S\u0130ND\u0130R\u0130M S\u0130STEM\u0130NE GENEL BAKI\u015e<\/p>\n
Sindirim sistemi, yakla\u015f\u0131k 9 m uzunlu\u011funda olan sindirim kanal\u0131, bu kanala sindirim olay\u0131yla ilgili salg\u0131lar\u0131n\u0131 ak\u0131tan \u201cSalg\u0131 bezleri\u201d ve di\u015flerden olu\u015fmu\u015ftur. Sindirim kanal\u0131n\u0131n b\u00f6l\u00fcmlerini a\u011f\u0131zdan ba\u015flayarak s\u0131ralarsak \u015fu b\u00f6l\u00fcmlerle kar\u015f\u0131la\u015f\u0131r\u0131z:<\/p>\n
1) A\u011f\u0131z bo\u015flu\u011fu
\n2) Farinks (yutak)
\n3) \u00d6zofagus (yemek borusu)
\n4) Mide
\n5) \u0130nceba\u011f\u0131rsaklar
\na) Duodenum (onikiparmak ba\u011f\u0131rsa\u011f\u0131)
\nb) Jejunum
\nc) \u0130leum
\n6) Kal\u0131nba\u011f\u0131rsaklar
\na) Kolonlar
\nb) Rektum
\nc) Anus<\/p>\n
Sindirim olay\u0131nda \u00e7ok \u00f6nemli yard\u0131mc\u0131 i\u015flevler \u00fcstlenmi\u015f olan olu\u015fumlar\u0131 \u015f\u00f6yle s\u0131ralayabiliriz: 1) Di\u015fler, 2) T\u00fck\u00fcr\u00fck bezleri, 3) Sindirim kanal\u0131n\u0131n duvarlar\u0131nda bulunan salg\u0131 bezleri, 4) Karaci\u011fer ve pankreas.<\/p>\n
\u00d6ZOFAGUS (YEMEK BORUSU): \u00d6zofagus, farinks ile mideyi birle\u015ftiren, yakla\u015f\u0131k olarak 25 cm uzunlu\u011funda \u00f6nemli b\u00f6l\u00fcm\u00fc kastan yap\u0131lm\u0131\u015f t\u00fcp bi\u00e7iminde bir organd\u0131r. \u00d6zofagusun \u00fcst s\u0131n\u0131r\u0131 6. boyun omuru hizas\u0131nda, alt s\u0131n\u0131r\u0131 da 11. s\u0131rt omuru hizas\u0131ndad\u0131r. \u00d6zofagus yukar\u0131dan a\u015fa\u011f\u0131ya do\u011fru \u201cBoyun b\u00f6l\u00fcm\u00fc\u201d, \u201cG\u00f6\u011f\u00fcs bo\u015flu\u011fu b\u00f6l\u00fcm\u00fc\u201d ve \u201cKar\u0131n bo\u015flu\u011fu b\u00f6l\u00fcm\u00fc\u201d olmak \u00fczere \u00fc\u00e7 b\u00f6l\u00fcmden olu\u015fmu\u015ftur.<\/p>\n
\u00d6zofagus, boyun b\u00f6l\u00fcm\u00fcnde nefes borusunun arkas\u0131nda, boyun omurlar\u0131n\u0131 \u00f6n\u00fcnde bulunur. Tiroit bezinin loplar\u0131 ve \u201cArteria karotis komunis\u201d adl\u0131 atardamarlar, sa\u011fda ve solda olmak \u00fczere \u00f6zofagusun boyun b\u00f6l\u00fcm\u00fcyle kom\u015fuluk ederler. \u00d6zofagus g\u00f6\u011f\u00fcs kafesi bo\u015flu\u011funa girdi\u011finde \u00f6nce trakean\u0131n arkas\u0131nda yol al\u0131r. Buradan a\u015fa\u011f\u0131 do\u011fru inerken, hafif\u00e7e sola kayar. Bu s\u0131rada, aorta kavisinin sa\u011f\u0131nda sol esas bron\u015fun da arkas\u0131nda bulunmaktad\u0131r. A\u015fa\u011f\u0131 indik\u00e7e aorta damar\u0131n\u0131n g\u00f6\u011f\u00fcs b\u00f6l\u00fcm\u00fcn\u00fcn sa\u011f\u0131ndan, hafif\u00e7e soluna ge\u00e7er. Daha sonra kar\u0131n bo\u015flu\u011fuyla g\u00f6\u011f\u00fcs bo\u015flu\u011funu birbirinden ay\u0131rmakta olan \u201cDiyafragma\u201d ad\u0131ndaki kas\u0131 delerek, kar\u0131n bo\u015flu\u011funa ge\u00e7er. \u00d6zofagus, kar\u0131n bo\u015flu\u011fu i\u00e7inde \u00e7ok k\u0131sa bir yol ald\u0131ktan sonra midenin giri\u015f deli\u011fi olarak niteleyece\u011fimiz \u201cKardia\u201d adl\u0131 mide deli\u011fine ge\u00e7er. \u00d6zofagusun diyafragmadaki delikten ge\u00e7ti\u011fi b\u00f6lge 10. s\u0131rt omuru hazs\u0131ndad\u0131r.<\/p>\n
Midenin kardia adl\u0131 deli\u011fine a\u00e7\u0131ld\u0131\u011f\u0131 yer ise 11. s\u0131rt omurunun d\u00fczeyine uyar.<\/p>\n
\u00d6zofagusun baz\u0131 b\u00f6lgelerinde darl\u0131klar vard\u0131r. Bu darl\u0131klardan ilki kesici di\u015flerden 15 cm uzakl\u0131kta bulunmaktad\u0131r. \u0130kinci darl\u0131k \u00f6zofagusun aorta kavisini \u00e7aprazlad\u0131\u011f\u0131 b\u00f6lgede, kesici di\u015flerden 22.5 cm uzaktad\u0131r. \u00dc\u00e7\u00fcnc\u00fc darl\u0131k kesici di\u015flerden 27.5 cm uzakl\u0131kta olup, \u00f6zofagusun sol esas bron\u015fla \u00e7aprazla\u015ft\u0131\u011f\u0131 b\u00f6lgeye uymaktad\u0131r. D\u00f6rd\u00fcnc\u00fc ve son darl\u0131kta kesici di\u015flerden 40 cm uzakta olup, \u00f6z\u0131fagusun diyafragmay\u0131 ge\u00e7ti\u011fi b\u00f6lgeye uymaktad\u0131r. Bu darl\u0131klar\u0131n bilinmesi, \u00f6zellikle doktorlar i\u00e7in \u00f6nemlidir. \u00c7\u00fcnk\u00fc gastroskop denilen ve te\u015fhis\/tedavi ama\u00e7lar\u0131yla mideye kadar g\u00f6nderilen bir aletin hortum bi\u00e7imindeki b\u00f6l\u00fcm\u00fc, bu darl\u0131klardan ge\u00e7erken biraz zorlan\u0131r. <\/p>\n
\u00d6zofagus kas liflerinden zengin bir dokuya sahiptir. Bu kaslar\u0131n ritmik olarak kas\u0131l\u0131p gev\u015femeleriyle, yutulan lokmalar \u00f6zofagus yoluyla mideye ta\u015f\u0131n\u0131rlar. Nitekim ba\u015f a\u015fa\u011f\u0131 duran bir insan bile, a\u011fz\u0131ndaki lokmay\u0131 yuttu\u011funda \u00f6zofagus bu ritmik kas\u0131lmalar\u0131n\u0131n yard\u0131m\u0131yla lokma mideye kadar ta\u015f\u0131n\u0131r. S\u00f6z\u00fcn\u00fc etti\u011fimiz bu ritmik kas\u0131lma ve gev\u015feme hareketlerine \u201cPeristaltik hareketler\u201d denir.<\/p>\n
\u00d6zofagustaki peristaltik hareketleri k\u0131saca \u015f\u00f6yle anlatabiliriz: Yutulan lokma \u00f6zofagus bo\u015fluna geldi\u011finde, bu b\u00f6lge kas\u0131l\u0131r. Bu s\u0131rada kas\u0131lan b\u00f6lgenin hemen alt\u0131ndaki b\u00f6lge gev\u015fektir. Kas\u0131lm\u0131\u015f olan b\u00f6lgede \u00f6zofagus bo\u015flu\u011fu daralaca\u011f\u0131ndan, i\u00e7indeki lokmay\u0131 bir alttaki gev\u015fek b\u00f6lgeye iter. Bu kez biraz \u00f6nce gev\u015fek olan b\u00f6l\u00fcm kas\u0131larak, i\u00e7indeki lokmay\u0131 bir alttaki gev\u015fek b\u00f6lgeye g\u00f6nderir. Bu s\u0131rada ilk kas\u0131lan b\u00f6lge gev\u015fer ve yeni gelecek olan lokmaya haz\u0131rlan\u0131r. Bu bi\u00e7imde lokmalar mideye kadar ta\u015f\u0131n\u0131r. Bu olaylar\u0131n d\u00fczenlenmesinde, \u00f6zofagus kaslar\u0131n\u0131 kas\u0131lmaya y\u00f6nelten sinir sisteminin \u00e7ok b\u00fcy\u00fck rol\u00fc vard\u0131r.<\/p>\n
M\u0130DE: Mide, \u00f6zofagusun sonuyla duodenumun (onikiparmak ba\u011f\u0131rsa\u011f\u0131) ba\u015flang\u0131c\u0131 aras\u0131ndaki ba\u011flant\u0131y\u0131 sa\u011flamaktad\u0131r. Sindirim kanal\u0131n\u0131n en geni\u015f b\u00f6l\u00fcm\u00fc midedir. Yeni do\u011fan bir \u00e7ocukta midenin kapasitesi 30 mililitre iken bu kapasite ergenlik \u00e7a\u011f\u0131nda 1000 mililitreye kadar \u00e7\u0131kar. <\/p>\n
Midenin iki deli\u011fi, iki y\u00fcz\u00fc ve iki de kenar\u0131 bulunmaktad\u0131r. Midenin ilk deli\u011fi mide ile \u00f6zofagusun a\u011f\u0131zla\u015ft\u0131\u011f\u0131 noktadad\u0131r. Buna \u201ckardia deli\u011fi\u201d denir. Kardia deli\u011fi 11. s\u0131rt omuru hizas\u0131ndad\u0131r. G\u00f6\u011f\u00fcs \u00f6n duvar\u0131ndan 10 cm derindedir. <\/p>\n
Kesici di\u015flerden uzakl\u0131\u011f\u0131 40 cm kadard\u0131r. \u00d6zofagusun sol kenar\u0131 kardia deli\u011fi hizas\u0131nda midenin sol kenar\u0131 ile dar bir a\u00e7\u0131 yaparak birle\u015fir. Bu b\u00f6l\u00fcme \u201ckardia \u00e7enti\u011fi\u201d denir. Kardia \u00e7enti\u011fi d\u00fczeyinin \u00fcst\u00fcnde kalan mide b\u00f6l\u00fcm\u00fcne \u201cfundus\u201d ad\u0131 verilir. Midenin di\u011fer b\u00f6l\u00fcm\u00fcne \u201cpilor deli\u011fi\u201d denir. Pilor deli\u011finin kar\u0131n \u00f6n duvar\u0131ndaki izd\u00fc\u015f\u00fcm\u00fc v\u00fccudunun orta-dikey hatt\u0131n\u0131n 1. omurundan ge\u00e7en yatay hat kesi\u015fme noktas\u0131n\u0131n 1-2 cm sa\u011f\u0131ndad\u0131r. Mide bo\u015flu\u011fu arac\u0131l\u0131\u011f\u0131yla duodenum bo\u015flu\u011funa ba\u011flan\u0131r, yukar\u0131da da kardia deli\u011fi arac\u0131l\u0131\u011f\u0131yla \u00f6zofagus bo\u015flu\u011funa ba\u011flanm\u0131\u015ft\u0131r.<\/p>\n
Genel bir kural olarak, daha do\u011frusu normal ko\u015fullarda besinlerin ak\u0131\u015f\u0131 \u00f6zofagustan mideye, mideden de duodenuma do\u011frudur. Ancak bu de\u011fi\u015fmez bir kural de\u011fildir. Mideye do\u011fru olan geri ak\u0131ma \u201creg\u00fcrjitasyon\u201d denir. Bu mideden \u00f6zofagusa do\u011fru da olabilir. Di\u011fer bir anlat\u0131mla, sindirim kanl\u0131nda besinlerin normal yollar\u0131n\u0131n tersine olarak, bir b\u00f6lgeden ba\u015fka bir b\u00f6lgeye geri ge\u00e7melerine reg\u00fcrjitasyon denir. Bu normal bir olay de\u011fildir. Midenin iki kenar\u0131n\u0131n bulundu\u011funu belirtmi\u015ftik. Bu kenarlardan biri midenin sa\u011f\u0131nda, di\u011feri de solunda bulunmaktad\u0131r. Sa\u011fdaki kenara \u201ck\u00fc\u00e7\u00fck kenar\u201d, soldakine de \u201cb\u00fcy\u00fck kenar\u201d denir.<\/p>\n
Midenin k\u00fc\u00e7\u00fck kenar\u0131 midenin sa\u011f\u0131nda kardia ile pilor delikleri aras\u0131nda uzanmaktad\u0131r. K\u00fc\u00e7\u00fck kenar, yukar\u0131dan a\u015fa\u011f\u0131 do\u011fru bir s\u00fcre \u00f6zofagus sa\u011f kenar\u0131yla ayn\u0131 do\u011frultuda devam ettikten sonra, kendi \u00fczerinde sa\u011fa do\u011fru a\u00e7\u0131la\u015farak devam eder. Bu a\u00e7\u0131la\u015fman\u0131n en keskin oldu\u011fu b\u00f6lgeye \u201cangular insisura\u201d denir. Midenin solunda bulunan b\u00fcy\u00fck kenar, k\u00fc\u00e7\u00fck kenardan 4-5 kat daha uzundur. <\/p>\n
