5-ANATOMY OF SMALL INTESTINE.ppt
- 2. OBJECTIVES At the end of the lecture, students should: List the different parts of small intestine. Describe the anatomy of duodenum, jejunum & ileum regarding: the shape, length, site of beginning & termination, peritoneal covering, arterial supply & lymphatic drainage. Differentiate between each part of duodenum regarding the length, level & relations. Differentiate between the jejunum & ileum regarding the characteristic anatomical features of each of them.
- 3. Posterior abdominal wall Anterior abdominal wall What is MESENTERY? Loop of intestine
- 4. 1 2 FIXED (Retro peritoneal) PART (NO MESENTERY) DUODENUM FREE (MOVABLE) PART (WITH MESENTERY) JEJUNUM & ILEUM
- 5. DUODENUM SHAPE: C-shaped loop LENGTH: 10 inches BEGINNING: at pyloro-duodenal junction TERMINATION: at duodeno-jejunal flexure PERITONEAL COVERING: retroperitoneal
- 6. PARTS • The duodenum is divided into (4) parts: • 1st : Superior. • 2nd : Descending (vertical). • 3rd : Inferior (Horizontal) • 4th : Ascending
- 7. LENGTH – SURFACE ANATOMY PART LENGTH LEVEL FIRST PART (Superior) 2 INCHES L1 (Transpyloric Plane) SECOND PART (Descending 3 INCHES DESCENDS FROM L1 TO L3 THIRD PART (Horizontal) 4 INCHES L3 (SUBCOTAL PLANE) FOURTH PART (Ascending) 1 INCHES ASCENDS FROM L3 TO L2
- 9. RELATIONS OF FIRST PART X Anterior Liver 1) 2) 3) X Posterior 1)Bile duct 2) Gastroduodenal artery 3)Portal vein
- 10. RELATIONS OF SECOND PART X Anterior )Liver )Transverse Colon )Small intestine Posterior Right kidney Lateral R Colic Flexure Medial Pancreas
- 11. OPENINGS IN SECOND PART OF DUODENUM 1. Common opening of bile duct & main pancreatic duct: on summit of major duodenal papilla. 2. Opening of accessory pancreatic duct (one inch higher): on summit of minor duodenal papilla.
- 12. RELATIONS OF THIRD PART Anterior: a)Small intestine b) Superior mesenteric vessels Posterior: 1) Right psoas major 2) Inferior vena cava 3) Abdominal aorta 4) Inferior mesenteric vessels. 1 2 3
- 13. RELATIONS OF FOURTH PART Anterior: Small intestine Posterior: Left psoas major psoas
- 15. Blood Supply & Lymph drainage Because the duodenum is derived from both: Foregut & Midgut, It has its Arterial Supply from : Celiac & Superior mesenteric arteries. Venous Drainage to : Superior mesenteric& Portal veins. LYMPHATIC DRAINAGE: Celiac & Superior mesenteric lymph nodes.
- 16. JEJUNUM & ILEUM SHAPE: Coiled tube LENGTH: 6 meters (20 feet) BEGINNING: at Duodeno- jejunal flexure TERMINATION: at Ilieo- caecal junction EMBRYOLOGICAL ORIGIN: Midgut Blood SUPPLY: Superior mesenteric A & V LYMPHATIC DRAINAGE: Superior mesenteric lymph nodes
- 17. JEJUNUM ILEUM LENGTH Shorter (proximal 2/5) of SI Longer (distal 3/5) of SI DIAMETER Wider Narrower WALL Thicker (more plicae circulares) Thinner (less plicae circulares) APPEARANCE Dark red (more vascular) Light red (less vascular) VESSELS High & Less arcades (long terminal branches) Low & More arcades (short terminal branches MESENTERIC FAT Small amount & away from intestinal border Large amount & close to intestinal border LYMPHOID TISSUE Few aggregations Numerous aggregations (Peyer’s patches)
- 18. THANK YOU