Small Intestine by Dr. Rabia Inam Gandapore.pptx

Gross Anatomy

1. Dr. Rabia Inam Gandapore Assistant Professor Head of Department Anatomy (Dentistry-BKCD) B.D.S (SBDC), M.Phil. Anatomy (KMU), Dip. Implant (Sharjah, Bangkok, ACHERS) , CHPE (KMU),CHR (KMU), Dip. Arts (Florence, Italy) SMALL INTESTINE

2. Teaching Methodology LGF (Long Group Format) SGF (Short Group Format) LGD (Long Group Discussion, Interactive discussion with the use of models or diagrams) SGD (Short Group) SDL (Self-Directed Learning) DSL (Directed-Self Learning) PBL (Problem- Based Learning) Online Teaching Method Role Play Demonstrations Laboratory Museum Library (Computed Assisted Learning or E-Learning) Assignments Video tutorial method

3. Goal/Aim (main objective) Describe the gross features of Small Intestine (jejunum, ileum & appendix)

4. Specific Learning Objectives (cognitive) At the end of the lecture the student will able to: Describe the gross features of Small Intestine (jejunum, ileum, and appendix)

5. Psychomotor Objective: (Guided response) A student to draw diagrammatic representation of Small intestine and its parts

6. Affective domain To be able to display a good code of conduct and moral values in the class. To cooperate with the teacher and in groups with the colleagues. To demonstrate a responsible behavior in the class and be punctual, regular, attentive and on time in the class. To be able to perform well in the class under the guidance and supervision of the teacher. Study the topic before entering the class. Discuss among colleagues the topic under discussion in SGDs. Participate in group activities and museum classes and follow the rules. Volunteer to participate in psychomotor activities. Listen to the teacher's instructions carefully and follow the guidelines. Ask questions in the class by raising hand and avoid creating a disturbance. To be able to submit all assignments on time and get your sketch logbooks checked .

7. Lesson contents Clinical chair side question: Students will be asked if they know what is the function of Small intestine Outline: Activity 1 Describe features of Small Intestine and its parts

8. Recommendations Students assessment: MCQs, Flashcards, Diagrams labeling. Learning resources: Langman’s T.W. Sadler, Laiq Hussain Siddiqui, Snell Clinical Anatomy , Netter’s Atlas , BD Chaurasia’s Human anatomy, Internet sources links.

9. SMALL INTESTINE L ongest part of alimentary canal E xtends from pylorus of stomatch to illeoceccal junction . G reater part of digestion & food absorption takes place D ivided into 3 parts ; Duodenum Jejunum Ileum

10. DUODENUM

11. A. DUODENUM C -shaped tube 10in.( 25cm) long J oins stomach to jejunum . R ecieves : openings of bile & pancreatic ducts It curves around head of pancreas . F irst inch of duodenum: resembles stomach i.e. covered on its anterior & posterior surfaces with peritoneum has L esser omentum attached to its upper border G reater omentum attached to its lower border ; lesser sac lies behind this short segment . R emainder of duodenum is retroperitoneal partially covered by peritoneum

12. PARTS OF DUODENUM Its situated in epigastric & umbilical regions , divided into 4 parts . 1. FIRST PART OF DUODENUM Begins at pylorus & runs upward & backward on transpyloric plane at level of L1 vertebra . Relations as follows: Anteriorly : Q uadrate lobe of liver & gallbladder .

13. Contd. POSTERIORLY : L esser sac (first inch only ) G astroduodenal artery B ile duct P ortal vein I nferior vena cava

14. Contd. SUPERIORLY : E ntrance into lesser sac ( epiploic foramen)

15. CONTD. INFERIORLY : H ead of pancreas

16. 2. SECOND PART OF DUODENUM Runs vertically downward in front of hilum of right kidney on right side of L2 & L3 vertebrae About halfway down its medial border , bile duct & main pancreatic duct pierce duodenal wall & unite to form ampulla that opens on summit of major duodenal papilla . A ccessory pancreatic duct , if present, opens into duodenum a little higher up on minor duodenal papilla

17. Relations Anteriorly: fundus of gallbladder & right lobe of liver, transverse colon, & coils of small intestine . Posteriorly : hilum of right kidney & right ureter . Laterally : A scending colon , right colic flexure, right lobe of liver . Medially : H ead of pancreas , bile duct , & main pancreatic duct .

18. 3. THIRD PART OF DUODENUM R uns horizontally to left on subcostal plane , passing in front of vertebral column & following lower margin of head of pancreas . Relations: Anteriorly: root of mesentery of small intestine, superior mesenteric vessels & coils of jejunum . Posteriorly: right ureter , right psoas muscle, inferior vena cava & aorta . Superiorly: head of pancreas . Inferiorly: Coils of jejunum

19. 4. FOURTH PART OF DUODENUM R uns upward & to left to duodenojejunal flexure . F lexure is held in position by a peritoneal fold, suspensory ligament of duodenum (ligament of Treitz ), which is attached to right crus of diaphragm . Relations : Anteriorly: B eginning of root of mesentery & coils of jejunum . Posteriorly : L eft margin of aorta & medial border of left psoas muscle

20. MUCOUS MEMBRANE & DUODENAL PAPILLAE M ucous membrane of duodenum : thick . Its smooth in first part of duodenum . C ircular folds called plicae circulares in remainder of duodenum . A small, rounded elevation called major duodenal papilla is located at site where bile duct & main pancreatic duct pierce medial wall of second part. A ccessory pancreatic duct , if present, opens into duodenum on a smaller papilla about 0.75 in. (1.9 cm) above major duodenal papilla.

