Large Intestine by Dr. Rabia Inam Gandapore.pptx

Gross Anatomy

1. LARGE INTESTINE 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)

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 Large Intestine (cecum, ascending, transverse and descending, sigmoid colon, and anal canal).

4. Specific Learning Objectives (cognitive) At the end of the lecture the student will able to: Describe the gross features of Large Intestine (cecum, ascending, transverse and descending, sigmoid colon, and anal canal).

5. Psychomotor Objective: (Guided response) A student to draw diagrammatic representation of Large 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 Large intestine Outline: Activity 1 Describe features of Large 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. Large Instestine E xtends from ileum to anus & divided into: Caecum A scending colon T ransverse colon D escending colon S igmoid colon Rectum & anal canal are considered in sections on pelvis & perineum. P rimary function: storage of water, electrolytes , undigested material & expelled from body as faeces .

10. 1.CAECUM Location and description L ies below: junction of ileum, a blind ended pouch that is located in right iliac fossa . About: 2.5in (6 cm) long Covered: completely peritoneum. Posses: considerable amount of mobility, does not have a mesentery. P osteromedial surface: is appendix . Folds: in vicinity of caecum creates: S uperior ileocecal I nferior ileocecal R etro ileocecal muscles .

11. As in colon, longitudinal muscle is restricted to 3 flat bands = Taeniae coli which converges on base of appendix & provide for it a complete longitudinal muscle coat . C aecum is distended with gas & can be palpated through anterior abdominal wall in a living patient. Terminal part of ileum enters large intestine at junction of caecum with ascending colon . O pening is provided with 2 folds or lips which forms ileocecal valve . A ppendix communicates with caecum through opening below & behind ileocecal opening .

12. Relations Anteriorly : C oils of small intestine P art of greater omentum A nterior abdominal wall in right iliac region. Posteriorly: Psoas I liac muscles F emoral nerve L ateral cutaneous nerve of thigh Appendix (Behind & Medially)

13. Vasculature BLOOD SUPPLY Arteries: Anterior & posterior cecal artery from ileocolic artery (branch of superior mesenteric artery ) Veins: veins correspond to arteries & drain into superior mesenteric vein . LYMPATHIC DRAINGE: pass via mesenteric nodes & reach superior mesenteric node . NERVE SUPPLY: Sympathetic & parasympathetic nerves( vagus ) from superior mesenteric plexus .

14. Ileocecal Valve R udimentary structure consist of 2 folds of mucous membrane that project around orifice of ileum. V alve play little or no part in prevention of reflux of cecal contents into ileum. C ircular muscle at end of ileum(called ileocecal sphincter )serves as sphincter & control flow of content from ileum to colon. S mooth muscle tone reflex increased when caecum is distended ; hormone gastrin , which is released by stomach causes relaxation of muscle tone .

15. 2. Appendix LOCATON & DESCRIPTION N arrow muscular containing large amount of lymphoid tissue . Length: 3 to 5 in (8 - 13 cm) Base: attached to posteromedial surface of caecum about 1 in(2.5 cm) below ileocecal junction & rest of appendix is free. C omplete peritoneal covering which is attached to mesentery of small intestine by a mesentery of its own , mesoappendix it contains appendicular vessels & nerves . Lies: in right iliac fossa & in relation to anterior abdominal wall Base: situated 1/3 rd of way above line joining right anterior superior iliac spine to umbilicus ( McBurney’s point ). Inside abdomen: base of appendix found by identifying tineae coli of caecum & tracing them to base of appendix , where they converge to form tenuous longitudinal muscle coat.

16. Common Positions Of Tip Of Appendix F ound in following positions: H anging down into pelvis against right pelvic wall . C oiled up behind caecum . P rojecting upward along lateral wall of caecum . In front or behind terminal part of ileum . First & second position are most common sites.

