Abdominal Cavity and Peritoneal Anatomy - Study Notes

  1. Abdominal Wall and Surface Landmarks
    Key landmarks include linea alba, abdominal muscles (obliques, transversus abdominis, rectus abdominis), inguinal region (ligament, canal), and pubic symphysis, with the sternum as a superior boundary.

  2. Body Cavities

    • Ventral Cavities: Thoracic and abdominopelvic, separated by the diaphragm.

    • Dorsal Cavities: Cranial and spinal.

  3. Normal Anatomy: Abdomen, Thorax, and Pelvis

    • Thoracic: Heart.

    • Abdominal: Liver, pancreas, stomach, small and large intestines.

    • Pelvic: Seminal vesicles, prostate, bladder, vagina, uterus, cervix, fallopian tubes, ovaries, rectum, hip joint boundaries.

  4. Abdominal Quadrants and Regions

    • Quadrants: RUQ, LUQ, RLQ, LLQ.

    • Regions: Flanks (Rt/Lt).

    • Purpose: Localize pathology and guide clinical assessment.

  5. Peritoneum and Omenta

    • Peritoneum: Serous membrane lining the abdominal cavity, comprising visceral (organ cover) and parietal (cavity lining) layers.

    • Lesser Omentum (gastrohepatic omentum): Connects liver to lesser curvature of stomach/duodenum.

    • Greater Omentum (omental majus): Apron-like fold from stomach, protecting intestines.

    • Mesentery: Peritoneal fold attaching small intestine to posterior abdominal wall, carrying vessels/nerves.

  6. Peritoneal Cavity and Related Structures

    • Spaces: Subdiaphragmatic, subhepatic, anterior cul-de-sac (vesicouterine pouch), posterior cul-de-sac (pouch of Douglas).

    • Sacs: Greater sac (main cavity) and Lesser sac (omental bursa, posterior to stomach).

    • Foramen of Winslow (Epiploic Foramen): Connects greater and lesser sacs, allowing communication of peritoneal spaces.

  7. Peritoneal vs Retroperitoneal Organs

    • Peritoneal (Intraperitoneal): Liver (except bare area), gallbladder, spleen (except hilum), stomach, most intestines, ovaries.

    • Retroperitoneal: Kidneys, ureters, adrenal glands, pancreas, great vessels (aorta, IVC), urinary bladder, uterus (portions), prostate, ascending/descending colon, most duodenum, lymph nodes, somatic nerves.

  8. Retroperitoneum: Spaces and Compartments

    • Pararenal Spaces: Anterior pararenal (pancreas, duodenum, colons), Perirenal (adrenals, kidneys, ureters, great vessels), Posterior pararenal (blood, lymph nodes, iliac fossa).

    • Compartments: Psoas major, quadratus lumborum (lumbar region), iliacus.

  9. Retroperitoneal Vasculature

    • Major Vessels (Aorta & IVC branches): Celiac trunk (common hepatic, left gastric, splenic arteries), SMA, IMA, renal arteries/veins, gonadal arteries/veins, lumbar arteries/veins, inferior phrenic arteries, suprarenal arteries, common iliac arteries/veins, middle sacral artery.

    • Relationships: IVC and aorta are intimately related to duodenum, bile ducts, pancreas, stomach, liver, spleen, kidneys, and major visceral branches.

  10. Abdominal Viscera: Overview

    • Digestive Tract: Esophagus (cardiac region), stomach (cardia, fundus, body, pyloric region), small intestine (duodenum, jejunum, ileum), large intestine (cecum, appendix, ascending, transverse, descending, sigmoid colon, rectum, anal canal).

    • Accessory Organs: Liver (left/right, caudate/quadrate lobes, stabilized by ligaments, bare area, porta hepatis), gallbladder (fundus, body, neck, cystic duct), spleen (splenic artery/vein).

    • Pancreas: Largely retroperitoneal, head in duodenal C-loop, uncinate process around SMA/SMV.

  11. Portal Triad and Hepatic Blood Supply

    • Components: Hepatic artery proper, portal vein, common bile duct, all within the hepatoduodenal ligament.

    • Portal Vein: Formed by splenic vein and SMV, enters liver at porta hepatis.

  12. Pelvic Anatomy

    • Female: Uterus, cervix, fallopian tubes, ovaries, vagina, bladder (anterior to uterus), urethra.

    • Male: Prostate, seminal vesicles (near bladder and rectum).

  13. Peritoneal Spaces with Free Fluid (Ascites)

    • Fluid accumulates in dependent spaces: subdiaphragmatic, subhepatic, anterior cul-de-sac, posterior cul-de-sac.

  14. Summary of Key Structures and Relationships

    • Peritoneal: Liver, gallbladder, spleen, stomach, most intestines, ovaries.

    • Retroperitoneal: Kidneys, ureters, adrenal glands, pancreas, great vessels, urinary bladder, uterus (portions), prostate, ascending/descending colon, most duodenum, lymph nodes, somatic nerves.

    • Major Vasculature: Celiac trunk, SMA, IMA, hepatic, gastric, splenic, gastroduodenal, portal, hepatic, renal, gonadal, iliac, lumbar, phrenic vessels.

    • Portal Triad: Hepatic artery proper, portal vein, common bile duct within hepatoduodenal ligament.

    • Foramen of Winslow: Connects greater and lesser sacs.

    • Omenta/Mesenteries: Provide vascular and neural supply.

    • Retroperitoneal Spaces: Anterior pararenal, perirenal, posterior pararenal spaces, and compartments (psoas, quadratus lumborum, iliacus).