B\u00fcy\u00fck kenar da midenin iki deli\u011fi aras\u0131nda uzanmaktad\u0131r. \u00dcstte, kardia \u00e7enti\u011fi d\u00fczeyinin \u00fcst\u00fcnde kalan b\u00fcy\u00fck kenar b\u00f6l\u00fcm\u00fc, midenin fundus b\u00f6lgesine aittir. B\u00fcy\u00fck kenar \u201cangular insisura\u201dn\u0131n hemen kar\u015f\u0131s\u0131na rastlayan b\u00f6lgede bir \u015fi\u015flik g\u00f6sterir. Bu \u015fi\u015flik, midenin \u201cpilor\u201d b\u00f6l\u00fcm\u00fcn\u00fcn ba\u015flang\u0131c\u0131na uymaktad\u0131r. Pilor b\u00f6lgesi, sa\u011fda pilor deli\u011fi ile son bulmaktad\u0131r. Midenin pilor b\u00f6lgesi asl\u0131nda ikiye ayr\u0131lm\u0131\u015ft\u0131r. Bunlardan solda ve \u201cinsisura angularis\u201de daha yak\u0131n olan\u0131na \u201cantrum\u201d denir. Sa\u011fda olan\u0131na \u201cpilor kanal\u0131\u201d denir. Pilor kanal\u01312-3 cm kadard\u0131r. Antrumla pilor kanal\u0131 aras\u0131nda, b\u00fcy\u00fck kenarda bir \u00e7\u00f6k\u00fcnt\u00fc g\u00f6r\u00fcl\u00fcr. Bu \u00e7\u00f6k\u00fcnt\u00fc pilor kanal\u0131yla antrum aras\u0131ndaki s\u0131n\u0131r\u0131 \u00e7izer ve \u201csulkus intermedius\u201d ad\u0131n\u0131 al\u0131r. <\/p>\n
Mide bo\u015fken duvarlar\u0131 birbirine de\u011fer. Bo\u015f durumdaki midenin duvarlar\u0131n\u0131, duru\u015fu gere\u011fi \u00fcst ve alt olarak adland\u0131rmak gerekir. Oysa mide dolu oldu\u011funda \u00f6n duvar \u201c\u00fcst\u201d, arka duvar da \u201calt\u201d duvar olmak \u00fczere durum de\u011fi\u015ftirir. Bu nedenle midenin bu iki durumunu da tan\u0131mlayan \u015fu terimler daha uygundur: \u201c\u00f6n-\u00fcst duvar\u201d ve \u201carka-alt duvar\u201d.<\/p>\n
Midenin i\u00e7 y\u00fcz\u00fc incelendi\u011finde, mide duvarlar\u0131n\u0131n mide bo\u015flu\u011funa do\u011fru \u00e7ok say\u0131da k\u0131vr\u0131mlar bi\u00e7iminde \u00e7\u0131k\u0131nt\u0131lar yapt\u0131\u011f\u0131 g\u00f6r\u00fcl\u00fcr. Pilor deli\u011finin \u00e7evresinin de pilor kanal\u0131n\u0131n duvar\u0131ndan kaynaklanan bir \u00e7\u0131k\u0131nt\u0131yla kapand\u0131\u011f\u0131 g\u00f6r\u00fcl\u00fcr. Bu \u00e7\u0131k\u0131nt\u0131 midenin \u201cpilor sfinkteri\u201dne ba\u011fl\u0131d\u0131r. Pilor sfinkteri midenin bu b\u00f6lgesinde kaslar\u0131n kal\u0131nla\u015farak olu\u015fturduklar\u0131 bir b\u00fczgendir. <\/p>\n
DUODENUM (ON\u0130K\u0130PARMAK BA\u011eIRSA\u011eI): \u0130nceba\u011f\u0131rsa\u011f\u0131n toplam uzunlu\u011fu 6-7 m kadard\u0131r, ancak bu uzunlu\u011fun ilk 25 cm \u2018lik b\u00f6l\u00fcm\u00fc duodenuma aittir. Buna g\u00f6re duodenum, inceba\u011f\u0131rsa\u011f\u0131n en k\u0131sa b\u00f6l\u00fcm\u00fcn\u00fc olu\u015fturmaktad\u0131r. Duodenumun \u201cmezenter\u201di yoktur ve k\u0131smen peritonla \u00f6rt\u00fcl\u00fcd\u00fcr. Duodenum mideyle jejunum aras\u0131ndaki ba\u011flant\u0131y\u0131 sa\u011flamaktad\u0131r. Genel olarak C harfine benzetebilece\u011fimiz duodenum, pankreas ba\u015f\u0131n\u0131 \u00e7evrelemektedir. Kar\u0131n \u00f6n duvar\u0131nda g\u00f6bekten ge\u00e7en yatay tasar\u0131msal bir \u00e7izgi \u00e7izdi\u011fimizde, duodenum bu \u00e7izginin \u00fcst\u00fcndeki b\u00f6lgede kal\u0131r. <\/p>\n
Duodenum \u00fc\u00e7 dirsek yapmaktad\u0131r. Bunlardan birincisine \u201c\u00fcst fleksura\u201d, ikincisine \u201calt fleksura\u201d, \u00fc\u00e7\u00fcnc\u00fcs\u00fcne de \u201cdudenojejunal fleksura\u201d denir. Bu dirsekler arac\u0131l\u0131\u011f\u0131yla duodenum, kabaca C\u2019ye benzeyen bir bi\u00e7im kazanmaktad\u0131r. Dirsekler g\u00f6z \u00f6n\u00fcne al\u0131nd\u0131\u011f\u0131nda, duodenum ba\u015fl\u0131ca d\u00f6rt b\u00f6l\u00fcme ayr\u0131l\u0131r. Yakla\u015f\u0131k 5 cm uzunlu\u011funda olan ilk b\u00f6l\u00fcm, \u201cpilor deli\u011fi\u201d ile \u201c\u00fcst fleksura\u201d aras\u0131nda uzanmakta ve \u201c\u00fcst b\u00f6l\u00fcm\u201d ad\u0131n\u0131 almaktad\u0131r. \u00dcst b\u00f6l\u00fcm\u00fcn \u00f6n y\u00fcz\u00fc peritonla \u00f6rt\u00fcl\u00fcyken, arka y\u00fcz\u00fc peritonsuzdur. \u201c\u00dcst fleksura\u201d b\u00f6lgesinde, safra kesesi boynu ile duodenum birbiriyle kom\u015fudurlar. Duodenumun \u00fcst b\u00f6l\u00fcm\u00fcn\u00fcn \u00f6n y\u00fcz\u00fc karaci\u011fer ve safra kesesiyle kom\u015fuluk yapmaktad\u0131r. \u00dcst b\u00f6l\u00fcm\u00fcn arka y\u00fcz\u00fc de \u201cvena porta\u201d, \u201cana safra kanal\u0131\/koledok\u201d ve \u201cpankreas\u201d ile kom\u015fudur. Duodenumun ikinci b\u00f6l\u00fcm\u00fcne \u201cinen b\u00f6l\u00fcm\u201d denir. 8-10 cm boyunda olan bu b\u00f6l\u00fcm, \u00fcst ve alt fleksuralar aras\u0131nda uzanmaktad\u0131r. \u0130nen b\u00f6l\u00fcm \u00f6nde karaci\u011fer ve transvers kolonla kom\u015fudur. Arka y\u00fcz\u00fc de sa\u011f b\u00f6brek ve vena kava inferiorla kom\u015fudur. Ana safra kanal\u0131yla pankreas kanal\u0131, duodenumun inen b\u00f6l\u00fcm\u00fcn\u00fcn i\u00e7 yan taraf\u0131ndaki duvar\u0131na e\u011fik bir gidi\u015fle ayr\u0131 ayr\u0131 girdikten sonra, bir s\u00fcre duvar\u0131n i\u00e7inde yol al\u0131rlar. Daha sonra birbirleriyle birle\u015ferek tek bir kanal olu\u015ftururlar.<\/p>\n
Olu\u015fan bu yeni kanala \u201chepatopankreatik ampula\u201d denir. Hepatopankreatik ampula, doudenumun inen b\u00f6l\u00fcm\u00fcn\u00fcn i\u00e7 yan duvar\u0131na pilordan 8-10 cm uzakl\u0131kta bir kabart\u0131 yaparak a\u00e7\u0131l\u0131r. Bu kabart\u0131ya \u201cb\u00fcy\u00fck duodenal papilla\u201d ya da \u201cvater papillas\u0131\u201d denir. Bazen buna ek olarak k\u00fc\u00e7\u00fck ve ayr\u0131 bir pankreas kanal\u0131 da duodenuma a\u00e7\u0131lmaktad\u0131r. Bu kanala \u201caksesuar pankreatik kanal\u201d denir. Bu kanal \u201cb\u00fcy\u00fck duodenal papilla\u201dn\u0131n 2 cm \u00fcst\u00fcnde bir kart\u0131ta neden olmaktad\u0131r. Bu kabart\u0131ya da \u201ck\u00fc\u00e7\u00fck duodenal papilla\u201d denir. Duodenumun \u00fc\u00e7\u00fcnc\u00fc b\u00f6l\u00fcm\u00fc \u201chorizontal b\u00f6l\u00fcm\u201d (yatay b\u00f6l\u00fcm) ad\u0131n\u0131 al\u0131r ve yakla\u015f\u0131k 10 cm uzunlu\u011fundad\u0131r. Horizontal b\u00f6l\u00fcm, kar\u0131n aortas\u0131n\u0131n \u00f6n\u00fcnde sona erer. \u00d6n y\u00fcz\u00fc peritonla kapl\u0131d\u0131r. Duodenumun son b\u00f6l\u00fcm\u00fcne, \u201c\u00e7\u0131kan b\u00f6l\u00fcm\u201d denir ve yakla\u015f\u0131k 2,5 cm uzunlu\u011fundad\u0131r. Bu b\u00f6l\u00fcm \u201cdudenojejunal fleksura\u201dy\u0131 olu\u015fturduktan sonra jejunumla birle\u015fir. Duodenumun \u00fcst b\u00f6l\u00fcmleri biraz hareketli, buna kar\u015f\u0131l\u0131k alt b\u00f6l\u00fcmleri hareketsidir. Baryumlu bir maddenin yap\u0131lan r\u00f6ntgen incelemede, midenin pilor kanal\u0131ndan hemen sonraki duodenum b\u00f6lgesinin taban\u0131n\u0131n pilora bakan bir \u00fc\u00e7gen g\u00f6r\u00fcn\u00fcm\u00fcnde oldu\u011fu g\u00f6r\u00fcl\u00fcr. R\u00f6ntgende \u00fc\u00e7gen olarak g\u00f6r\u00fclen duodenumun bu b\u00f6lgesine \u201cbulbus\u201d denir. Bulbus b\u00f6lgesinde \u00fclser geli\u015fme s\u0131kl\u0131\u011f\u0131 fazlad\u0131r. Duodenumun jejunuma birle\u015fti\u011fi noktaya diyafragmadan kas ve lifsel yap\u0131da bir ba\u011f uzanmaktad\u0131r. Buna \u201ctreitz\u201d ya da \u201c treitz fasyas\u0131\u201d denir. Treitz kas\u0131ndan \u00f6nceki sindirim kanal\u0131 kanamalar\u0131nda kan, d\u0131\u015fk\u0131 i\u00e7inde sindirilmi\u015f olarak \u00e7\u0131kar. Bu noktadan sonraki kanamalarda ise kan, sindirilmemi\u015f olarak d\u0131\u015fk\u0131 i\u00e7inde \u00e7\u0131kar. <\/p>\n
JEJUNUM VE \u0130LEUM: \u0130nceba\u011f\u0131rsa\u011f\u0131n duodenumdan sonraki b\u00f6l\u00fcm\u00fc \u201cjejunum\u201d ve \u201cileum\u201d taraf\u0131ndan olu\u015fturulmaktad\u0131r. D\u0131\u015f g\u00f6r\u00fcn\u00fc\u015f\u00fc bo\u011fumlu olan inceba\u011f\u0131rsa\u011f\u0131n bu ilk 2\/5\u2019lik b\u00f6l\u00fcm\u00fc \u201cjejunum\u201d, son 3\/5\u2019lik b\u00f6l\u00fcm\u00fc de \u201cileum\u201d ad\u0131n\u0131 al\u0131r. \u0130leumu jejunumdan ay\u0131ran kesin bir \u00e7izgi yoktur. \u0130nceba\u011f\u0131rsak dokusal \u00f6zellikleri bak\u0131m\u0131ndan incelendi\u011finde, jejunumun yava\u015f yava\u015f ileuma d\u00f6n\u00fc\u015ft\u00fc\u011f\u00fc g\u00f6r\u00fcl\u00fcr. \u0130nceba\u011f\u0131rsa\u011f\u0131n jejunum-ileum b\u00f6l\u00fcm\u00fc, jejunumun duodenuma birle\u015fti\u011fi b\u00f6lgeden ve ileumun kal\u0131nba\u011f\u0131rsa\u011f\u0131n ba\u015flang\u0131c\u0131 olan \u201c\u00e7ekum\u201d ile birle\u015fti\u011fi noktada biter. \u0130leumun \u00e7ekuma a\u00e7\u0131ld\u0131\u011f\u0131 noktada, ba\u011f\u0131rsak dokusunun \u00f6\u011felerinden yap\u0131lm\u0131\u015f \u201cileo\u00e7ekal valv\u00fcl\u201d denilen bir kapak bulunmaktad\u0131r. Bu kapak normal ko\u015fullarda ileumdaki sindirilmi\u015f besinlerin tek y\u00f6nl\u00fc olarak ge\u00e7i\u015flerini sa\u011flamaktad\u0131r.<\/p>\n
Jejunum 4 cm \u00e7ap\u0131ndad\u0131r. Duvar\u0131 ileuma oranla daha kal\u0131n, daha k\u0131rm\u0131z\u0131 ve daha damarl\u0131d\u0131r. \u0130leumun \u00e7ap\u0131 ise 3.5 cm kadard\u0131r ve duvar\u0131 daha incedir. Jejunumun b\u00fcy\u00fck bir b\u00f6l\u00fcm\u00fc \u201cg\u00f6bek b\u00f6lgesi\u201dnde, ileumun b\u00fcy\u00fck bir b\u00f6l\u00fcm\u00fc de \u201chipogastrik b\u00f6lge\u201dde bulunmaktad\u0131r. Jejunum ve ileum hemen hemen t\u00fcm\u00fcyle peritonla \u00f6rt\u00fcl\u00fcd\u00fcr. <\/p>\n