17. Vasculature BLOOD SUPPLY Arteries: A ppendicular artery (branch of posterior cecal artery) Veins : A ppendicular veins drain into posterior cecal vein. LYMPH DRAINAGE D rain into one or two nodes lying in mesoappendix & eventually into superior mesenteric nodes. NERVE SUPPLY S ympathetic & parasympathetic ( vagus ) nerves of superior mesenteric plexus . Afferent fibers concerned with conduction of visceral pain from appendix, accompany sympathetic nerves & enter spinal cord at level of T10 segment .

18. 3. Ascending Colon LOCATION AND DESCRIPTION Size: 5 in ( 13cm) & lies in right lower quadrant . Extends: upward from caecum towards inferior surface of right lobe of liver , where it turns to left forming right colic flexure & becomes continuous with transverse colon . P eritoneum covers right & front of ascending colon, binding it to posterior abdominal wall .

19. Relations Anteriorly : C oils of small intestine G reater omentum A nterior abdominal wall Posteriorly: Iliacal I lliacal crest Q uadrant lumborum O rigin of transverse abdominis muscle L ower pole of right kidney. Iliohypogastric & iliolingual nerves pass behind it

20. Vasculature BLOOD SUPPLY Arteries : ileocolic & right colic (branches of mesenteric artery) Veins: veins correspond to arteries & drain in superior mesenteric vein. LYMPH DRAINAGE D rain into nodes along course of colic blood vessels & ultimately drain into superior mesenteric nodes . NERVE SUPPLY S ympathetic & parasympathetic ( vagus ) nerves from superior mesenteric plexus supply this area of colon.

21. 4. Transverse Colon LOCATION AND DESCRIPTION A bout 15 in(38 cm) long Extends: across abdomen , occupying umbilical region . B egins at right colic flexure below right lobe of liver & hangs downward suspended by transverse mesocolon from pancreas . It then ascends to form left colic flexure below spleen . L eft colic flexure is higher than right colic flexure & suspended from diaphragm by phrenocolic ligament . Transverse mesocolon suspends transverse colon from anterior border of pancreas . Lengths of transverse mesocolon reach as far as pelvis .

22. Relations Anteriorly : G reater omentum A nterior abdominal wall (umbilical & hypogastric region ). Posteriorly : Second part of duodenum P art of pancreas C oils of jejunum & ileum.

23. Vasculature BLOOD SUPPLY Arteries : Proximal 2/3 rd supplied by middle colic artery (branch of superior mesenteric artery). D istal end: supplied by left colic artery (branch of inferior mesenteric artery). Veins: correspond to arteries & drain into superior & inferior mesenteric arteries . LYMPH DRAINAGE P roximal 2/3 rd drain into colic nodes & then into superior mesenteric nodes . D istal 3rd drain into colic nodes & then into inferior mesenteric nodes . NERVE SUPPLY P roximal 2/3 rd : innervated by sympathetic & vagul nerves from superior mesenteric plexus . D istal 3 rd : innervated by sympathetic & parasympathetic pelvic sphlanic nerves via inferior mesenteric plexus.

24. 5. Descending Colon LOCATION AND DESCRIPTION About: 20in (25cm) long & lies in left upper & lower quandrant Extends: downwards from left colic flexure to pelvic brim & continuous with sigmoid colon . Peritonium : covers front, side & binds it to posterior abdominal wall . RELATIONS Posteriorly: lateral border of left kidney O rigin of transverse abdominus muscle Q uadratus lumborum I liac crest Illiacus L eft psoas. Iliohypogastric & I liolingual nerves, lateral cutaneous nerve of thigh & femoral nerve also lies posteriorly. Anteriorly: C oils of small intestine G reat omentum A nterior abdominal wall.

25. Vasculature BLOOD SUPPLY Arteries: left colic & sigmoid branch of left mesenteric artery Veins: correspond arteries & drain into inferior mesenteric vein. LYMPH DRAINAGE D rain into colic nodes which then drain into inferior mesenteric nodes NERVE SUPPLY S ympathetic & parasympathetic pelvic sphlanic nerve through inferior mesenteric plexus .

