In the name of Allah

Jejunum and ileum Rest of the small intestine From duodenojejunal flexure To ileocecal junction Intraperitoneal Attached to the posterior abdominal wall by mesentery of small intestine Relations Anterior abdominal wall Greater omentum Posterior abdominal wall Retroperitoneal structures

Ileum Jejunum In umbilical region of peritoneal cavity First 2:5 of small intestine Diameter 4cm Mucosal folds are large and frequent Thicker wall More vascular Redder in life Arterial arcade less Aggregated lymphatic follicles are lesser Intermesenteric fat less In lower part of peritoneal cavity Second 3:5 of small intestine Diameter 3.5 cm Mucosal folds are small and few Thinner wall Less vascular Paler in life Arterial arcade more Aggregated lymphatic follicles are more Intermesenteric fat more

Ileum Ileal or Meckel’s diverticulum

Large intestine

Large intestine 1.5 m From caecum to anus Includes; Cecum and appendix Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Anal canal

Large intestine Differs from small intestine in the: More fixed in position Greater caliber Taeniae coli Sacculation (haustration) Appendices epiploic

Cecum In the right iliac fossa 6.5*7.5 cm Related posteriorly to the iliacus & psoas mm lateral cutaneous N of thigh femoral nerve Related anteriorly to the: ant. Abdominal wall Small intestine Greater omentum

Caecum Intraperitoneal sup. & inf. Ileucecal and retrocecal recesses

ileocecal valve Sup & inf. Lip and frenulum Posteromedial of cecum At the level of transetubercular and midclavicular lines

Vermiform appendix In the right iliac fossa McBurney’s point 2 cm below the ileocecal junction Length 2-20cm average 9cm Intraperitoneal Position Retrocecal & retrocolic 64% Pelvic 30% Subcecal 2.5% pre and postileal 1.5%

Ascending colon 15 cm from cecum to hepatic flexure Covered in front and sides by peritoneum Taeniae coli ant., med. & lat. Relation Posteriorly Quadratus and iliacus Lateral cutaneous N of thigh Iliohypogastric Ilio-inguinal

Ascending colon Relations anteriorly Small intestine Ant. Abdominal wall Greater omentum

Right or hepatic flexure Turns down and forward Kidney posterior Liver anterosuperior and lateral Duodenum medial Gall bladder anteromedial

Transverse colon 50 cm, from hepatic to splenic flexures From Rt. Lumbar To Lt. hypochondrium Intraperitoneal and attached to the post. abdominal wall by meso. Taeniae

Transverse colon Relations anterior Omentum Ant. abdominal wall posterior Pancreas 2nd part of duodenum

Lt. colic flexure Higher than right relations Spleen Pancreas Lt. kidney Phrenicocolic

Descending colon 25 cm from splenic flexure to pelvic brim Two parts Covered anterioly by peritineum

Descending colon Relations: Anterior same as the right Posterior: Kidney Subcostal nerve Iliohypogastric Ilioinguinal Lateral cutaneous N of thigh

Sigmoid colon 25- 40 cm from pelvic brim to S3 Has meso. Lateral limb Medial limb in front of sacrum Intersigmoid recess

Sigmoid colon Relations Posterior Rectum Sacrum Ureter Anterior Uterus bladder

Rectum 10-15 cm From S3 To tip of coccyx continuous as the anal canal Piercing pelvic diaphragm Passing downward following the curve of sacrum Deviate to the left and turns right Rectal ampulla Anorectal angle

Rectum Peritonial covering Muscular coat Transverse fold

Rectum Relations: Posteriorly; Sacrum Coccyx Piriformis Coccygeus Lavator ani Sacral plexus Sympathetic chain

Rectum Relations Anteriorly In male Sigmoid colon Ileum Bladder Vas deferens Seminal vesicle prostate

Rectum Relations Anteriorly In female Sigmoid colon Ileum Rectouterine (Douglas) pouch Uterus Vagina

Small and large intestine Artery Superior mesenteric (small & large) Inferior mesenteric (large) Internal iliac (rectum & anal canal) Vein Internal iliac (same as artery)

Anal canal 4-5 cm From the rectal ampulla To the anus Relations Posteriorly Anococcygeal body Anteriorly Male Perineal body Urogenital diaphragm Urethra Bulb of penis

Anal canal Female Perineal body Urogenital diaphragm Vagina Laterally - Ischiorectal fossae

Anal canal Upper half Derived from endoderm Anal culumns Anal valves Anal sinuses Autonomic nerve Sensitive to stretch Artery and vein from and to inferior mesenteric

Anal canal Lower half Derived from ectoderm Has no anal columns Somatic nerve, inferior rectal Sensitive to pain, temperature, touch, pressure Art. And vein from and to internal iliac Pectinate line

Anal canal Muscle coat Internal sphincter (smooth muscle) External sphincter Subcutaneous Superficial Deep Puborectalis Anorectal ring Puborectalis + internal sphincter + deep part of ext. sphincter

innervation Autonomic Somatic Inferior rectal

Rectum and anal canal Blood supply Arteries: Superior rectal Middle rectal Inferior rectal Veins: