Abdominal Quadrants and Regions: Organs, Structures, and Functions

Posted on Apr 30, 2024 in Biology

1. Define the Quadrants and Nine Regions of the Abdomen, and what organs, or structures are located in each.
   1. 1. Right Upper Quadrant (RUQ)
         1. Liver (Rt Lobe)
         2. Gallbladder
         3. Stomach – Pylorus
         4. Duodenum
         5. Pancreas – Head
         6. Rt Suprarenal Gland
         7. Rt Kidney
         8. Rt Colic, Hepatic Flexure
         9. Ascending Colon
         10. Rt Half Transverse Colon
      2. Left Upper Quadrant (LUQ)
         1. Liver (Lt Lobe)
         2. Spleen
         3. Stomach
         4. Left Kidney
         5. Pancreas – Body & Tail
         6. Lt Suprarenal Gland
         7. Lt Colic, Splenic Flexure
         8. Descending Colon – Superior
         9. Lt Half Transverse Colon
      3. Right Lower Quadrant (RLQ)
         1. Cecum – transition of ileum to Colon
         2. Appendix
         3. Most of Ileum
         4. Ascending Colon – Inferior
         5. Rt Ovary
         6. Rt Uterine Tube
         7. Rt Ureter
         8. Rt Spermatic Cord
         9. Uterus – if enlarged
         10. Bladder – if full
      4. Left Lower Quadrant (LLQ)
         1. Sigmoid Colon
         2. Descending Colon – Inferior
         3. Left Ovary
         4. Lt Ovary
         5. Lt Uterine Tube
         6. Lt Ureter
         7. Lt Spermatic Cord
         8. Uterus – if enlarged
         9. Bladder – if full

9 Regions:

Right Hypochondriac: Liver, R. Kidney, Gallbladder, Hepatic Flexure, Ascending and Transverse colon.

Epigastric: Liver, Stomach, Spleen, Duodenum, Pancreas, R. and L. Kidneys.

Left Hypochondriac: Liver, Stomach, Pancreas (tail), L. Kidney, Spleen, Splenic flexure

Right Lumbar: Ascending colon, Jejunum, R. Kidney

Umbilical: Duodenum, Jejunum, Transverse Colon, Ureters, Kidneys, Pancreas

Left Lumbar: Descending colon, Jejunum, L. Kidney

Right Inguinal: Appendix, Cecum, Ascending Colon, Ileum

Hypogastric (pubic): Bladder, Sigmoid colon, Ileum, Ovaries, Uterus, Ureters, Fallopian tubes, Spermatic cords, Prostate, Rectum

Left Inguinal: Sigmoid colon, Descending colon, Ileum

2. Describe the Peritoneum

-The Peritoneum is a continuous, glistening, and slippery transparent serous membrane. It lines the abdominopelvic cavity and invests the viscera. The peritoneum consists of two continuous layers: the Parietal Peritoneum, which lines the internal surface of the abdominopelvic wall, and the Visceral Peritoneum, which invests viscera such as the stomach and intestines. In places, the Peritoneum extends from the Organs back to the Abdominal Wall; “Mesenteries”, “Ligaments”, and “Omenta”

– Intraperitoneal organs are almost completely covered with visceral peritoneum (e.g., the stomach and spleen). Intraperitoneal in this case does not mean inside the peritoneal cavity (although the term is used clinically for substances injected into this cavity). Intraperitoneal organs have conceptually, if not literally, invaginated into the closed sac, like pressing your fist into an inflated balloon (see the discussion of potential spaces in the Chapter 1, Overview and Basic Concepts).

 –Extraperitoneal, Retroperitoneal, and Subperitoneal organs are also outside the peritoneal cavity—external to the parietal peritoneum—and are only partially covered with peritoneum (usually on just one surface). Retroperitoneal organs such as the kidneys are between the parietal peritoneum and the posterior abdominal wall and have parietal peritoneum only on their anterior surfaces (often with a variable amount of intervening fat). Similarly, the subperitoneal urinary bladder has parietal peritoneum only on its superior surface.

3. What are the Anatomical Structures of the Foregut and their blood and nerve supplies?
   2. Abdominal Esophagus
   3. Stomach
   4. Proximal Duodenum
   5. Spleen
   6. Liver
   7. Gall Bladder
   8. BLOOD/NERVE: Celiac Trunk/CN X Vagus

4. What are the Anatomical Structures of the Midgut and their blood and nerve supplies?
   9. Distal Duodenum
   10. Jejejenum
   11. Ileum
   12. Cecum
   13. Ascending Colon
   14. 2/3 of Transverse Colon
   15. BLOOD/NERVE: Superior Mesenteric Artery/CN X Vagus

5. What are the Anatomical Structures of the Hindgut and their blood and nerve supplies?
   16. Distal 1/3 of Transverse Colon
   17. Descending Colon
   18. Sigmoid Colon
   19. Rectum
   20. BLOOD /NERVE: Inferior Mesenteric Artery/Sacral Segments S2, S3, S4

6. What are the Functions of the Stomach?
   21. Temporary storage for food, which passes from the esophagus to the stomach where it is held for 2 hours or longer
   22. Mixing and breakdown of food by contraction and relaxation of the muscle layers in the stomach
   23. Digestion of food

7. What are the Functions of the Liver?
   24. Bile synthesis and secretion.
   25. Nutrient and Drug metabolism.
   26. Production of Cholesterol.
   27. Production of Blood Clotting Factors.
   28. Clearance of bilirubin.
   29. Synthesis of plasma proteins.
   30. Secretion and modification of hormones.
   31. Storage of essential molecules.
   32. Removal of aged blood cells.
   33. Detoxification.

8. What are the Functions of the Gall Bladder?
   34. Store, concentrate, and excrete Bile into the Duodenum