26. 6. SIGMOID COLON LOCATION AND DESCRIPTION Shape & Size: Curved , S-shaped tube 15-20 in (38-51 cm) long. Located: lower left abdomen above pelvis. Begins: at junction of descending colon & rectum , near iliac crest. Ends: at rectosigmoid junction & joins rectum. M obile part of colon . H as mesentery that attaches it to posterior abdominal wall . RELATIONS Anteriorly: urinary bladder;uterus & upper vagina(in femlaes only). Posteriorly: rectum ; sacrum & ileum are present .

27. Vasculature BLOOD SUPPLY Arteries: sigmoid arteries (branches of inferior mesenteric artery). Veins: correspond arteries & drain into inferior mesenteric vein . LYMPH DRAINAGE D rains into left colic nodes which drains into inferior mesenteric nodes. NERVE SUPPLY Sympathetic & parasympathetic pelvic sphlanic nerves through inferior mesenteric plexus .

28. 7. RECTUM LOCATION AND DESCRIPTION Shape & Size: Muscular tube, 10-15 cm (4-6 inches) long. Diameter: 4-6 cm (1.6-2.4 inches) Expanding: to about 7-8 cm (2.8-3.2 inches) during defecation . Location: pelvic cavity , just below sigmoid colon. Begins: at rectosigmoid junction Ends: at anus S urrounded by: pelvis & is supported by pelvic floor muscles . RELATIONS Anterior : Male: retrovesical pouch ; sigmoid colon;ileum;bladder;prostate & seminal vesicles. Female: rectouterine pouch ; sigmoid colon;ileum;vagina;cervix . Posterior : S acrum & coccyx ; piriformis;coccygeus;levator ani;sacral plexus .

29. BLOOD SUPPLY Arteries : S uperior rectal artery termination continuation of inferior mesenteric artery; Middle rectal artery ; branch of internal iliac artery; Inferior rectal artery ; branch of internal pudendal artery Veins : Superior rectal vein : drains into portal venous system. Middle & inferior rectal vein : empties into systemic venous system . LYMPH DRAINAGE Pararectal lymph nodes eventually drain into inferior mesenteric nodes L ower aspect finally lead to internal iliac lymph nodes NERVE SUPPLY Sympathetic supply : lumber sphlanic nerve & superior ad inferior hypogastric plexus . Parasympathetic supply: pelvic sphlanic nerve & inferior hypogastric plexus .

30. 8. ANAL CANAL LOCATION AND DESCRIPTION Shape & Size: Narrow , muscular tube,3-4 cm (1.2-1.6 in) long. Diameter: 2-3 cm (0.8-1.2 in), narrowing to 1 cm (0.4 in) at anus. Located: below rectum Extends: from anorectal junction (2-3 cm above anus ) to anus . S urrounded by : pelvic floor muscles & between internal & external anal sphincters that control stool elimination .

31. RELATIONS Anteriorly : Male: perineal gland;urinogenital diaphragm;urethra;bulb of penis . Female: perineal gland;urinogenital diaphragm;vagina . P o steriorly: Anoccygeal ligament;sacrum & coccyx.

32. Vasculature BLOOD SUPPLY ABOVE PECTINATE LINE: Arteries: superior rectal artery (branch of inferior mesenteric artery & middle rectal artery) Veins: superior rectal vein which drains into inferior mesenteric vein. BELOW PECTINATE LINE Arteries: inferioir rectal artery (branch of internal pudendal artery& branches from middle rectal artery). Veins: inferioir rectal vein which empties into internal pudendal vein . LYMPH DRAINAGE ABOVE P ECTINATE LINE: Internal iliac lymph nodes BELOW PECTINATE LINE : Superficial inguinal lymph nodes NERVE SUPPLY ABOVE PECTINATE LINE : Inferior hypogastric plexus BELOW PECTINATE LINE : Inferior rectal nerves (branches of pudendal nerves)

33. Thank You Any questions? Typing credits: Javeria kashaf zain