KALINBA\u011eIRSAK: Kal\u0131nba\u011f\u0131rsak, anusa kadar uzanmaktad\u0131r ve uzunlu\u011fu yakla\u015f\u0131k 1.5 m kadard\u0131r. Kal\u0131nba\u011f\u0131rsakta inceleyebilece\u011fimiz b\u00f6l\u00fcmleri \u015f\u00f6yle s\u0131ralayabiliriz: \u201cApendiks vermiformis\u201d, \u201c\u00e7ekum ve ileo\u00e7ekal valv\u00fcl\u201d, \u201c\u00e7\u0131kan kolon\u201d, \u201chorizontal kolon\u201d, \u201cinen kolon\u201d, \u201csigmoid\u201d, \u201crektum\u201d ve \u201canus\u201d. Kal\u0131nba\u011f\u0131rsa\u011f\u0131n ba\u015flang\u0131\u00e7 b\u00f6l\u00fcm\u00fcn\u00fcn kar\u0131n \u00f6n duvar\u0131ndaki izd\u00fc\u015f\u00fcm\u00fc \u201csa\u011f iliak\u201d b\u00f6lgeye uymaktad\u0131r. Bu b\u00f6lgede \u201c\u00e7ekum\u201d denilen ve kal\u0131nba\u011f\u0131rsa\u011f\u0131n ba\u015flang\u0131c\u0131n\u0131 olu\u015fturan geni\u015flemi\u015f bir b\u00f6l\u00fcm bulunmaktad\u0131r. \u00c7ekuma inceba\u011f\u0131rsa\u011f\u0131n \u201cileum\u201d b\u00f6l\u00fcm\u00fc ve \u201capendiks vermiformis\u201d a\u00e7\u0131lmaktad\u0131r. Kal\u0131nba\u011f\u0131rsak \u00e7ekumdan sonra yukar\u0131 do\u011fru y\u00fckselir. Kal\u0131n ba\u011f\u0131rsa\u011f\u0131n bu b\u00f6l\u00fcm\u00fcne \u201c\u00e7\u0131kan kolon\u201d denir. \u00c7\u0131kan kolon, a\u015fa\u011f\u0131dan yukar\u0131ya do\u011fru \u00f6nce \u201csa\u011f iliak\u201d b\u00f6lgede daha sonra da \u201csa\u011f lumbal\u201d b\u00f6lgede ilerler. Burada karaci\u011ferin alt\u0131na ula\u015ft\u0131\u011f\u0131nda sola do\u011fru bir dirsek yaparak k\u0131vr\u0131l\u0131r. Bu dirse\u011fe \u201cfleksura kolika dekstra\u201d denir. Kolon, \u201cfleksura kolika dekstra\u201dy\u0131 yapt\u0131ktan sonra v\u00fccudun sol taraf\u0131na yatay olarak ilerler ve a\u00e7\u0131kl\u0131\u011f\u0131 yukar\u0131ya bakan bir e\u011fiklik yapar. Kal\u0131nba\u011f\u0131rsa\u011f\u0131n bu b\u00f6l\u00fcm\u00fcne \u201ctransvers kolon\u201d denir. Transvers kolon sola do\u011fru y\u00f6nelirken sa\u011f lumbal b\u00f6lgeden, umbilikal b\u00f6lgeden, epigastrik b\u00f6lgeden ge\u00e7er ve \u201csol hipokondriak\u201d b\u00f6lgeye ula\u015f\u0131r. Kal\u0131nba\u011f\u0131rsak burada da bir dirsek yaparak a\u015fa\u011f\u0131 y\u00f6nelir. Kal\u0131nba\u011f\u0131rsa\u011f\u0131n sol hipokondriak b\u00f6lgede yapt\u0131\u011f\u0131 dirse\u011fe \u201cfleksura kolika sinistra\u201d denir. Kal\u0131nba\u011f\u0131rsak sol hipokondriak b\u00f6lgede dirse\u011fini yapt\u0131ktan sonra a\u015fa\u011f\u0131ya, k\u00fc\u00e7\u00fck pelvise do\u011fru inmeye ba\u015flar. Kal\u0131nba\u011f\u0131rsa\u011f\u0131n bu b\u00f6l\u00fcm\u00fcne \u201cinen kolon\u201d denir. \u0130nen kolonun katetti\u011fi yol boyunca kar\u0131n \u00f6n duvar\u0131ndaki izd\u00fc\u015f\u00fcmleri \u015fu b\u00f6lgelerden ge\u00e7mektedir: Sol hipokondriak b\u00f6lge, sol lumbal (bel) b\u00f6lge, sol iliak b\u00f6lge. \u0130nen kolon daha sonra kal\u0131nba\u011f\u0131rsa\u011f\u0131n \u201csigmoid kolon\u201d denilen b\u00f6l\u00fcm\u00fcne a\u00e7\u0131l\u0131r. B\u00f6ylece kal\u0131nba\u011f\u0131rsa\u011f\u0131n kolon b\u00f6l\u00fcm\u00fc tamamlanm\u0131\u015f olur. Sigmoid kolon daha sonra kal\u0131nba\u011f\u0131rsa\u011f\u0131n \u201crektum\u201d adl\u0131 b\u00f6l\u00fcm\u00fcne a\u00e7\u0131l\u0131r. Rektum da kal\u0131nba\u011f\u0131rsa\u011f\u0131n son b\u00f6l\u00fcm\u00fc olan \u201canus\u201da a\u00e7\u0131lmaktad\u0131r.<\/p>\n
Kal\u0131nba\u011f\u0131rsa\u011f\u0131n yap\u0131s\u0131nda bulunan ve uzunlamas\u0131na seyretmekte olan d\u00fcz kas lifleri, kal\u0131nba\u011f\u0131rsa\u011f\u0131n uzunlu\u011fu boyunca seyretmekte olan \u00fc\u00e7 bant olu\u015ftururlar. Bu bantlara \u201ctenia koli\u201d denir. Kal\u0131nba\u011f\u0131rsa\u011f\u0131n peritonla \u00f6rt\u00fcl\u00fc serbest b\u00f6l\u00fcmlerinde, periton yapraklar\u0131 aras\u0131nda ya\u011f k\u00fcmeciklerinin olu\u015fturdu\u011fu \u015fi\u015flikler g\u00f6r\u00fcl\u00fcr. Bunlara \u201capendiks epiploika\u201d denir. <\/p>\n
\u00c7EKUM VE \u0130LEO\u00c7EKAL VALV\u00dcL: \u201c\u00c7ekum\u201d kal\u0131nba\u011f\u0131rsa\u011f\u0131n ba\u015flang\u0131\u00e7 b\u00f6l\u00fcm\u00fcn\u00fc olu\u015fturmaktad\u0131r. Kar\u0131n \u00f6n duvar\u0131ndaki izd\u00fc\u015f\u00fcm\u00fc \u201csa\u011f iliak\u201d b\u00f6lgeye uymaktad\u0131r. Y\u00fcksekli\u011fi yakla\u015f\u0131k 6 cm geni\u015fli\u011fi ise 7 cm olan \u00e7ekum, \u00fcstte \u00e7\u0131kan kolonla birle\u015fmektedir. \u00c7ekumun arka b\u00f6l\u00fcm\u00fcne inceba\u011f\u0131rsa\u011f\u0131n \u201cileum\u201d b\u00f6l\u00fcm\u00fc ve \u201capendiks vermiformis\u201d birer delik arac\u0131l\u0131\u011f\u0131yla a\u00e7\u0131lmaktad\u0131rlar. \u00c7ekum, hemen hemen t\u00fcm\u00fcyle peritonla \u00f6rt\u00fcl\u00fcd\u00fcr ve az da olsa hareketlidir. \u0130nceba\u011f\u0131rsa\u011f\u0131n son b\u00f6l\u00fcm\u00fc olan \u201cileum\u201d, kal\u0131nba\u011f\u0131rsa\u011f\u0131n \u201c\u00e7ekum\u201d b\u00f6l\u00fcm\u00fcne a\u00e7\u0131lmaktad\u0131r. \u00c7ekumun arka duvar\u0131nda \u201cileo\u00e7ekal delik\u201d denilen bir delik olu\u015fturan ileum, burada ayn\u0131 zamanda iki dudakl\u0131 bir kapak\u00e7\u0131kta olu\u015fturmaktad\u0131r. Bu kapak\u00e7\u0131\u011fa \u201cileo\u00e7ekal valv\u00fcl\u201d denir. \u0130leo\u00e7ekal valv\u00fcl ba\u011f\u0131rsak dokusunun kendi \u00fczerinde bir kez k\u0131vr\u0131lmas\u0131yla olu\u015fmaktad\u0131r. Yap\u0131s\u0131ndaki d\u00fcz kaslar \u201csfinkter\u201d (b\u00fczgen) g\u00f6revini g\u00f6rmektedir. \u0130leo\u00e7ekal valv\u00fcl, inceba\u011f\u0131rsaktan kal\u0131nba\u011f\u0131rsa\u011fa olan ak\u0131\u015f\u0131n daima tek y\u00f6nl\u00fc olmas\u0131na katk\u0131da bulunan \u00f6nemli bir olu\u015fumdur. <\/p>\n
APEND\u0130KS VERM\u0130FORM\u0130S: \u201cApendiks vermiformis\u201d halk aras\u0131nda ve k\u0131saca yanl\u0131\u015f olarak \u201capandisit\u201d diye bilinmektedir. Oysa \u201capandisit\u201d apendiks vermiformisin iltihaplanmas\u0131 durumuna verilen add\u0131r. Apendiks vermiformis, 2-20 cm boyunda olabilen bir ba\u011f\u0131rsak par\u00e7as\u0131d\u0131r ve \u00e7ekumun arka y\u00fcz\u00fcne a\u00e7\u0131lmaktad\u0131r. \u201cMezoapendiks\u201d denilen bir periton yapra\u011f\u0131 arac\u0131l\u0131\u011f\u0131yla ileumun mezenterine as\u0131lm\u0131\u015ft\u0131r. Apendiks vemiformisi besleyen atardamar, mezoapendiksin i\u00e7inde yol alarak organa ula\u015fmaktad\u0131r. Kal\u0131nba\u011f\u0131rsa\u011f\u0131n d\u0131\u015f y\u00fcz\u00fcnde bulunan \u201ctenia koli\u201d denilen \u00fc\u00e7 bant, apendiks vermiformisin \u00e7ekumla birle\u015fti\u011fi noktadan ba\u015flamaktad\u0131rlar. <\/p>\n
KOLON: Kal\u0131nba\u011f\u0131rsa\u011f\u0131n \u201ckolon\u201d denilen b\u00f6l\u00fcm\u00fc \u201c\u00e7\u0131kan kolon\u201d, \u201ctransvers kolon\u201d, \u201cinen kolon\u201d ve \u201csigmoid kolon\u201d olmak \u00fczere d\u00f6rt b\u00f6l\u00fcmden olu\u015fur. \u00c7\u0131kan kolon 15 cm uzunlu\u011fundad\u0131r. Ba\u015flang\u0131c\u0131 \u00e7ekumla a\u011f\u0131zla\u015fm\u0131\u015ft\u0131r. \u00c7\u0131kan kolonun kar\u0131n i\u00e7indeki kar\u0131n \u00f6n duvar\u0131ndaki izd\u00fc\u015f\u00fcm\u00fc s\u0131ras\u0131yla \u015fu b\u00f6lgelerden ge\u00e7mektedir: En altta ba\u015flang\u0131\u00e7 b\u00f6l\u00fcm\u00fc olan \u201csa\u011f iliak b\u00f6lge\u201d daha sonra \u201csa\u011f lumbal (bel) b\u00f6lge\u201d. Sa\u011f lumbal b\u00f6lgede, karaci\u011ferin alt y\u00fcz\u00fcn\u00fcn hemen alt\u0131nda bulunan bir yerden \u00e7\u0131kan kolon sola do\u011fru bir dirsek yapmaktad\u0131r. Bu dirse\u011fe \u201cfleksura kolika dekstra\u201d denir.<\/p>\n
Kolonun ikinci par\u00e7as\u0131 olan \u201ctransvers kolon\u201d (yatay kolon) yakla\u015f\u0131k olarak 50 cm uzunlu\u011fundad\u0131r. Sa\u011f lumbal b\u00f6lgede \u201cfleksura kolika dekstra\u201ddan ba\u015flar ve a\u00e7\u0131kl\u0131\u011f\u0131 yukar\u0131ya bakan bir e\u011fiklik yaparak sol hipokondriak b\u00f6lgeye ula\u015f\u0131r. Transvers kolon, sol hipokondriak b\u00f6lgede a\u015fa\u011f\u0131ya y\u00f6nelik bir dirsek yapmaktad\u0131r. Bu dirse\u011fe \u201cfleksura kolika sinistra\u201d denir. Transvers kolonun sa\u011f ucunun arka y\u00fcz\u00fc peritonla \u00f6rt\u00fcl\u00fc de\u011fildir. Bu b\u00f6lge, pankreas ba\u015f\u0131 ve duodenumun inen par\u00e7as\u0131yla kom\u015fudur. Bir ba\u011f ile onlara ba\u011flanm\u0131\u015ft\u0131r. <\/p>\n
Kolonun \u00fc\u00e7\u00fcnc\u00fc par\u00e7as\u0131na \u201cinen kolon\u201d denir. Bu b\u00f6l\u00fcm yakla\u015f\u0131k 25 cm uzunlu\u011fundad\u0131r. \u0130nen kolon \u201cfleksura kolika sinistra\u201ddan ba\u015flar, sol hipokondriak, sol lumbal ve sol iliak b\u00f6lgelerini ge\u00e7erek a\u015fa\u011f\u0131da k\u00fc\u00e7\u00fck pelvise gelir. Burada kolonun son b\u00f6l\u00fcm\u00fc olan \u201csigmoid kolon\u201dla birle\u015fir. Fleksura kolika sinistra \u201cfreniko kolik ba\u011f\u201d denilen bir ba\u011f arac\u0131l\u0131\u011f\u0131yla diyafragmaya adeta as\u0131lm\u0131\u015ft\u0131r. <\/p>\n
