Abdomen Anatomy 3 Lecture Quiz

Abdomen Anatomy 3 Lecture Notes

• Course: Block 1.2, 2024-2025
• Writer: Alaa Alessa
• Reviewer: Ghassan Al-Nasser
• Notes: 221-222-223
• Learning Outcomes: Students should be able to describe abdominal organs, understand their position, parts, and neurovascular supply.

Abdominal Organs (Content)

• Spleen: Not always part of digestive system, involved in reticuloendothelial and lymph.
• Pancreas: Composed of endocrine (producing hormones) and exocrine (producing enzymes) components.
• Liver: Essential digestive component.
• Gallbladder and Biliary system: Involved in digestive processes.
• Kidneys: Excretory function.
• Ureter: Excretory, transporting urine.
• Suprarenal gland: Endocrine function.

Abdominal Regions

• There are nine abdominal regions.
• Relevant anatomical regions for organs discussed:
  • Right Hypochondriac
  • Epigastric
  • Left Hypochondriac
  • Right Lumbar
  • Umbilical
  • Left Lumbar
  • Right Iliac
  • Hypogastric
  • Left Iliac

Spleen Detail

• Shape & Location: Ovoid, purplish, pulpy mass, size of a fist, located in the superolateral part of the left upper quadrant (LUQ), protected by the inferior thoracic cage.
• Vulnerability: Relatively delicate, considered the most vulnerable abdominal organ.
• Relations: Posteriorly: diaphragm; Anteriorly: stomach; Inferiorly: left colic flexure; Medially: left kidney.
• Size: Approximately 12 cm long, 7 cm wide, 1 inch thick, and weighs 7 ounces.

Spleen: Blood Supply & Lymphatics

• Arterial Supply: Splenic artery (largest branch of the celiac trunk)
• Venous Drainage: Splenic vein, formed by several tributaries from the hilum, joins the IMV and runs posterior to the body and tail of the pancreas before uniting with the SMV to form the hepatic portal vein.
• Lymphatics: Pass along the splenic vessels to pancreaticosplenic lymph nodes and celiac nodes.
• Nerves: Derived from celiac plexus, distributed along splenic artery branches, with vasomotor function.

Pancreas

• Location: Retroperitoneally, overlying and transversely crossing the bodies of the L1 and L2 vertebrae. Lies behind the stomach between duodenum (right) and spleen (left).
• Structure: Divided into head, neck, body, and tail.
• Functions: Endocrine (hormones, e.g., insulin, glucagon) and exocrine (enzymes for digestion).
• Blood supply: Branches of gastroduodenal and superior mesenteric arteries.
• Venous drainage: Via corresponding pancreatic veins.
• Lymphatics: Follow blood vessels; drain to superior mesenteric and celiac nodes.
• Nerves: Derived from the vagus and abdominopelvic splanchnic nerves via celiac and superior mesenteric plexuses.

Liver

• Size & Location: Largest gland in the body, lies mostly in the RUQ, deep to ribs 7-11 on the right and extends into the left upper quadrant.
• Protection: Protected by thoracic cage and diaphragm
• Associated structures:
  • Right side of gastric and pyloric areas
  • Superior part of duodenum
  • Lesser omentum
  • Gallbladder
  • Right colic flexure and transverse colon
  • Right kidney, suprarenal glands
• Gross surface features: Convex diaphragmatic (anterior, superior, posterior) surface and concave visceral (postero-inferior) surface
• Blood Supply: Hepatic portal vein( 75-80%), and hepatic artery(20-25%).
• Venous Drainage: Hepatic veins to inferior vena cava.
• Lymphatic Drainage: Lymph drains to the superior mesenteric and/or celiac lymph nodes
• Nerves: Derived from hepatic plexus, a component of the celiac plexus. Parasympathetic and Sympathetic fibers.

Gallbladder and Biliary System

• Bile Production: Continuous by liver.
• Concentration & Storage: Between meals, bile concentrates in the gallbladder.
• Ducts: Hepatic ducts from the liver combine to form the common hepatic duct, which joins with the cystic duct to form the common bile duct (CBD) that eventually empties into duodenum.
• Function: aids in emulsification of fats for digestion.
• Location: The body of the gallbladder lies anterior to the superior part of the duodenum, while its neck and cystic duct are immediately superior to the duodenum.

Kidneys/Ureters

• Location: Retroperitoneally on posterior abdominal wall. One on each side of the vertebral column, at the level of T12-L3 vertebrae.
• Shape, Size, & Color: Reddish-brown, each about 10 cm in length, 5 cm in width, and 2.5 cm in thickness.
• Relations: Superiorly kidneys are in contact with diaphragm.
• Renal Arteries/Veins: Renal arteries branch into segmented arteries. Renal veins will drain into inferior vena cava.
• Ureters: Muscular tubes carrying urine from kidneys to urinary bladder. These have three areas of constriction: where they join renal pelvis, where they cross the external iliac artery, and where they enter the bladder.

Suprarenal (Adrenal) Glands

• Location: Between superomedial aspect of the kidneys and the diaphragm, encompassed by connective tissue and perinephric fat.
• Connection to kidneys and diaphragm: Attached to the crura of the diaphragm.