Lower gastrointestinal tractHepatobiliary system

Blood and nerve supplies of abdominal organs

BMES310 Human Gastrointestinal System and Nutrition

Kittikun Viwatpinyo, Ph.D.

Lower GI tract

From duodenojejunaljunction to anal canal

Jejunum and ileum of small intestine

Large intestine Rectum and anal

canal

Jejunum and Ileum

Major parts of small intestine (6-7 m.) IntraperitonealMesentery

Jejunum and Ileum

Different features between jejunum and ileum Arterial arcades and vasa recta Fat in mesentery Plicae circulares

Large intestine

Three prominent features of large intestine

Teniae coli Omental

appendices

Haustra

Large intestine

Cecum and vermiform appendix Ileocecal orifice and valve Appendix with mesoappendix

Large intestine

Parts of colon Ascending colon Transverse colon Descending colon Sigmoid colon

Rectum and anal canal

Position of rectum and anal canal in pelvic cavity

Rectum and anal canal

Transverse rectal folds Vascular plexus hemorrhoids

Rectum and anal canal

Parts and internal features of anal canal

Rectum and anal canal

Pectinate line : boundary between somatic and visceral neurovascular supplies

Autonomic nerves

Somatic nerves

Internal iliac lymph nodes

Superficial inguinal lymph nodes

Inf mesenteric a. Hepatic portal v.

Internal iliac a. Inferior vena cava

Pectinate line

Hindgut endoderm

Proctodeumectoderm

Rectum and anal canal

Anorectal flexure : tonic contraction of puborectalis muscle

Control of fecal incontinence

Rectum and anal canal

Sphincters of anal canal Internal anal sphincter : autonomic control External anal sphincter : somatic control

Hepatobiliary system

Passage of biliary tract Liver Gallbladder and bile duct Pancreas

Liver

Surface relationship with ribs Right ribs 5-10 Shifts inferiorly during full inspiration

Liver

Covered by peritoneum except for bare area Subphrenic recess Hepatorenal recess

Liver

Ligaments holding liver in place

Falciform ligament Triangular ligament Coronary ligament

Liver

Lesser omentum holds visceral surface of liver with stomach and duodenum

Hepatogastric ligament Hepatoduodenal ligament

Liver

Lobes and segments

Liver

Lobes and segments

Liver

Structures in the porta hepatis Hepatic portal vein Hepatic artery proper Bile duct

Liver

Functional lobes of liver

Gallbladder

Parts : Fundus, body and neck Outflow tract : cystic duct

Biliary tract

Pancreas

Retroperitoneal organ in the stomach bed

Head, uncinated process, neck, body and tail

Pancreas

Main pancreatic duct Joins common bile duct at hepatopancreatic ampulla

Arterial supply

Arterial system of abdomen is derived from abdominal aorta

Arterial supply

Unpaired branches of abdominal aorta supply each parts of GI tract

Celiac trunk : foregut Superior mesenteric artery :

midgut

Inferior mesenteric artery : hindgut

Celiac trunk

Three major arteries from celiac trunk Left gastric artery Splenic artery Common hepatic

artery

Celiac trunk

Left gastric a. Esophageal

branch

Splenic a. Pancreatic

branches

Left gastro-omental artery

Short gastric artery

Celiac trunk

Common hepatic a. Gastro-duodenal a. Right gastric a. Hepatic artery

proper

Superior mesenteric artery

SMA supplies midgut from duodenum to proximal 2/3 of transverse colon

Inf pancreatico-duodenal a. Jejunal and ileal aa. Middle colic a. Right colic a. Ileocolic a.

Inferior mesenteric artery

IMA supplies hindgut from distal 1/3 of transverse colon to anal canal

Left colic a. Sigmoid a. Superior rectal a.

Arterial supply

Anastomoses between celiac trunk, SMA and IMA

Pancreatico-duodenal Marginal artery of

Drummond

Rectal plexus

Venous drainage

Hepatic portal vein Splenic v. Superior

mesenteric v.

Venous drainage

Portocaval anastomosis : Portal hypertension

Lymphatic drainage

Preaortic lymph nodes

Celiac lymph nodes

Gastric/Gastro-omental/Pyloric nodes

Pancreaticosplenic/Pancreticoduodenal nodes

Hepatic/Cystic nodes

Superior mesenteric lymph nodes

Inferior mesenteric lymph nodes

Mesenteric/Colic nodes

Intestinal lymph trunk

Cisterna chyli

Nerve supply of abdominal organs

Autonomic nervous system of abdomen Sympathetic : Splanchnic nerves from thoracic to

sacral levels

Parasympathetic : Vagus nerve and Pelvic splanchnic nerves

Autonomic periarterial plexuses

Nerve supply of abdominal organs

Sympathetic division

Splanchnic nerves Greater, lesser, least Lumbar Sacral

Postganglionic neurons in prevertebral ganglia

Celiac Superior mesenteric Inferior mesenteric

Parasympathetic division

Vagus nerve : foregut and midgut

Pelvic splanchnic nerves : hindgut

Autonomic plexuses

Visceral referred pain

Brain interprets visceral pain as it comes from related dermatomes

Visceral referred pain

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Drake RL, Wayne V, Mitchell AWM, Tibbits R and Richardson R. Grays Atlas of Anatomy. 1st edition. Churchill Livingstone. 2007; 156-172.

Moore KL, Dalley AF and Agur AMR. Clinically Oriented Anatomy. 6thedition. Lippincott Williams & Wilkins. 2010; 265-307, 429-432, 446-449.

Moore KL, Dalley AF and Agur AMR. Essential Clinical Anatomy. 4thedition. Lippincott Williams & Wilkins. 2011; 152-174, 180-185, 245-248, 259-260.

Morton DA, Peterson KD and Albertine KH. Grays Dissection Guide for Human Anatomy. 2nd edition. Churchill Livingstone. 2006; 157-181.

Schuenke M., Schulte, E and Schumacher, U. Thieme Atlas of Anatomy: Neck and Internal Organs. 1st edition. Thieme. 2006; 190-216, 262-279, 306-315.