Kolunun son b\u00f6l\u00fcm\u00fcn\u00fc olu\u015fturan \u201csigmoid kolon\u201d 40 cm boyundad\u0131r ve k\u00fc\u00e7\u00fck pelvisin i\u00e7ine yerle\u015fmi\u015ftir. \u00dcst ucu inen kolonla, alt ucu da rektumla birle\u015fmektedir. Sigmoid kolon \u00fc\u00e7 b\u00f6l\u00fcmden kurulmu\u015ftur. \u0130lk b\u00f6l\u00fcm\u00fc k\u00fc\u00e7\u00fck pelvis i\u00e7inde yukar\u0131dan a\u015fa\u011f\u0131ya iner. \u0130kinci b\u00f6l\u00fcm\u00fc dirsek yaparak pelvis bo\u015flu\u011funu kabaca enlemesine kateder. Bu gidi\u015fi s\u0131ras\u0131nda, erkeklerde rektumla mesane, kad\u0131nlar da ise rahim (uterus) aras\u0131ndad\u0131r. \u00dc\u00e7\u00fcnc\u00fc b\u00f6l\u00fcm\u00fc ise yeniden k\u0131vr\u0131larak orta hatta, rektuma do\u011fru y\u00f6nelir ve onunla birle\u015fir. Sigmoid kolonun t\u00fcm\u00fc peritonla \u00f6rt\u00fclm\u00fc\u015ft\u00fcr. <\/p>\n
REKTUM: Rektum, kal\u0131nba\u011f\u0131rsa\u011f\u0131n \u00fc\u00e7\u00fcnc\u00fc b\u00f6l\u00fcm\u00fcn\u00fc olu\u015fturmaktad\u0131r. Uzunlu\u011fu yakla\u015f\u0131k olarak 12 cm kadard\u0131r. Orta dikey hat \u00fczerinde, yukar\u0131da sigmoid kolonla a\u015fa\u011f\u0131da ise anusla birle\u015fir. Anusla rektumun birle\u015ftikleri d\u00fczey koksig kemi\u011finin ucunun 3 cm kadar \u00f6n\u00fcne rastlamaktad\u0131r. Rektumun geni\u015fli\u011fi ba\u015flang\u0131\u00e7 b\u00f6lgesinde 4 cm kadard\u0131r. Ancak anusa yakla\u015ft\u0131\u011f\u0131nda geni\u015flemektedir. Geni\u015flemi\u015f olan bu rektum b\u00f6l\u00fcm\u00fcne \u201campula rekti\u201d denir. Rektum bo\u015flu\u011funa do\u011fru ba\u015fl\u0131ca d\u00f6rt \u00e7\u0131k\u0131nt\u0131n\u0131n uzand\u0131\u011f\u0131 g\u00f6r\u00fcl\u00fcr. \u201cYatay \u00e7\u0131k\u0131nt\u0131lar\u201d (transvers fold, huston valv\u00fclleri) denilen bu \u00e7\u0131k\u0131nt\u0131lar mukoza tabakas\u0131 ve kas liflerinden ya\u011f\u0131lm\u0131\u015flard\u0131r. Bunlardan ilki rektumun ba\u015flang\u0131\u00e7 b\u00f6l\u00fcm\u00fcne yak\u0131ndad\u0131r. Genellikle yar\u0131may bi\u00e7iminde, sa\u011fda ve solda bulunabilir. \u0130kincisi \u201campula rekti\u201dnin hemen \u00fczerinde bulunmaktad\u0131r ve rektumun \u00f6n ve sa\u011f y\u00fczlerinden kaynaklan\u0131r. \u00dc\u00e7\u00fcnc\u00fcs\u00fc bir \u00f6ncekinin 2.5 cm alt\u0131nda bulunmaktad\u0131r ve rektumun sol yan taraf\u0131ndan kaynaklanmaktad\u0131r. Rektumda tenia koli ve periton bulunmaz. Rektum i\u015flev bak\u0131m\u0131ndan iki b\u00f6lgeye ayr\u0131lmaktad\u0131r. Bunlardan ilki ortadaki yatay \u00e7\u0131k\u0131nt\u0131n\u0131n \u00fczerinde, di\u011feri ise alt\u0131nda kalmaktad\u0131r. \u00dcstteki b\u00f6l\u00fcm\u00fcn i\u00e7ine d\u0131\u015fk\u0131 birikir. Biriken d\u0131\u015fk\u0131 belli bir hacime ula\u015ft\u0131\u011f\u0131nda, rektumu gerip d\u0131\u015fk\u0131lama hissine yol a\u00e7ar. Alt b\u00f6l\u00fcm normalde bo\u015ftur. Ancak m\u00fczmin kab\u0131zlarda bu b\u00f6lge d\u0131\u015fk\u0131yla dolu olabilir. <\/p>\n
Rektumun \u00f6n y\u00fcz\u00fc erkeklerde mesane, prostat, vezika seminalis, \u00fcreterlerin son b\u00f6l\u00fcm\u00fc ve duktus deferensle kom\u015fudur. Kad\u0131nlarda ise rahim ve vaginayla kom\u015fudur. <\/p>\n
ANUS: Anus yakla\u015f\u0131k olarak 4 cm uzunlu\u011fundad\u0131r. \u00dcst ucuyla rektuma ba\u011flanm\u0131\u015ft\u0131r. 1.5 cm\u2019lik \u00fcst b\u00f6l\u00fcm\u00fcnde mukoza tabakas\u0131 anusun bo\u015flu\u011funa do\u011fru 6-9 tane uzunlamas\u0131na \u00e7\u0131k\u0131nt\u0131 yapmaktad\u0131r. Bu \u00e7\u0131k\u0131nt\u0131lara \u201canal kolumn\u201d denir. Her bir kolumnun i\u00e7inde anusa gelen birer atar ve toplardamar bulunmaktad\u0131r. Bu toplardamarlar\u0131n varisle\u015fmesine \u201chemoroid\u201d (basur) denilmektedir. Anal kolumnlar, alt u\u00e7lar\u0131 aras\u0131nda bulunan k\u00fc\u00e7\u00fck kapak\u00e7\u0131klar arac\u0131l\u0131\u011f\u0131yla birbirleriyle ba\u011flant\u0131l\u0131 haldedirler. Bu ba\u011flant\u0131lara \u201canus valv\u00fclleri\u201d denir. Bu kapak\u00e7\u0131klarla anus duvar\u0131 aras\u0131nda k\u00fc\u00e7\u00fck bo\u015fluklar kalmaktad\u0131r. Bu bo\u015fluklara \u201canus sin\u00fcsleri\u201d denir. Bu sin\u00fcsler i\u00e7inde d\u0131\u015fk\u0131n\u0131n birikmesiyle, buralarda enfeksiyonlar geli\u015febilir. Anus valv\u00fclleri, anusun i\u00e7 y\u00fcz\u00fcnde bir hat \u00fczerinde dizilmi\u015flerdir. Bu hatta \u201clinea pektinea\u201d denir.<\/p>\n
Anusun geri kalan b\u00f6l\u00fcm\u00fc linea pektineadan \u00f6tededir. Anusun s\u00f6z\u00fcn\u00fc etti\u011fimiz bu son b\u00f6l\u00fcm\u00fcn\u00fcn i\u00e7 y\u00fcz\u00fc \u00e7ok katl\u0131 keratinle\u015fmeyen epitelle kapl\u0131d\u0131r. <\/p>\n
Anusun iki tane b\u00fcz\u00fcc\u00fc kas\u0131 vard\u0131r. Bunlardan \u201ci\u00e7 sfinkter\u201d ba\u011f\u0131rsak kanal\u0131 boyunca bulunan d\u00fcz kas liflerinin, bu b\u00f6lgedekilerin \u00e7o\u011falmalar\u0131yla olu\u015fmu\u015ftur. \u0130\u00e7 sfinkter d\u00fcz kas liflerinden kurulmu\u015ftur ve istem d\u0131\u015f\u0131 \u00e7al\u0131\u015f\u0131r. Anusun ancak \u00be \u00fcst b\u00f6l\u00fcm\u00fc i\u00e7 sfinkter ile sar\u0131lm\u0131\u015ft\u0131r. Anusun ikinci sfinkterine \u201cd\u0131\u015f sfinkter\u201d denilmektedir. D\u0131\u015f sfinkter \u00e7izgili kas liflerinden olu\u015fmu\u015ftur. \u0130stemli olarak kontrol edilebilir ve anusun b\u00fct\u00fcn uzunlu\u011fu boyunca onu bir halka gibi sarar. D\u0131\u015f sfinkter, d\u0131\u015fk\u0131lama zaman\u0131 d\u0131\u015f\u0131nda, anusu kapal\u0131 tutar. Bu sfinkter kesildi\u011finde ya da ba\u015fka bir nedenle aksad\u0131\u011f\u0131nda, ki\u015fi d\u0131\u015fk\u0131s\u0131n\u0131 tutamaz.<\/p>\n
S\u0130ND\u0130R\u0130M KANALININ DOKUSAL YAPISI: Sindirim kanal\u0131n\u0131n duvar\u0131 b\u00fct\u00fcn uzunlu\u011fu boyunca ba\u015fl\u0131ca d\u00f6rt tabakadan yap\u0131lm\u0131\u015ft\u0131r. Bu tabakalar i\u00e7ten d\u0131\u015fa do\u011fru \u201cmukoza\u201d, \u201csubmukoza\u201d, \u201cmuskularis\u201d ve \u201cadventisia\u201d tabakalar\u0131d\u0131r. Mukoza tabakas\u0131 kendi kendine \u00fc\u00e7 tabakadan olu\u015fmu\u015ftur. Bunlar i\u00e7ten d\u0131\u015fa do\u011fru \u201cepitel\u201d, \u201clamina propria\u201d ve \u201cmuskularis mukoza\u201dd\u0131r. <\/p>\n
\u00d6ZOFAGUSUN DOKUSAL YAPISI: \u00d6zofagusun mukoza tabakas\u0131n\u0131n epitel kat\u0131 \u00e7ok katl\u0131, keratinize olmam\u0131\u015f yass\u0131 epiteldir. Epitel tabakas\u0131n\u0131n alt\u0131ndaki lamina propria, gev\u015fek ba\u011fdokusudur. K\u00fc\u00e7\u00fck kan damarlar\u0131, seyrek bir lenfatik doku ve lenf nod\u00fcllerine sahiptir. Mukoza tabakas\u0131n\u0131n en alt k\u0131sm\u0131 olan \u201cmuskularis mukoza\u201d tabakas\u0131 uzunlamas\u0131na dizilmi\u015f d\u00fcz kas liflerinden olu\u015fmaktad\u0131r. <\/p>\n
Mukozan\u0131n alt\u0131nda bulunan \u201csubmukoza\u201d tabakas\u0131 ya\u011f h\u00fccreleri, b\u00fcy\u00fck kan damarlar\u0131 i\u00e7eren ba\u011fdokusu yap\u0131s\u0131ndad\u0131r. Submukoza tabakas\u0131nda \u00f6zofagus bezlerinin salg\u0131 haz\u0131rlayan b\u00f6l\u00fcmleri de bulunmaktad\u0131r. Haz\u0131rlanan salg\u0131lar k\u0131sa kanalc\u0131klarla mukoza y\u00fczeyine bo\u015falt\u0131l\u0131r. Submukozan\u0131n alt\u0131ndaki \u201cmuskularis\u201d tabakas\u0131 \u00fc\u00e7 kat kastan olu\u015fmu\u015ftur. En i\u00e7 kat \u00f6zofagusu halka bi\u00e7iminde dolanan kaslardan, en d\u0131\u015f kat ise uzunlamas\u0131na seyreden kas liflerinden olu\u015fmu\u015ftur. Ortadaki kat ise e\u011fik seyirli kas liflerinden kurulmu\u015ftur. <\/p>\n
Submukozan\u0131n d\u0131\u015f\u0131nda ise \u00f6zofagusun en d\u0131\u015f kat\u0131 bulunmaktad\u0131r. Bu tabaka ba\u011f dokusu yap\u0131s\u0131ndad\u0131r. \u0130\u00e7inde ya\u011f h\u00fccreleri, damar ve sinirler bulunur. \u00d6zofagus kar\u0131n bo\u015flu\u011funa girdi\u011findeyse adventisia tabakas\u0131n\u0131n yerini peritonun viseral tabakas\u0131 (i\u00e7 organlar\u0131 \u00f6rten tabaka) al\u0131r. Bu tabaka b\u00f6ylelikle \u201cseroza tabakas\u0131\u201d ad\u0131n\u0131 al\u0131r. Halbuki \u00f6zofagusun servikal ve torakal b\u00f6l\u00fcmlerinde seroza tabakas\u0131 bulunmaz. Bu \u00f6zellik sindirim kanal\u0131n\u0131n di\u011fer b\u00f6l\u00fcmlerine g\u00f6re \u00f6nemli bir yap\u0131sal farkl\u0131l\u0131kt\u0131r. <\/p>\n
M\u0130DEN\u0130N DOKUSAL YAPISI: Midenin mukoza tabakas\u0131n\u0131n epitel kat\u0131, tek katl\u0131 mukus salg\u0131layan kolumner epitel h\u00fccrelerinden olu\u015fmu\u015ftur. Epitelin alt\u0131ndaki lamina propria tabakas\u0131, lenf yap\u0131s\u0131ndan \u00e7ok zengindir. \u0130\u00e7inde bir\u00e7ok mukoza bezi i\u00e7eren lamina propria, \u201cfoveola\u201d (gastrik pits) denilen girintilere sahiptir. Foveolalar\u0131n i\u00e7ine mukoza bezleri salg\u0131lar\u0131n\u0131 bo\u015faltmaktad\u0131r. Bu bezler iki tiptir: a) Basit t\u00fcb\u00fcler kardia bezleri; bunlar yaln\u0131z midenin kardia ve \u00f6zofagusun da mideye yak\u0131n b\u00f6l\u00fcmlerinde bulunur. b) Basit t\u00fcb\u00fcler mide bezleri; bu bezler genellikle dallanm\u0131\u015flard\u0131r. Bu bezler 1) Esas h\u00fccreler 2) Parietal h\u00fccreler ve 3) Boyun h\u00fccreleri olmak \u00fczere \u00fc\u00e7 \u00e7e\u015fit salg\u0131 h\u00fccresinden kurulmu\u015flard\u0131r. Mukozan\u0131n \u00fc\u00e7\u00fcnc\u00fc tabaks\u0131 olan \u201cmuskularis mukoza\u201d, i\u00e7te uzunlamas\u0131na d\u0131\u015fta ise halka dizili\u015findeki d\u00fcz kas liflerinden olu\u015fmaktad\u0131r. <\/p>\n
Midenin submukoza ve muskularis tabakalar\u0131 \u00f6zofagustakine benzemektedirler. Seroza tabakas\u0131, peritonun viseral tabakas\u0131 taraf\u0131ndan olu\u015fturulmaktad\u0131r. <\/p>\n
