Alimentary System 解剖學科徐淑媛

Transcription

1 Alimentary System 解剖學科徐淑媛

2 本堂重點 1. Structures derived from primitive guts 2. Specific events

3 Alimentary System endoderm of primordial gut epithelium & glands of digestive tract ectoderm of stomodeum epithelium of mouth ectoderm of proctodeum epithelium of anus splanchnic mesenchyme muscle, connective tissue & other tissues Fig. 11-1

4 Alimentary recanalization & rotation Fig Fig

5 Alimentary System Foregut Midgut Hindgut Fig. 11-1

6 Foregut -- primordial pharynx : oral cavity, tongue, tonsils, salivary glands -- lower respiratory system -- esophagus, stomach, proximal duodenum, liver, gallbladder, pancreas, spleen -- supplied by celiac trunk Fig. 11-1

7 Foregut Esophagus -- superior 1/3 striated muscles are derived from mesenchyme of lower pharyngeal arches -- inferior 1/3 smooth muscles are derived from splanchnic mesenchyme -- innervated by vagus nerve Fig. 11-1

8 Foregut Stomach -- the dorsal border grows faster than the ventral border -- rotate 90 degrees in a clockwise direction -- ventral border (lesser curvature) to the right, dorsal border (greater curvature) to the left -- left vagus innervate anterior wall, right vagus supply posterior wall Fig Fig. 11-2

9 Foregut Stomach -- the dorsal border grows faster than the ventral border -- rotate 90 degrees in a clockwise direction -- ventral border (lesser curvature) to the right, dorsal border (greater curvature) to the left -- left vagus innervate anterior wall, right vagus supply posterior wall From Moore: Clinical Oriented Anatomy Fig. 11-2

10 Foregut Stomach -- mesentery -- ventral mesogastrium lesser omentum + falciform lig. -- dorsal mesogastrium greater omentum + gastrosplenic lig. + splenorenal lig. ventral mesogastrium dorsal mesogastrium dorsal mesogastrium ventral mesogastrium Fig Fig. 11-2

11 Foregut Stomach -- mesentery -- ventral mesogastrium lesser omentum + falciform lig. -- dorsal mesogastrium greater omentum + gastrosplenic lig. + splenorenal lig. dorsal mesogastrium ventral mesogastrium Fig Fig. 11-2

12 Foregut Stomach -- omental bursa, omental foramen Fig Fig. 11-3

13 Foregut Duodenum -- caudal part of foregut + cranial part of midgut -- junction : distal to origin of bile duct -- blood supply : celiac trunk & superior mesenteric artery -- rotate to the right Fig Fig. 11-5

14 Liver & Gallbladder Foregut -- hepatic diverticulum -- primordium of liver -- small caudal part Fig. Fig. 11-5

15 Liver & Gallbladder -- hepatic diverticulum -- primordium of liver -- hepatocytes (hepatic cords) & epithelia of intrahepatic biliary ducts come from endoderm -- connective tissue, hepatic sinusoids & Kuppfer cells are derived from mesenchyme -- small caudal part -- gallbladder, cystic duct & bile duct Foregut Fig

16 Liver & Gallbladder -- ventral mesentery -- lesser omentum & falciform ligament -- umbilical vein : pass through inferior border of faciform ligament Foregut Fig

17 Foregut Pancreas -- dorsal & ventral pancreatic buds -- fused & lies retroperitoneally because of the rotation of duodenum -- parenchyma is derived from the endoderm -- pancreatic islets develop from group of cells separated from tubules -- connective tissue sheath develop from the surrounding splanchnic mesenchyme ge041.jpg Fig

18 Foregut Pancreas -- dorsal & ventral pancreatic buds -- fused & lies retroperitoneally because of the rotation of duodenum Pancreas_rotation.jpg Fig

19 Foregut Spleen -- derived from mesenchymal cells in dorsal mesogastrium Fig Fig. 11-2

20 Midgut -- small intestine, cecum, appendix, ascending colon, right 2/3 of transverse colon -- supplied by superior mesenteric artery -- midgut loop Fig. 11-9

21 Midgut midgut loop -- physiological umbilical herniation -- no space of abdomen (large liver & two sets of kidneys) -- cranial limb : small intestinal loops -- caudal limb : parts of small & large intestine; cecum & appendix (cecal swelling) Fig

22 Midgut midgut loop -- rotation : 90 degrees counterclockwise -- cranial limb to the right, caudal limb to the left -- return -- small intestine first : central part -- large intestine return & rotate further 180 degrees counterclockwise Fig From Moore: Clinical Oriented Anatomy

23 Midgut midgut loop -- rotation : 90 degrees counterclockwise -- cranial limb to the right, caudal limb to the left -- return -- small intestine first : central part -- large intestine return & rotate further 180 degrees counterclockwise Fig

24 From Moore: Clinical Oriented Anatomy Midgut

25 Midgut -- fixation : fusion of mesentery & peritoneum Fig Fig

26 Hindgut -- left 1/3 of transverse colon, descending & sigmoid colon, rectum, superior anal canal -- epithelium of urinary bladder & most of urethra -- supplied by inferior mesenteric artery Fig. 11-1

27 Hindgut -- left 1/3 of transverse colon, descending & sigmoid colon, rectum, superior anal canal -- epithelium of urinary bladder & most of urethra -- supplied by inferior mesenteric artery Fig

28 Hindgut -- cloaca -- cloacal membrane = endoderm of cloaca + ectoderm of proctodeum (anal pit) -- urorectal septum (mesenchyme) -- dorsal : rectum & superior part of anal canal -- ventral : urogenital sinus Fig

29 Anal Canal upper 2/3 (25 mm) lower 1/3 (13 mm) Hindgut origin vessel innervation epithelium carcinoma hindgut proctodeum superior rectal (inferior mesenteric) inferior rectal (internal pudendal) ANS columnar painless inferior rectal n. (keratinized) stratified squamous painful From Gray s Anatomy for Students Fig

30 Alimentary system 1. Structures derived from primitive guts 2. Specific events