Step by Step
Grid
The 3×3 grid structure
The abdomen is divided into nine regions using two vertical and two horizontal lines, forming a 3×3 grid.
Top
Top row — hypochondriac and epigastric regions
The top row consists of the right hypochondriac (liver, gallbladder), epigastric (stomach, liver), and left hypochondriac (spleen, stomach) regions.
Mid
Middle row — lumbar and umbilical regions
The middle row consists of the right lumbar/lateral (ascending colon), umbilical (transverse colon, small intestine), and left lumbar/lateral (descending colon) regions.
Bot
Bottom row, and the four-quadrant clinical shorthand
The bottom row consists of the right iliac/inguinal (cecum, appendix), hypogastric/pubic (bladder, uterus), and left iliac/inguinal (sigmoid colon) regions. McBurney's point, associated with appendicitis, is located in the right iliac region. Clinically, a simpler four-quadrant system (RUQ, LUQ, RLQ, LLQ) is often used as shorthand instead of all nine regions.
A patient presenting with pain that started near the umbilical region and later migrated to the right iliac region is showing the classic pattern of appendicitis — early, poorly localized pain near the umbilicus, followed by pain that sharpens and localizes to McBurney's point as the inflammation progresses.
Applied Walkthrough
1
A patient reports abdominal pain that started as a vague ache near the belly button and has since become a sharp, localized pain in the lower right side of the abdomen.
2
Ask: what does this specific pattern of pain migration suggest? This is the classic presentation of appendicitis — early pain is often poorly localized to the umbilical region (since the appendix's visceral pain fibers refer there), while later, more localized pain reflects irritation of the parietal peritoneum directly overlying the inflamed appendix in the right iliac region, at McBurney's point.
3
Contrast: if the patient instead had pain concentrated from the start in the right hypochondriac region, that would point toward a gallbladder or liver issue instead, given the organs housed specifically in that upper region.
4
This kind of region-to-organ mapping — recognizing that pain location and pain pattern together can suggest a specific underlying organ or condition — is exactly why the nine-region system (and its four-quadrant clinical shorthand) exists in the first place.
Exam Application
Exams test correctly mapping each of the nine regions to its contents (hypochondriac: liver/spleen, epigastric: stomach, lumbar: ascending/descending colon, umbilical: small intestine, iliac: cecum/appendix/sigmoid colon, hypogastric: bladder), the location of McBurney's point (right iliac region), and translating between the nine-region system and the simpler four-quadrant clinical shorthand.
⚠ Common Trap
The most common trap is confusing the middle-row lumbar/lateral regions (ascending and descending colon) with the bottom-row iliac regions (cecum, appendix, sigmoid colon) — both involve parts of the colon, but at different points along its course, and appendicitis pain specifically localizes to the right iliac region, not the right lumbar region.
✓ Quick Self-Check
1. How many regions divide the abdomen, and how are they arranged?
Nine regions, arranged in a 3×3 grid using two vertical and two horizontal lines.
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2. What organs are found in the epigastric region?
The stomach and liver.
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3. What is found in the umbilical region, and why is this clinically significant for appendicitis?
The small intestine and transverse colon; early appendicitis pain often starts here before localizing to the right iliac region.
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4. Where is McBurney's point located, and what condition is it associated with?
The right iliac region; it's associated with appendicitis.
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5. What is the simpler four-quadrant system used clinically instead of the nine regions?
RUQ (right upper quadrant), LUQ (left upper quadrant), RLQ (right lower quadrant), and LLQ (left lower quadrant).
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