Midenin pilor deli\u011fi etraf\u0131ndaki kaslar say\u0131ca \u00e7o\u011falm\u0131\u015flard\u0131r. Bu kaslar \u00f6zellikle halka dizili\u015f g\u00f6stererek, midenin bu b\u00f6lgesinde sfinkter (b\u00fczgen) olu\u015fturur. Buna \u201cpilor sfinkteri\u201d denilmektedir. <\/p>\n
DUODENUMUN DOKUSAL YAPISI: Duodenumun mukoza tabakas\u0131 ba\u011f\u0131rsa\u011f\u0131n bo\u015flu\u011funa do\u011fru \u201cvillus\u201d denilen \u00e7\u0131k\u0131nt\u0131lar yapmaktad\u0131r. Villuslar aras\u0131ndaki aral\u0131\u011fa ise \u201cvilluslar aras\u0131 aral\u0131k\u201d denilmektedir. Mukoza tabakas\u0131n\u0131n ilk kat\u0131n\u0131 olu\u015fturan epitel kat\u0131 \u201ctek katl\u0131 kolumner epitel h\u00fccreleri\u201dnden ve bunlar\u0131n aras\u0131na sa\u00e7\u0131lm\u0131\u015f \u201cgoblet\u201d h\u00fccrelerinden kurulmu\u015ftur. Kolumner h\u00fccreler, mikrovill\u00fcs denilen eldiven parma\u011f\u0131 bi\u00e7imindeki uzant\u0131lar\u0131 ba\u011f\u0131rsak bo\u015flu\u011funa do\u011fru g\u00f6nderirler. Goblet h\u00fccreleri ise mukus salg\u0131larlar. Epitel kat\u0131n\u0131n alt\u0131nda bulunan lamina propria tabakas\u0131nda \u201cliberk\u00fchn kriptalar\u0131\u201d denilen bezler bulunmaktad\u0131r. Bu bezlerin bir ya da birka\u00e7\u0131 villuslar aras\u0131 aral\u0131\u011f\u0131n dibine a\u00e7\u0131l\u0131rlar. Mukoza tabakas\u0131n\u0131n \u00fc\u00e7\u00fcnc\u00fc kat\u0131 olan \u201cmuskularis mukoza\u201d tabakas\u0131, kar\u0131\u015f\u0131k dizili\u015fli d\u00fcz kas liflerinden olu\u015fmaktad\u0131r. <\/p>\n
Duodenumun submukoza tabakas\u0131nda ba\u011fdokusunun i\u00e7inde \u201cbrunner bezleri\u201d denilen bezler bulunmaktad\u0131r. Brunner bezleri \u201cliberk\u00fchn kriptalar\u0131\u201dna a\u00e7\u0131l\u0131rlar. <\/p>\n
JEJUNUM VE \u0130LEUMUN DOKUSAL YAPISI: Jejunum ve ileum yap\u0131s\u0131 genel hatlar\u0131yla duodenumun yap\u0131s\u0131na benzemektedir. Burada yaln\u0131z farkl\u0131l\u0131klara de\u011finmekle yetinece\u011fiz. Lamina propriaya yerle\u015fmi\u015f olan \u201cliberk\u00fchn bezleri\u201d ndeki basit salg\u0131 h\u00fccrelerine, iki yeni tip h\u00fccrede eklenmi\u015ftir. Bunlar \u201cpaneth h\u00fccreleri\u201d ve \u201cargentafin h\u00fccreleri\u201ddir. Lamina propria \u00f6zellikle lenf yap\u0131s\u0131 bak\u0131m\u0131ndan \u00e7ok zengindir. Buradaki 10 ya da daha fazla say\u0131daki lenf nod\u00fcl\u00fc bir araya gelip, \u201cpeyer plaklar\u0131\u201d denilen yap\u0131lar\u0131 olu\u015ftururlar. Duodenumun d\u0131\u015f\u0131nda, ba\u011f\u0131rsa\u011f\u0131n hi\u00e7bir b\u00f6lgesinde \u201cbrunner bezleri\u201dne rastlanmaz. <\/p>\n
KALINBA\u011eIRSAKLARIN DOKUSAL YAPISI: Kal\u0131nba\u011f\u0131rsaklar\u0131n kolon b\u00f6l\u00fcm\u00fc inceba\u011f\u0131rsaklardan baz\u0131 farkl\u0131l\u0131klar g\u00f6stermektedir. Kal\u0131nba\u011f\u0131rsaklar\u0131n mukoza y\u00fczeyinde villuslar kaybolur ve mukoza y\u00fczeyi d\u00fczle\u015fir. Epitel h\u00fccreleri aras\u0131ndaki goblet h\u00fccrelerinin s\u0131kl\u0131\u011f\u0131 da artar. Muskularis tabakas\u0131n\u0131n d\u0131\u015f\u0131nda \u201ctenia koli\u201d denilen \u015ferit bi\u00e7iminde uzanan yap\u0131lar bulunur. <\/p>\n
Kal\u0131nba\u011f\u0131rsa\u011f\u0131n \u201crektum\u201d b\u00f6l\u00fcm\u00fc, temelde kolonlara benzemektedir. Tenyalar\u0131 yoktur. \u0130\u00e7 y\u00fcz\u00fcnde ise mukoza ve submukozan\u0131n birlikte olu\u015fturduklar\u0131 uzunlamas\u0131na seyreden k\u0131vr\u0131mlar bulunur.<\/p>\n
Anus mukozas\u0131 \u201clinea pektinea\u201d hatt\u0131n\u0131n alt\u0131nda \u00e7ok katl\u0131 keratinle\u015fmemi\u015f epitel h\u00fccreleriyle \u00f6rt\u00fclm\u00fc\u015ft\u00fcr. Mukozada zengin bir toplardamar a\u011f\u0131 bulunmaktad\u0131r. Buna \u201ci\u00e7 hemoroidal ven\u00f6z pleksus\u201d denilmektedir. Bu toplardamarlar\u0131n varisle\u015fmesine \u201ci\u00e7 hemoroidler\u201d (basur) denir. <\/p>\n
KARAC\u0130\u011eER ANATOM\u0130S\u0130: Karaci\u011fer insan v\u00fccudundaki en b\u00fcy\u00fck salg\u0131 bezidir. Kar\u0131n bo\u015flu\u011fu i\u00e7ine yerle\u015fmi\u015f olan bu organ\u0131n, kar\u0131n \u00f6n duvar\u0131ndaki izd\u00fc\u015f\u00fcm\u00fcn\u00fc inceledi\u011fimizde, \u015fu b\u00f6lgeleri kaplad\u0131\u011f\u0131n\u0131 g\u00f6r\u00fcr\u00fcz: Sa\u011f hipokondriak b\u00f6lgenin t\u00fcm\u00fc, epigastrium b\u00f6lgesinin b\u00fcy\u00fck b\u00f6l\u00fcm\u00fc ve sol hipokondriak b\u00f6lgenin bir b\u00f6l\u00fcm\u00fc. Karaci\u011ferin normal bir yeti\u015fkindeki a\u011f\u0131rl\u0131\u011f\u0131 1200-1800 gram kadard\u0131r. Canl\u0131 bir insanda bu a\u011f\u0131rl\u0131\u011f\u0131n \u00fcst\u00fcnde bir de organ\u0131n i\u00e7inde dola\u015fmakta olan yakla\u015f\u0131k 850 gram kan eklenmektedir. Karaci\u011ferin \u00fc\u00e7 y\u00fcz\u00fc vard\u0131r. Bunlar 1) \u00dcst y\u00fcz-diyafragma y\u00fcz\u00fc, 2) Arka y\u00fcz-omurga y\u00fcz\u00fc ve 3) Alt y\u00fcz-viseral y\u00fcz. \u00dcst y\u00fcz\u00fc, diyafragma kas\u0131yla kom\u015fuluk yapmaktad\u0131r ve periton zar\u0131yla \u00f6rt\u00fcl\u00fcd\u00fcr. Arka y\u00fcz\u00fcn\u00fcn b\u00fcy\u00fck b\u00f6l\u00fcm\u00fc peritonsuzdur. Omurga ve vena kava inferior ile kom\u015fuluk yapmaktad\u0131r. Alt y\u00fcz\u00fcnde karaci\u011fere ait iki \u00f6nemli yap\u0131 bulunmaktad\u0131r. Bunlardan biri safra kesesi, di\u011feri ise \u201cporta hepatis\u201d denilen olu\u015fumdur. Karaci\u011ferin alt y\u00fczeyi \u00e7e\u015fitli i\u00e7 organlarla kom\u015fuluk g\u00f6stermektedir. Bu organlar \u015funlard\u0131r: Safra kesesi, sa\u011f b\u00f6brek, mide, kolon ve duodenum. <\/p>\n
Karaci\u011ferin \u201csa\u011f\u201d, \u201csol\u201d, \u201calt\u201d ve \u201ckuadratus\u201d olmak \u00fczere d\u00f6rt lobu bulunmaktad\u0131r. <\/p>\n
KARAC\u0130\u011eER\u0130N DOKUSAL YAPISI: \u0130nsan v\u00fccudunun en b\u00fcy\u00fck salg\u0131 bezi olan karaci\u011ferin b\u00fcy\u00fck bir b\u00f6l\u00fcm\u00fc \u201cperiton zar\u0131\u201d ile kaplanm\u0131\u015ft\u0131r. Bu zar\u0131n a) \u201cT\u00fcnika seroza\u201d ve b) \u201cT\u00fcnika fibroza\u201d olmak \u00fczere iki \u00f6nemli tabakas\u0131n bulunmaktad\u0131r. T\u00fcnika fibroza (glisson kaps\u00fcl\u00fc) porta hepatisten i\u00e7eri girer ve karaci\u011feri lobcuklara ay\u0131r\u0131r. Lobcuklar alt\u0131 k\u00f6\u015felidirler. Bu lobcuklar aras\u0131na uzanm\u0131\u015f olan t\u00fcnika fibroza, \u201clobcuklar aras\u0131 kaps\u00fcl\u201d denilen yap\u0131y\u0131 olu\u015fturur. Lobcuklar aras\u0131 kaps\u00fcl lobcuklar\u0131 \u00e7epe\u00e7evre sarm\u0131\u015f olmay\u0131p, yaln\u0131z k\u00f6\u015felerde bulunur. lobcuklar aras\u0131 kaps\u00fcl\u00fcn i\u00e7inden damarlar, sinirler ve safra yollar\u0131 ge\u00e7er. S\u00f6z\u00fcn\u00fc etti\u011fimiz bu lobcuklar aras\u0131 k\u00f6\u015fe b\u00f6lgelerine \u201ckiernan aral\u0131klar\u0131\u201d denilmektedir. <\/p>\n
Alt\u0131gen karaci\u011fer lobcuklar\u0131n\u0131n merkezinde, \u201cvena sentralis\u201d denilen bir toplardamar bulunmaktad\u0131r. Bu merkezden lobcu\u011fun kenarlar\u0131na do\u011fru \u0131\u015f\u0131n bi\u00e7iminde \u201cremac plaklar\u0131\u201d denilen olu\u015fumlar uzanmaktad\u0131r. Remac plaklar\u0131 s\u0131rt s\u0131rta vermi\u015f olan karaci\u011fer h\u00fccreleri dizilerinden kurulmu\u015flard\u0131r. <\/p>\n
Remac plaklar\u0131n\u0131n aras\u0131nda i\u00e7inde toplardamar kan\u0131n\u0131n dola\u015ft\u0131\u011f\u0131 \u201cven sin\u00fczoidleri\u201d denilen olu\u015fumlar bulunmaktad\u0131r. <\/p>\n
Vena porta ve arteria hepatika propria karaci\u011fere girdikten sonra \u00e7ok say\u0131da dallara b\u00f6l\u00fcn\u00fcrler. Bu dallar kiernan aral\u0131klar\u0131na geldikten sonra lobcuklar\u0131n i\u00e7ine, \u201cremac plaklar\u0131n\u0131n\u201d aras\u0131na do\u011fru uzan\u0131rlar. Lobcuklar\u0131n i\u00e7ine girmi\u015f olan bu dallar birle\u015fip, yukar\u0131da s\u00f6z\u00fcn\u00fc etti\u011fimiz ven sin\u00fczoidlerini olu\u015ftururlar. Vena porta, sindirim kanal\u0131ndan emilen besin maddelerini i\u00e7inde ta\u015f\u0131yan \u00f6zel bir toplardamar a\u011f\u0131n\u0131n kan\u0131n\u0131 ta\u015f\u0131maktad\u0131r. Arteria hepatika propria ise bilinen atardamar kan\u0131d\u0131r. O halde bu damarlar\u0131n uzant\u0131lar\u0131n\u0131n karaci\u011fer lobcuklar\u0131 i\u00e7inde birle\u015fmeleriyla olu\u015fan ven sin\u00fczoidlerinin i\u00e7inde dola\u015fmakta olan kan, tam anlam\u0131yla toplardamar kan\u0131 de\u011fil, daha de\u011fi\u015fik bir kimyasal yap\u0131ya sahip olan kand\u0131r. Fakat bu kan i\u00e7in kabaca, toplardamar kan\u0131 demi\u015f oldu\u011fumuzda b\u00fcy\u00fck bir yanl\u0131\u015f yapm\u0131\u015f olmay\u0131z. Ven sin\u00fczoidlerinin duvar\u0131n\u0131, b\u00fct\u00fcn dola\u015f\u0131m sisteminin duvar\u0131n\u0131n i\u00e7 y\u00fcz\u00fcn\u00fc \u00f6rtmekte olan \u201cendotel\u201d denilen tek katl\u0131 yass\u0131 epitel h\u00fccreler olu\u015fturmaktad\u0131rlar. Ven sin\u00fczoidleri ile remac plaklar\u0131 ars\u0131nda kalan aral\u0131\u011fa ise \u201cdisse aral\u0131\u011f\u0131\u201d denilmektedir. Disse aral\u0131klar\u0131n\u0131n ince lenf damarlar\u0131 bulunmaktad\u0131r.
