authority may be general or confined to specific business, and, if so directed
by the Board, the signatures of two or more such officers may be required.

         7.4      DEPOSITS.

         All funds of the Company not otherwise employed shall be deposited from
time to time to the credit of the Corporation in such banks or other
depositories as the Board of Directors may authorize.

         7.5      VOTING SECURITIES HELD BY THE CORPORATION.

         Unless otherwise required by the Board of Directors, the Chairman,
President, or Chief Executive officer shall have full power and authority on
behalf of the Corporation to attend any meeting of security holders, or to take
action on written consent as a security holder, of other corporations in which
the Corporation may hold securities. In connection therewith the Chairman, the
President, or the Chief Executive Officer shall possess and may exercise any and
all rights and powers incident to the ownership of such securities which the
Corporation possesses. The Board of Directors may, from time to time, confer
like powers upon any other person or persons.

                                       24


<PAGE>



         7.6      DIVIDENDS.

         The Board of Directors may, from time to time, declare, and the
Corporation may pay, dividends on its outstanding shares of capital stock in the
manner and upon the terms and conditions provided by applicable law. The record
date for the determination of shareholders entitled to receive the payment of
any dividend shall be determined by the Board of Directors, but which in any
event shall not be less than ten (10) days prior to the date of such payment.

                                  ARTICLE VIII.

                                   FISCAL YEAR

         The fiscal year of the Corporation shall be determined by the Board of
Directors, and in the absence of such determination, shall be the calendar year.

                                   ARTICLE IX.

                                 CORPORATE SEAL

         The Corporation shall not have a corporate seal.

                                   ARTICLE X.

                               AMENDMENT OF BYLAWS

         These Bylaws may be altered, amended, repealed, or restated, and new
Bylaws may be adopted, at any meeting of the shareholders by the affirmative
vote of a majority of the stock represented at such meeting, or by the
affirmative vote of a majority of the members of the Board of Directors who are
present at any regular or special meeting.

                                       25


<PAGE>



                                   ARTICLE XI.

                                     NOTICE

         Unless otherwise provided for in these Bylaws, any notice required
shall be in writing except that oral notice is effective if it is reasonable
under the circumstances and not prohibited by the Charter or these Bylaws.
Notice may be communicated in person, by telephone, telegraph, teletype or other
form of wire or wireless communication, or by mail or private carrier. If these
forms of personal notice are impracticable, notice may be communicated by a
newspaper of general circulation in the area where published, or by radio,
television, or other form of public broadcast communication. Written notice to a
domestic or foreign corporation authorized to transact business in Tennessee may
be addressed to its registered agent at its registered office or to the
corporation or its secretary at its principal office as shown in its most recent
annual report or, in the case of a foreign corporation that has not yet
delivered an annual report, in its application for a certificate of authority.

         Written notice to shareholders, if in a comprehensible form, is
effective when mailed, if mailed postpaid and correctly addressed to the
shareholder's address shown in the Corporation's current record of shareholders.
Except as provided above, written notice, if in a comprehensible form, is
effective at the earliest of the following: (a) when received; (b) five (5) days
after its deposit in the United States mail, if mailed correctly addressed and
with first class postage affixed thereon; (c) on the date shown on the return
receipt, if sent by registered or certified mail, return receipt requested, and
the receipt is signed by or on behalf of the addressee; or (d) twenty (20) days
after its deposit in the United States mail, as evidenced by the postmark if
mailed correctly addressed, and with other than first class, registered, or
certified postage affixed. Oral notice is effective when communicated if
communicated in a comprehensible manner.

                                       26