Sample Code to get List Schema via Object Model.

SPSecurity.RunWithElevatedPrivileges(delegate()
                {
                    using (SPWeb oWebsite = SPContext.Current.Web)
                    {
                        SPList oList = oWebsite.Lists["Tasks"];

                        SPQuery oQuery = new SPQuery();
                        oQuery.Query = "<OrderBy><FieldRef Name='ID'
Ascending='False' /></OrderBy>";
                        oQuery.ViewFields = "<FieldRef Name='Title'/

><FieldRef Name='Status'/><FieldRef Name='Priority'/><FieldRef

Name='AssignedTo'/>";
                        SPListItemCollection colListItemsAvailable =
                          oList.GetItems(oQuery);
                        foreach (SPListItem oListItemAvailable in
colListItemsAvailable)
                        {

writer.Write(Microsoft.SharePoint.Utilities.SPEncode.HtmlEncode(oListItemAvailable.Xml)
+
                              "<BR>");
                        }
                    }
                });

Here is the output of list schema
<z:row xmlns:z='#RowsetSchema' ows_Title='Task012' ows_Status='In
Progress' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='12;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='12' ows_owshiddenversion='1'
ows_UniqueId='12;#{7C58052F-65B8-4FFE-9669-B19C1BA2A36F}'
ows_FSObjType='12;#0' ows_Created='2011-05-05 19:21:50'
ows_FileRef='12;#Custom WebParts/Lists/Tasks/12_.000'
ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task011' ows_Status='In
Progress' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='11;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='11' ows_owshiddenversion='1'
ows_UniqueId='11;#{BFDFD18D-3BB6-4C52-9728-7B336CB6F9F9}'
ows_FSObjType='11;#0' ows_Created='2011-05-05 19:21:22'
ows_FileRef='11;#Custom WebParts/Lists/Tasks/11_.000'
ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task010' ows_Status='Not
Started' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='10;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='10' ows_owshiddenversion='5'
ows_UniqueId='10;#{F7B2CB7C-140D-45EF-A755-15D881D0FBCE}'
ows_FSObjType='10;#0' ows_Created='2011-05-05 18:19:51'
ows_FileRef='10;#Custom WebParts/Lists/Tasks/10_.000'
ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task009' ows_Status='Not
Started' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='9;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='9' ows_owshiddenversion='7' ows_UniqueId='9;#{54A816D9-
BD3D-472F-96C0-6C8B574A1499}' ows_FSObjType='9;#0'
ows_Created='2011-05-05 18:18:52' ows_FileRef='9;#Custom WebParts/
Lists/Tasks/9_.000' ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task008' ows_Status='Not
Started' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='8;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='8' ows_owshiddenversion='5'
ows_UniqueId='8;#{4974F85F-03A3-4B50-AADB-A91587DE5B26}'
ows_FSObjType='8;#0' ows_Created='2011-05-05 18:18:52'
ows_FileRef='8;#Custom WebParts/Lists/Tasks/8_.000'
ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task007' ows_Status='Not
Started' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='7;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='7' ows_owshiddenversion='7'
ows_UniqueId='7;#{E8B645C5-3A64-497E-B5CB-0ADE24B24A29}'
ows_FSObjType='7;#0' ows_Created='2011-05-05 18:18:19'
ows_FileRef='7;#Custom WebParts/Lists/Tasks/7_.000'
ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task006' ows_Status='Not
Started' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='6;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='6' ows_owshiddenversion='5' ows_UniqueId='6;#{AA8881D4-
A5F7-4D3C-ADF6-881212EF66E9}' ows_FSObjType='6;#0'
ows_Created='2011-05-05 18:18:08' ows_FileRef='6;#Custom WebParts/
Lists/Tasks/6_.000' ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task005' ows_Status='Waiting
on someone else' ows_Priority='High' ows_AssignedTo='8;#Venkata
Narasimha B. Prasad' ows_MetaInfo='5;#' ows__ModerationStatus='0'
ows__Level='1' ows_ID='5' ows_owshiddenversion='5'
ows_UniqueId='5;#{E2E7AAED-8A1C-4303-B55B-DA28049A05E3}'
ows_FSObjType='5;#0' ows_Created='2011-05-03 17:07:36'
ows_FileRef='5;#Custom WebParts/Lists/Tasks/5_.000'
ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task004'
ows_Status='Deferred' ows_Priority='High' ows_AssignedTo='8;#Venkata
Narasimha B. Prasad' ows_MetaInfo='4;#' ows__ModerationStatus='0'
ows__Level='1' ows_ID='4' ows_owshiddenversion='2'
ows_UniqueId='4;#{AC0F889C-F681-4BAE-BEF0-D63FE2F79749}'
ows_FSObjType='4;#0' ows_Created='2011-05-03 17:07:11'
ows_FileRef='4;#Custom WebParts/Lists/Tasks/4_.000'
ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task003'
ows_Status='Completed' ows_Priority='High' ows_AssignedTo='8;#Venkata
Narasimha B. Prasad' ows_MetaInfo='3;#' ows__ModerationStatus='0'
ows__Level='1' ows_ID='3' ows_owshiddenversion='2'
ows_UniqueId='3;#{E6A52BB7-2B97-4B4D-8871-117C6A2E4F1C}'
ows_FSObjType='3;#0' ows_Created='2011-05-03 17:06:48'
ows_FileRef='3;#Custom WebParts/Lists/Tasks/3_.000'
ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task002' ows_Status='In
Progress' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='2;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='2' ows_owshiddenversion='2' ows_UniqueId='2;#{9B4F69AF-
A97F-4CE8-878E-43C76FC04545}' ows_FSObjType='2;#0'
ows_Created='2011-05-03 17:06:16' ows_FileRef='2;#Custom WebParts/
Lists/Tasks/2_.000' ows_ServerRedirected='0'/>
<z:row xmlns:z='#RowsetSchema' ows_Title='Task001' ows_Status='Not
Started' ows_Priority='High' ows_AssignedTo='8;#Venkata Narasimha B.
Prasad' ows_MetaInfo='1;#' ows__ModerationStatus='0' ows__Level='1'
ows_ID='1' ows_owshiddenversion='2' ows_UniqueId='1;#{19F69580-
B910-4455-B154-3DC15C5E29AE}' ows_FSObjType='1;#0'
ows_Created='2011-05-03 17:05:53' ows_FileRef='1;#Custom WebParts/
Lists/Tasks/1_.000' ows_ServerRedirected='0'/>