\nRemac plaklar\u0131 olu\u015fturan karaci\u011fer h\u00fccreleri hepatosit aras\u0131nda \u201ckupfer y\u0131ld\u0131z h\u00fccreleri\u201d denilen h\u00fccreler de bulunmaktad\u0131r. Bu h\u00fccreler fogositoz \u00f6zelli\u011fine sahiptirler ve \u201cretik\u00fcloendotalial sistemi\u201dne aittirler. Kupfer y\u0131ld\u0131z h\u00fccreleri makrofojdurlar. Her bir remac pla\u011f\u0131n\u0131 olu\u015fturan karaci\u011fer h\u00fccrelerinin birbirine bakan kom\u015fu y\u00fczleri aras\u0131nda bir aral\u0131k bulunmaktad\u0131r. Bu aral\u0131\u011fa \u201csafra kanalc\u0131klar\u0131\u201d denilmektedir. \u00c7\u00fcnk\u00fc karaci\u011fer h\u00fccreleri taraf\u0131ndan salg\u0131lanan safra, bu kanalc\u0131klar i\u00e7ine salg\u0131lanmaktad\u0131r. Safra kanalc\u0131klar\u0131n\u0131n duvar\u0131 karaci\u011fer h\u00fccreleri taraf\u0131ndan olu\u015fturulmaktad\u0131r. Safra kanalc\u0131klar\u0131, karaci\u011fer i\u00e7i safra kanallar\u0131na d\u00f6k\u00fcl\u00fcrler. Bu kanallar ise sonunda sa\u011f ve sol \u201chepatik duktus\u201d denilen iki b\u00fcy\u00fck safra kanal\u0131n\u0131 olu\u015ftururlar. <\/p>\n
Remac plaklar\u0131 aras\u0131ndaki ven sin\u00fczoidleri karaci\u011fer lobcu\u011funun merkezindeki \u201cvena sentralis\u201de d\u00f6k\u00fcl\u00fcrler. Bir\u00e7ok vena sentralis ise birle\u015ferek, \u201cvena sublobularis\u201d denilen toplardamarlar\u0131 olu\u015ftururlar. Bu damarlar\u0131nda birle\u015fmesiyle \u201cvena hepatika\u201d olu\u015fur. <\/p>\n
Karaci\u011fer i\u00e7indeki bu \u00f6zel kan dola\u015f\u0131m\u0131 g\u00f6z \u00f6n\u00fcne al\u0131nd\u0131\u011f\u0131nda, \u015fu \u00f6zellik g\u00f6ze \u00e7arpar: Sindirim kanal\u0131nda emilen besin maddelerini i\u00e7eren \u201cvena porta\u201d kan\u0131, karaci\u011fere gelip, karaci\u011fer h\u00fccreleri taraf\u0131ndan \u00e7e\u015fitli ama\u00e7larla denetlenip, i\u015flendikten sonra vena kava inferiora, yani toplardamar sistemine bo\u015falt\u0131l\u0131r. <\/p>\n
SAFRA KESES\u0130 VE SAFRA YOLLARI: Karaci\u011fer h\u00fccrelerinde \u00fcretilip \u201cremac plaklar\u0131\u201d i\u00e7indeki safra kanalc\u0131klar\u0131 i\u00e7ine salg\u0131lanan safra, daha sonra \u201ckaraci\u011fer i\u00e7i safra kanallar\u0131\u201dna ula\u015f\u0131r. Karaci\u011fer i\u00e7i safra kanallar\u0131 birbirleriyle birle\u015ferek iki b\u00fcy\u00fck safra kanal\u0131 olu\u015fturur. Bunlar \u201csa\u011f hepatik duktus\u201d ve \u201csol hepatik duktus\u201dtur. Sa\u011f ve sol hepatik duktuslar birle\u015ferek, karaci\u011feri porta hepatisten tek bir safra yolu olarak terk ederler. Bu yeni kanala \u201cortak hepatik duktus\u201d denir. Buna da \u201cduktus sistukus\u201d denilen bir safra yolu a\u00e7\u0131l\u0131r. Bu kanal safra kesesini orta hepatik duktusa ba\u011flar. Duktus sistikus ile ortak hepatik duktusun birle\u015fmesiyle olu\u015fan yeni kanala ise \u201csafra kanal\u0131\u201d denilmektedir. Safra kanal\u0131 ise \u201cpankreas kanal\u0131\u201d ile birle\u015ferek \u201chepatopankreatik ampula\u201d denilen yap\u0131y\u0131 olu\u015fturur. Bu yap\u0131, dudenumun inen b\u00f6l\u00fcm\u00fcn\u00fcn arka duvar\u0131na pilordan 8-10 cm\u2019lik bir uzakl\u0131kta a\u00e7\u0131l\u0131r. Burada \u201cb\u00fcy\u00fck duodenal papilla\u201d denilen bir kabart\u0131 yapar. <\/p>\n
Safra kesesi 7-10 cm uzunlu\u011fundad\u0131r ve en geni\u015f yeri 3 cm kadard\u0131r. 30-50 ml kadar safra depolayabilir. Safra kesesi karaci\u011ferin alt y\u00fcz\u00fcne yerle\u015fmi\u015ftir ve \u201cfundus\u201d, \u201cg\u00f6vde\u201d ve \u201cboyun\u201d olmak \u00fczere \u00fc\u00e7 b\u00f6l\u00fcm\u00fc vard\u0131r. \u00dcst y\u00fcz\u00fc karaci\u011fere ba\u011fdokusu arac\u0131l\u0131\u011f\u0131yla ba\u011flanm\u0131\u015ft\u0131r. Alt y\u00fcz\u00fc ise peritonla \u00f6rt\u00fclm\u00fc\u015ft\u00fcr; bu, karaci\u011feri \u00f6rten peritondan uzanm\u0131\u015ft\u0131r. <\/p>\n
SAFRA KESES\u0130 VE SAFRA YOLLARININ DOKUSAL YAPISI: Safra kesesinin duvar\u0131 \u00fc\u00e7 tabakadan olu\u015fur. Bunlar a) Mukoza b) Fibrom\u00fcsk\u00fcler tabaka c) Seroza tabakas\u0131 ile sar\u0131l\u0131 \u201cperim\u00fcsk\u00fcler ba\u011fdokusu\u201ddur. <\/p>\n
Mukoza tabakas\u0131 epitel ve bunun alt\u0131ndaki \u201clamina propria\u201d tabakas\u0131nda olu\u015fmaktad\u0131r. Epitel, tek katl\u0131 kolumnar epitel h\u00fccreleridir. Lamina propria ise gev\u015fek ba\u011fdokusu yap\u0131s\u0131ndad\u0131r ve i\u00e7inde lenf damarlar\u0131 bulunur. <\/p>\n
Fibrom\u00fcsk\u00fcler tabaka halka dizili\u015fli d\u00fcz kas liflerinden, ba\u011fdokusunun elastik liflerinden zengin bir gev\u015fek ba\u011fdokusudur. Bu tabaka ince kan damarlar\u0131nda bulunmaktad\u0131r. <\/p>\n
Perim\u00fcsk\u00fcler ba\u011fdokusu tabakas\u0131 da gev\u015fek ba\u011fdokusu yap\u0131s\u0131ndad\u0131r. Bu tabaka en d\u0131\u015ftan seroza ile kaplanm\u0131\u015f durumdad\u0131r, i\u00e7inde kan damarlar\u0131, lenf damarlar\u0131 ve sinir lifleri bulunur. Yukar\u0131da s\u00f6z\u00fcn\u00fc etti\u011fimiz doku tabakalar\u0131, karaci\u011fer d\u0131\u015f\u0131 safra yollar\u0131nda da aynen bulunmaktad\u0131r. Tek fark, \u201chepatopankreatik ampula\u201d b\u00f6lgesinde fibrom\u00fcsk\u00fcler tabakadaki d\u00fcz kas lifleri say\u0131ca \u00e7o\u011falarak, bir b\u00fczgen olu\u015fturmaktad\u0131rlar. Bunun ad\u0131 \u201coddi sfinkter\u201ddir. Oddi sfinkteri gev\u015fedi\u011finde safra ve pankreas salg\u0131s\u0131 duodenum bo\u015flu\u011funa akar. <\/p>\n
PANKREAS: Pankreas, 12-15 cm uzunlu\u011funda 60-80 gram a\u011f\u0131rl\u0131\u011f\u0131nda, hem i\u00e7 salg\u0131 hem de d\u0131\u015f salg\u0131 i\u015flevini y\u00fcklenen bir bezdir. Midenin arkas\u0131nda, duodenumdan dala\u011fa kadar uzan\u0131r. Ba\u015f, boyun, g\u00f6vde ve kuyruk olmak \u00fczere d\u00f6rt b\u00f6l\u00fcmden olu\u015fur. <\/p>\n
Pankreas ba\u015f\u0131 dudenumun olu\u015fturdu\u011fu kavis i\u00e7ine yerle\u015fmi\u015ftir. Pankreas boynunun \u00f6n y\u00fcz\u00fc peritonla kapl\u0131d\u0131r. Pankreas g\u00f6vdesinin de \u00f6n y\u00fcz\u00fc peritonla kapl\u0131d\u0131r. Pankreas kuyru\u011fu, dalak ile sol b\u00f6brek aras\u0131nda bulunan \u201clienorenal ba\u011f\u201d aras\u0131na yerle\u015fmi\u015ftir. Pankreas\u0131n i\u00e7inde, bu organ\u0131 kuyruktan ba\u015fa kadar, boydan boya kat eden bir kanal bulunmaktad\u0131r. Bu kanala \u201cduktus pankreatikus\u201d denilmektedir. Duktus pankreatikus, pankreas\u0131, pankreas ba\u015f\u0131ndan terk ederek biraz ileride safra kanal\u0131 ile birle\u015ferek \u201chepatopankreatik ampula\u201dy\u0131 olu\u015fturur ve duodenumun inen b\u00f6l\u00fcm\u00fcn\u00fcn arka duvar\u0131na a\u00e7\u0131l\u0131r. Duodenumun bu noktas\u0131nda \u201cmaj\u00f6r duodenal papilla\u201d denilen bir kabart\u0131 bulunmaktad\u0131r. Bazen duktus pankreatikusa paralel olarak seyreden, ondan daha k\u0131sa bir kanal daha bulunmaktad\u0131r. Bu ikinci kanala ise \u201caksesuar duktus pankreatikus\u201d denilmektedir. Bu ikinci kanal ilki ile birle\u015fici bir dala sahiptir ve ondan ayr\u0131 olarak dudenumun arka duvar\u0131nda, maj\u00f6r deodenal papillan\u0131n 1-2 cm \u00fczerindeki bir noktaya, \u201cmin\u00f6r duodenal papilla\u201d denilen bir kabart\u0131ya yol a\u00e7arak a\u00e7\u0131l\u0131r. Aksesuar duktus pankreatikusa \u201csantorini kanal\u0131\u201d da denilmektedir. Duktus pankreatikus ve santorini kanallar\u0131 pankreas\u0131n haz\u0131rlad\u0131\u011f\u0131 d\u0131\u015f salg\u0131y\u0131 dudenuma bo\u015falt\u0131rlar. <\/p>\n
PANKREASIN DOKUSAL YAPISI: Bilindi\u011fi gibi, pankreas, hem i\u00e7 salg\u0131 hem de d\u0131\u015f salg\u0131 i\u015flevini \u00fcstlenen bir bezdir. Organ\u0131n dokusal yap\u0131s\u0131 incelendi\u011finde, en b\u00fcy\u00fck b\u00f6l\u00fcm\u00fcn d\u0131\u015f salg\u0131 i\u015flevini y\u00fcr\u00fcten h\u00fccre ve \u00f6\u011felerden olu\u015ftu\u011fu, i\u00e7 salg\u0131 \u00f6\u011felerinin ise d\u0131\u015f salg\u0131 \u00f6\u011felerinin i\u00e7inde da\u011f\u0131lm\u0131\u015f olarak bulundu\u011fu g\u00f6r\u00fcl\u00fcr. Pankreas\u0131n bu yap\u0131s\u0131 g\u00f6z \u00f6n\u00fcne al\u0131narak onu d\u0131\u015f salg\u0131 b\u00f6l\u00fcm\u00fc ve i\u00e7 salg\u0131 b\u00f6l\u00fcm\u00fc olarak iki b\u00f6l\u00fcmde inceleyece\u011fiz.<\/p>\n