21. Blood supply Arteries: Upper half: Superior pancreaticoduodenal artery (branch of gastroduodenal artery) L ower half: Inferior pancreaticoduodenal artery (branch of superior mesenteric artery ) Veins: Superior pancreaticoduodenal vein drains into portal vein . I nferior vein joins superior mesenteric vein .

22. Lymph drainage & nerve supply Lymph Drainage Upper duodenum: drains via pancreaticoduodenal nodes to gastroduodenal nodes & then to celiac nodes . L ower duodenum: drains via pancreaticoduodenal nodes to superior mesenteric nodes around origin of superior mesenteric artery . Nerve Supply Sympathetic & parasympathetic ( vagus ) nerves derived from celiac & superior mesenteric plexuses supply duodenum

23. JEJUNUM AND ILEUM

24. B & C. JEJUNUM AND ILEUM Together: 20 ft (6 m) long . Jejunum makes up upper 2/5th of this. Jejunum begins at duodenojejunal flexure I leum ends at ileocecal junction . Location & Description C oils of jejunum & ileum are freely mobile & are attached to posterior abdominal wall by a fan-shaped fold of peritoneum known as mesentery of small intestine . Long free edge of fold encloses mobile intestine. S hort root of fold is continuous with parietal peritoneum on posterior abdominal wall along a line that extends downward & to right from left side of L2 vertebra to region of right sacroiliac joint . R oot of mesentery permits entrance & exit of branches of superior mesenteric artery & vein, lymph vessels, & nerves into space between 2 layers of peritoneum forming mesentery .

25. DISTINGUISHING FEATURES OF JEJUNUM & ILEUM # Jejunum Ileum 1 Li es coiled in upper part of peritoneal cavity below left side of transverse mesocolon Is i n lower part of cavity & in pelvis 2 It s wider bored, thicker walled ( because of infoldings plicae circulare s are larger, more numerous, & closely set in jejunum ) & redder than ileum. Upper part of ileum, plicae circulare s are smaller & more widely separated Lower part, they are absent . 3 Jejunal mesentery is attached to posterior abdominal wall above & to left of aorta ileal mesentery is attached below & to right of aorta .

26. # Jejunum Ileum 4 Jejunal mesenteric vessels form only one or two arcades, with long & infrequent branches ( vasa recta ) passing to intestinal wall. Ileum receives numerous short terminal vasa recta that arise from a series of three or four or even more arcades. 5 At jejunal end of mesentery, fat is deposited near root & is scanty near intestinal wall. At ileal end of mesentery, fat is deposited throughout so that it extends from root to intestinal wall. 6 Aggregations of lymphoid tissue ( Peyer patches ) are present in mucous membrane of lower ileum along anti-mesenteric border. In living, these may be visible through wall of ileum from outside .

27. BLOOD SUPPLY A rterial supply: branches of superior mesenteric artery . I ntestinal branches arise from left side of artery & run in mesentery to reach gut . They anastomose with one another to form a series of archlike arcades . Multiple straight vessels ( vasa recta ; arteriae rectae ) branch off arcades & run to wall of intestine. I leocolic artery supplies lowest part of ileum . Veins: correspond to branches of superior mesenteric artery & drain into superior mesenteric vein

28. LYMPH DRAINAGE & NERVE SUPPLY Lymph Drainage: superior mesenteric nodes (Situated around origin of superior mesenteric artery). Nerve Supply: Sympathetic & parasympathetic ( vagus ) nerves derived from superior mesenteric plexus supply jejunum & ileum

29. Appendix Origin: from postero -medial aspect of   cecum . Its supported by meso -appendix , a fold of mesentery which suspends appendix from terminal ileum . P osition of free-end of appendix is highly variable & can be categorised into 7 main locations depending on its relationship to ileum , caecum or pelvis . M ost common position is   retrocecal . 

30. They may also be remembered by their relationship to a clock face: Pre- ileal : anterior to terminal ileum – 1 or 2 o’clock. Post- ileal : posterior to terminal ileum – 1 or 2 o’clock. Sub- ileal : parallel with terminal ileum – 3 o’clock. Pelvic : descending over pelvic brim – 5 o’clock. Subcecal : below cecum – 6 o’clock. Paracecal : alongside lateral border of cecum – 10 o’clock. Retrocecal : behind cecum – 11 o’clock.

31. Neurovascular Supply B ranches of superior mesenteric vessels . Arterial supply: is from   appendicular artery  (derived from ileocolic artery, a branch of superior mesenteric artery) Veins: is via corresponding  appendicular vein. Both are contained within mesoappendix . Nerve Supply : Sympathetic & parasympathetic branches of autonomic nervous system by ileocolic branch of superior mesenteric plexus . It  accompanies ileocolic artery to reach appendix . S ympathetic afferent fibres of appendix arise from T10 of spinal cord – visceral pain of early appendicitis is felt centrally within abdomen.

32. Lymphatic Drainage D rains into lymph nodes within mesoappendix & into ileocolic lymph nodes  (which surround ileocolic artery ).

33. Thank You ANY QUESTIONS ? Typing Credits: MaRiam Amjad