D\u0131\u015f salg\u0131 b\u00f6l\u00fcm\u00fc: Pankreas\u0131n bu b\u00f6l\u00fcm\u00fc lobcuklu bir yap\u0131 g\u00f6stermektedir. Lobcuklar ise \u201casin\u00fcs\u201d denilen k\u00fc\u00e7\u00fck, fakat as\u0131l salg\u0131 \u00f6\u011felerinden olu\u015fmu\u015flard\u0131r. Lobcuklar ve asin\u00fcsler aras\u0131nda ba\u011fdokusu bulunmaktad\u0131r. Asin\u00fcslerin duvarlar\u0131 pankreas\u0131n d\u0131\u015f salg\u0131s\u0131n\u0131 \u00fcreten epitel h\u00fccrelerinden yap\u0131lm\u0131\u015ft\u0131r. Kabaca keselere benzetebilece\u011fimiz asin\u00fcsler i\u00e7lerine biriken salg\u0131y\u0131 lobcuklar i\u00e7i kanalc\u0131klar arac\u0131l\u0131\u011f\u0131yla lobcuklar aras\u0131 kanallara bo\u015falt\u0131rlar. Lobcuklar aras\u0131 kanallar ise pankreas\u0131n as\u0131l iki b\u00fcy\u00fck kanal\u0131na a\u00e7\u0131l\u0131rlar. Pankreas\u0131n bu yap\u0131s\u0131nda \u201carjentafin k\u00fccreler\u201de rastlanmaktad\u0131r. <\/p>\n
\u0130\u00e7 salg\u0131 b\u00f6l\u00fcm\u00fc: \u201cLangerhans adac\u0131klar\u0131\u201d \u00f6zel h\u00fccre ve damar k\u00fcmeleri taraf\u0131ndan olu\u015fturulmu\u015ftur. \u0130nsan pankreas\u0131nda bir milyondan fazla bulunurlar. Langerhans adac\u0131klar\u0131 pankreas\u0131n d\u0131\u015f salg\u0131 yap\u0131s\u0131n\u0131n i\u00e7inde, ger\u00e7ekten adac\u0131klar olu\u015fturacak \u015fekilde da\u011f\u0131lm\u0131\u015ft\u0131r. Bilindi\u011fi gibi i\u00e7 salg\u0131 b\u00f6l\u00fcm\u00fc, ba\u015fl\u0131ca ins\u00fclin hormonu salg\u0131lamaktad\u0131r. Langerhans adac\u0131klar\u0131nda 1) A1, D ya da Alfa1, 2) A2 ya da Alfa 2 ve 3) B ya da Beta olmak \u00fczere \u00fc\u00e7 ana tipte i\u00e7 salg\u0131 h\u00fccresi bulunmaktad\u0131r. Bunlardan ba\u015fka endotel h\u00fccrelerine ve sinir h\u00fccrelerine de rastlanmaktad\u0131r. <\/p>\n
Beta h\u00fccreleri langerhans adac\u0131klar\u0131ndaki h\u00fccrelerin %80\u2019ini olu\u015ftururlar ve ins\u00fclin hormonunu salg\u0131larlar. Alfa 2 h\u00fccreleri \u201cglukagon\u201d adl\u0131 hormonu salg\u0131larlar. Alfa 1 h\u00fccrelerinin serotonin ve penkreatik gastrin hormonu salg\u0131lad\u0131klar\u0131 d\u00fc\u015f\u00fcn\u00fclmekle birlikte, g\u00f6revleri tam olarak bilinmemektedirler.<\/p>\n
Langerhans adac\u0131klar\u0131 i\u00e7inde endotel h\u00fccrelerinin kurmu\u015f olduklar\u0131 yayg\u0131n bir k\u0131lcal damar a\u011f\u0131 bulunmaktad\u0131r. B\u00f6ylece pankreas\u0131n bu b\u00f6l\u00fcmlerinde \u00fcretilen ins\u00fclin, glukagon hormonlar h\u0131zla k\u0131lcal damar kan\u0131na, oradan da v\u00fccudun kan dola\u015f\u0131m\u0131na kat\u0131l\u0131rlar. <\/p>\n
T\u00dcK\u00dcR\u00dcK BEZLER\u0130 VE DOKUSAL YAPILARI: V\u00fccutta \u00fc\u00e7 \u00e7ift t\u00fck\u00fcr\u00fck bezi bulunmaktad\u0131r. Bunlar sa\u011fda ve solda birer tane olmak \u00fczere parotis, sublingual ve submandib\u00fcler t\u00fck\u00fcr\u00fck bezleridir. Parotis adl\u0131 t\u00fck\u00fcr\u00fck bezi, en en b\u00fcy\u00fck olan\u0131d\u0131r. Yakla\u015f\u0131k 25 gram a\u011f\u0131rl\u0131\u011f\u0131ndad\u0131r. Kulak sayvan\u0131 ve d\u0131\u015f kulak yolunun \u00f6n\u00fcnde ve alt\u0131nda, stenkoleidomastoid kas\u0131n\u0131n ise \u00fcst ucunun \u00f6n\u00fcnde bulunur. Masseter kas\u0131n\u0131n d\u0131\u015f y\u00fcz\u00fcnde \u00f6ne do\u011fru ilerler. Parotis bezi bir zar ile kapl\u0131d\u0131r. Parotis bezinin salg\u0131s\u0131 parotis kanal\u0131 denilen bir kanalc\u0131k arac\u0131l\u0131\u011f\u0131yla a\u011f\u0131z bo\u015flu\u011funa ak\u0131t\u0131l\u0131r. Parotis kanal\u0131 yakla\u015f\u0131k olarak 5 cm uzunlu\u011fundad\u0131r ve yana\u011f\u0131n i\u00e7 y\u00fcz\u00fcnde \u00fcst ikinci moler di\u015f hizas\u0131nda a\u011f\u0131z bo\u015flu\u011funa a\u00e7\u0131l\u0131r. <\/p>\n
Sublingual t\u00fck\u00fcr\u00fck bezi a\u011f\u0131z i\u00e7 taban\u0131n\u0131 \u00f6rten mukozan\u0131n hemen alt\u0131nda bulunmaktad\u0131r. Kabaca dilin serbest b\u00f6l\u00fcm\u00fcn\u00fcn alt y\u00fcz\u00fcn\u00fcn a\u011f\u0131z taban\u0131n\u0131 \u00f6rten b\u00f6l\u00fcm\u00fcne kom\u015fuluk yapmaktad\u0131r. En k\u00fc\u00e7\u00fck t\u00fck\u00fcr\u00fck bezi, sublingual t\u00fck\u00fcr\u00fck bezidir. A\u011f\u0131rl\u0131\u011f\u0131 4gr\u2019d\u0131r. 8-20 kadar k\u0131sa kanalc\u0131k arac\u0131l\u0131\u011f\u0131yla \u00fcretti\u011fi t\u00fck\u00fcr\u00fc\u011f\u00fc a\u011f\u0131z taban\u0131na dil alt\u0131na rastlayan bir b\u00f6lgeye bo\u015falt\u0131r. <\/p>\n
Submandib\u00fcler t\u00fck\u00fcr\u00fck bezi, alt \u00e7ene kemi\u011finin g\u00f6vde b\u00f6l\u00fcm\u00fcn\u00fcn i\u00e7 y\u00fcz\u00fcne kom\u015fu olarak yerle\u015fmi\u015ftir. Yakla\u015f\u0131k 5 cm uzunlu\u011fundaki \u201csubmandib\u00fcler kanal\u201d denilen bir kanal arac\u0131l\u0131\u011f\u0131yla organda haz\u0131rlanm\u0131\u015f t\u00fck\u00fcr\u00fck bezinin \u201cfrenulum\u201d (dil ba\u011f\u0131) denilen ba\u011f\u0131n\u0131n iki yan\u0131na, a\u011f\u0131z taban\u0131na d\u00f6k\u00fcl\u00fcr.<\/p>\n
T\u00fck\u00fcr\u00fck bezleri \u201calveol\u201d denilen \u00e7ok say\u0131da k\u00fc\u00e7\u00fck salg\u0131 keseciklerinden, bunlar\u0131n birle\u015fmesiyle kurulmu\u015f lobcuklardan, lobcuklar\u0131n da birle\u015fmesiyle olu\u015fan loblardan ve \u00fcretilmi\u015f olan t\u00fck\u00fcr\u00fc\u011f\u00fc ta\u015f\u0131yan kanalc\u0131klardan kurulmu\u015ftur. T\u00fck\u00fcr\u00fck bezlerinde ba\u015fl\u0131ca iki \u00e7e\u015fit alveol bulunur. bunlardan birine \u201cser\u00f6z alveoller\u201d di\u011ferine ise \u201cm\u00fck\u00f6z alveoller\u201d denilmektedir. M\u00fck\u00f6z alveolleri olu\u015fturan salg\u0131 epitel h\u00fccrelerinden, i\u00e7inde m\u00fcsin maddesi de bulunan olduk\u00e7a yo\u011fun bir salg\u0131 salg\u0131lan\u0131r. Ser\u00f6z alveolleri olu\u015fturan epitel h\u00fccreleri ise yo\u011funlu\u011fu daha az bir salg\u0131 salg\u0131lamaktad\u0131rlar. Parotis bezi yaln\u0131z ser\u00f6z alveollere sahipken, di\u011fer iki t\u00fck\u00fcr\u00fck bezi hem ser\u00f6z hem de m\u00fck\u00f6z alveollere sahiptir. T\u00fck\u00fcr\u00fck bezlerinde haz\u0131rlanan salg\u0131 i\u00e7inde \u201ct\u00fck\u00fcr\u00fck amilaz\u0131\u201d denilen bir enzim de bulunmaktad\u0131r.<\/p>\n
T\u00dcK\u00dcR\u00dcK SALGISI: G\u00fcnde yakla\u015f\u0131k 1500ml t\u00fck\u00fcr\u00fck a\u011f\u0131z i\u00e7inde salg\u0131lanmaktad\u0131r. T\u00fck\u00fcr\u00fc\u011f\u00fcn pH\u2019\u0131 yakla\u015f\u0131k 7\u2019dir. T\u00fck\u00fcr\u00fck i\u00e7inde su, sodyum, klor\u00fcr, kalsiyum, potasyum, bikarbonat, imm\u00fcn globulin A (IgA), albumin, t\u00fck\u00fcr\u00fck amilaz\u0131 ve glikoprotein yap\u0131s\u0131nda olan m\u00fcsin bulunmaktad\u0131r. Ptiyalin, ni\u015fastalar\u0131n sindirilmesinde g\u00f6rev almaktad\u0131r. M\u00fcsin ise a\u011f\u0131z i\u00e7indeki besinlerin kayganla\u015fmas\u0131n\u0131 sa\u011flamaktad\u0131r. T\u00fck\u00fcr\u00fck a\u011f\u0131z i\u00e7ini s\u00fcrekli olarak nemli tutar. Besinlerin i\u00e7indeki baz\u0131 molek\u00fclleri \u00e7\u00f6zerek, bunlar\u0131n tat alma organc\u0131klar\u0131na ula\u015fmalar\u0131n\u0131 sa\u011flar. Yutma i\u015flemini kolayla\u015ft\u0131rd\u0131\u011f\u0131 gibi dil ve dudaklar\u0131n hareketlerini serbestle\u015ftirerek, konu\u015fmay\u0131 da kolayla\u015ft\u0131r\u0131r. Di\u015fleri ve a\u011f\u0131z i\u00e7ini s\u00fcrekli y\u0131kayarak, bunlar\u0131n temiz kalmas\u0131n\u0131 sa\u011flar. pH\u2019\u0131 7 olan t\u00fck\u00fcr\u00fck, kalsiyum ile doymu\u015ftur. Bu nedenle di\u015fler, t\u00fck\u00fcr\u00fc\u011fe do\u011fru kalsiyum kaybetmezler. Ancak t\u00fck\u00fcr\u00fck pH\u2019\u0131 asit tarafa kayd\u0131\u011f\u0131nda, kalsiyum bak\u0131m\u0131ndan doymu\u015flu\u011fu azal\u0131r. Bu durumda di\u015fler t\u00fck\u00fcr\u00fc\u011fe do\u011fru kalsiyum kaybederler. T\u00fck\u00fcr\u00fck salg\u0131s\u0131 sinirsel kontrol alt\u0131ndad\u0131r. Onotom sinir sistemi t\u00fck\u00fcr\u00fck salg\u0131s\u0131n\u0131n denetiminden sorumludur.<\/p>\n
M\u0130DE SALGISI: Mide salg\u0131s\u0131, midenin mukoza tabakas\u0131ndaki h\u00fccrelerin bir i\u015flevidir. Mide mukozas\u0131nda ba\u015fl\u0131ca be\u015f \u00e7e\u015fit h\u00fccre bulunmaktad\u0131r. <\/p>\n
Parietal h\u00fccreler HCI ve intrensek fakt\u00f6r adl\u0131 maddeleri salg\u0131larlar. Esas h\u00fccreler ise pepsin salg\u0131larlar. Tek katl\u0131 kolumner epitel h\u00fccreleri ve boyun h\u00fccreleri ise mukus salg\u0131lamaktad\u0131rlar. Mukus mide duvar\u0131n\u0131, midenin salg\u0131lad\u0131\u011f\u0131 HCI ve pepsinin sindirici etkisinden korur. B\u00f6ylece mide kendi kendisini sindirmekten kurtulmu\u015f olur. Midenin g\u00fcnl\u00fck salg\u0131s\u0131 yakla\u015f\u0131k olarak 3000ml kadard\u0131r. Bu salg\u0131n\u0131n pH\u2019\u0131 ise yakla\u015f\u0131k olarak 1\u2019dir, yani asittir. Mide salg\u0131s\u0131 i\u00e7inde su, sodyum, potasyum, magnezyum, hidrojen, klor, fosfor ve k\u00fck\u00fcrt bile\u015fikleri, pepsin, intrensek fakt\u00f6r, jelatinaz ve mukus bulunmaktad\u0131r. <\/p>\n
Midenin pepsin salg\u0131s\u0131 proteinlerin sindirilmesinde etkilidir, fakat gerekli de\u011fildir. Buna kar\u015f\u0131l\u0131k midenin intrensek fakt\u00f6r salg\u0131s\u0131 B12 vitamini emilimi i\u00e7in kesinlikle gereklidir. Midenin HCI salg\u0131s\u0131 ise demir emiliminde \u00e7ok \u00f6nemli rol oynamaktad\u0131r. <\/p>\n
Midedeki salg\u0131lama olay\u0131, sinirsel ve hormonal olmak \u00fczere ba\u015fl\u0131ca iki mekanizma ile denetlenmektedir. Bunlardan ilkinde, yani sinirsel kontrolde salg\u0131lama i\u00e7in gerekli sinirsel uyar\u0131lar, vagus siniri i\u00e7inde mideye ula\u015fmaktad\u0131r. Kandaki glikoz d\u00fczeyinin d\u00fc\u015fmesi ya da i\u015ftah a\u00e7\u0131c\u0131 besin maddelerini g\u00f6rmek ve d\u00fc\u015f\u00fcnmek, mide salg\u0131s\u0131n\u0131n sinirsel d\u00f6nemini olu\u015fturur. Midenin antrum b\u00f6lgesindeki G-h\u00fccrelerinden kana verilen gastrin adl\u0131 hormon ise, mide salg\u0131s\u0131n\u0131n hormonal mekanizmas\u0131n\u0131 ba\u015flatmaktad\u0131r. Antrum b\u00f6lgesinin besinlerle girilmesi ya da buradaki asitli\u011fn azalmas\u0131 ya da vagus sinirin uyar\u0131lmas\u0131, G-h\u00fccrelerinden gastrin salg\u0131lanmas\u0131na yol a\u00e7ar. Antrum b\u00f6lgesinin asitli\u011finin yeterli d\u00fczeye eri\u015fmesi ya da \u201catropin\u201d, gastrin salg\u0131s\u0131n\u0131 azalt\u0131r. <\/p>\n
PANKREAS SALGISI: Pankreastan her g\u00fcn yakla\u015f\u0131k olarak 1500ml pankreas salg\u0131s\u0131 salg\u0131lanmaktad\u0131r. Pankreas salg\u0131s\u0131n\u0131n pH\u2019\u0131 yakla\u015f\u0131k olarak 8\u2019dir, yani alkalidir. Salg\u0131s\u0131n\u0131n i\u00e7inde su, sodyum, potasyum, kalsiyum, magnezyum, klor, s\u00fclfat, fosfat, albumin, globulin ve sindirim enzimleri bulunmaktad\u0131r. Pankreastan salg\u0131lanan sindirim enzimleri \u015funlard\u0131r: tripsin, kimotripsin, elastaz, karboksipeptidaz, lipaz, esteraz, amilaz, ribon\u00fckleaz, deoksiribon\u00fckleaz, fosfolipaz. <\/p>\n
Pankreas salg\u0131s\u0131, organ\u0131n d\u0131\u015f salg\u0131 b\u00f6l\u00fcm\u00fcn\u00fcn i\u015flevidir. Midenin fundus ve ya antrum b\u00f6l\u00fcm\u00fcn\u00fcn besinlerle gerilmesi, vagus sinirinin uyar\u0131lmas\u0131, duodenum ve jejunumdan salg\u0131lanan \u201csekretin\u201d adl\u0131 hormonlar, pankreas\u0131n salg\u0131lama i\u015flevini uyar\u0131rlar. Duodenuma ge\u00e7mi\u015f olan besinlerin asitli\u011fi ise sekretin salg\u0131s\u0131 i\u00e7in en etkin uyar\u0131c\u0131d\u0131r. <\/p>\n
Duodenum ve jejunumdan salg\u0131lanan \u201ckolesistokinin-pankreozimin\u201d (CCK-PZ) adl\u0131 hormon ise pankreastan, \u00f6zellikle sindirim enzimlerinden zengin bir salg\u0131n\u0131n salg\u0131lanmas\u0131na yol a\u00e7maktad\u0131r. Buna kar\u015f\u0131l\u0131k sekretin, bikarbonat ve s\u0131v\u0131dan zengin bir pankreas salg\u0131s\u0131na yol a\u00e7maktad\u0131r. Vagus sinirinin uyar\u0131lmas\u0131 da CCK-PZ uyar\u0131s\u0131na benzer bir etkiye sahiptir.<\/p>\n
Pankreastan salg\u0131lanan tripsin, kimotripsin, elastaz ve karboksipeptidaz proteinler ve polipeptidler \u00fczerinde sindirici etkiye sahiptirler. Amilaz ni\u015fasta \u00fczerinde etkilidir. Lipaz trigliserid yap\u0131s\u0131ndaki, esteraz ise kolesterol yap\u0131s\u0131ndaki ya\u011flar \u00fczerinde sindirici etkiye sahiptir. Fosfolipaz ise lesitin \u00fczerinde etkilidir.<\/p>\n
SAFRA SALGISI: Safra karaci\u011fer h\u00fccreleri taraf\u0131ndan haz\u0131rlan\u0131r ve \u00f6zel kanallardan ge\u00e7erek, fazlas\u0131 safra kesesi i\u00e7inde depolanmak \u00fczere, dudenuma bo\u015falt\u0131l\u0131r. G\u00fcnde yakla\u015f\u0131k 500ml safra salg\u0131lanmaktad\u0131r. Safra salg\u0131s\u0131n\u0131n iki \u00f6nemli fizyolojik etkisi vard\u0131r. Bunlardan ilki safra i\u00e7inde bulunan safra tuzlar\u0131n\u0131n, ya\u011flar\u0131n ba\u011f\u0131rsaklardan emilimlerini sa\u011flamalar\u0131, ikincisi ise safra i\u00e7inde bilirubin ve benzeri maddelerin salg\u0131lan\u0131yor olmas\u0131d\u0131r. <\/p>\n
Safra, karaci\u011fer h\u00fccreleri taraf\u0131ndan s\u00fcrekli olarak safra yollar\u0131na salg\u0131lanmaktad\u0131r. Buna kar\u015f\u0131l\u0131k yaln\u0131z gerekli zamanlarda safra kesesinden salg\u0131lanmaktad\u0131r.<\/p>\n
Safra salg\u0131s\u0131, safra tuzlar\u0131, kolesterol, lesitin, su (%97), bilirubin, sodyum, potasyum, klor\u00fcr, magnezyum ve baz\u0131 inorganik tuzlardan olu\u015fmaktad\u0131r.<\/p>\n
BA\u011eIRSAK SALGISI: Bilindi\u011fi gibi ba\u011f\u0131rsaklarda ba\u015fl\u0131ca iki \u00e7e\u015fit salg\u0131 bezi bulunmaktad\u0131r. Bunlardan biri Brunner bezleridir. Bu bezlerden, mukus i\u00e7eren alkalinden zengin bir salg\u0131 salg\u0131lanmaktad\u0131r. Liberk\u00fchn kriptalar\u0131 denilen di\u011fer salg\u0131 bezlerinden ise, enterokinaz salg\u0131lanmaktad\u0131r. Enterokinaz protein sindiriminde rol oynamaktad\u0131r. Bu enzimler karbonhidratlar \u00fczerinde etkilidir. Ba\u011f\u0131rsaklardan salg\u0131lanan \u201cn\u00fckleaz\u201d adl\u0131 bir enzim ise n\u00fckleik asitler \u00fczerinde etkilidir.<\/p>\n
S\u0130ND\u0130R\u0130M KANALI HORMONLARI: Sindirim kanal\u0131ndan, kana ba\u015fl\u0131ca d\u00f6rt hormon verilmektedir. Bu hormonlar sindirim kanal\u0131 \u00fczerindeki \u00e7e\u015fitli etkileriyle, sindirim i\u015flevinde belli d\u00fczenlemeler yapmaktad\u0131rlar. Bu hormonlar gastrin, sekretin, kolesistokinin pankreozimin (CCK-PZ) ve enterogastrondur. <\/p>\n
Gastrin midenin antrum b\u00f6lgesindeki mukozas\u0131nda bulunan G-h\u00fccrelerinden kana verilmektedir. Kana kar\u0131\u015fan gastrin midenin fundus b\u00f6lgesindeki parietal h\u00fccrelere ula\u015ft\u0131\u011f\u0131nda, bu h\u00fccrelerden HCI salg\u0131lanmas\u0131na yol a\u00e7ar. Antrum b\u00f6lgesinin besinlerle gerilmesi, buradaki asitli\u011fin azalmas\u0131 ve vagus sinirinin etkisi gastrin salg\u0131s\u0131n\u0131 uyar\u0131r. <\/p>\n
Sekretin adl\u0131 hormon ise duodenumdaki epitel h\u00fccreleri taraf\u0131ndan salg\u0131lanmaktad\u0131r. Bu hormon kan yoluyla pankreasa ula\u015ft\u0131\u011f\u0131nda, bu organdan bikarbonattan zengin bir salg\u0131n\u0131n salg\u0131lanmas\u0131na yol a\u00e7ar. Sekretin mide salg\u0131s\u0131n\u0131 azalt\u0131c\u0131 etkiye de sahip olan bir hormondur.<\/p>\n
Kolesistokinin-pankreozimin (CCK-PZ) hormonu, inceba\u011f\u0131rsaklar\u0131n ba\u015flang\u0131\u00e7 b\u00f6l\u00fcmlerinden kana salg\u0131lanmaktad\u0131rlar. CCK-PZ pankreastan, enzim bak\u0131m\u0131ndan zengin bir salg\u0131n\u0131n salg\u0131lanmas\u0131na, safra kesesinden safra salg\u0131lanmas\u0131na ve oddi sfinkterinin ise geni\u015flemesine yol a\u00e7ar. <\/p>\n
Duodenumdan salg\u0131lanmakta olan enterogastron ise midenin salg\u0131s\u0131n\u0131 ve kas\u0131lma hareketlerini azalt\u0131r.<\/p>\n","protected":false},"excerpt":{"rendered":"
S\u0130ND\u0130R\u0130M S\u0130STEM\u0130NE GENEL BAKI\u015e Sindirim sistemi, yakla\u015f\u0131k 9 m uzunlu\u011funda olan sindirim kanal\u0131, bu kanala sindirim olay\u0131yla ilgili salg\u0131lar\u0131n\u0131 ak\u0131tan \u201cSalg\u0131 bezleri\u201d ve di\u015flerden olu\u015fmu\u015ftur. Sindirim kanal\u0131n\u0131n b\u00f6l\u00fcmlerini a\u011f\u0131zdan ba\u015flayarak s\u0131ralarsak \u015fu b\u00f6l\u00fcmlerle kar\u015f\u0131la\u015f\u0131r\u0131z: 1) A\u011f\u0131z bo\u015flu\u011fu 2) Farinks (yutak) 3) \u00d6zofagus (yemek borusu) 4) Mide 5) \u0130nceba\u011f\u0131rsaklar a) Duodenum (onikiparmak ba\u011f\u0131rsa\u011f\u0131) b) Jejunum c) …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1407,1403],"tags":[2292,2294,2296,2293,2298,2291,973,2295,2297],"class_list":["post-778","post","type-post","status-publish","format-standard","hentry","category-fen-ve-teknoloji-odevleri","category-odevler","tag-farinks","tag-incebagirsak","tag-onikiparmak-bagirsagi","tag-ozofagus","tag-pankreas","tag-salgi-bezleri","tag-sindirim-sistemi","tag-tukuruk-bezleri","tag-uterus"],"_links":{"self":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/778","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/comments?post=778"}],"version-history":[{"count":0,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/778\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/media?parent=778"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/categories?post=778"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/tags?post=778"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}