What is the difference between the hypogastric (pubic) region and the suprapubic region, and what are the nine anatomical regions of the abdomen?

Anatomical Distinction Between Hypogastric and Suprapubic Regions

The hypogastric region and suprapubic region refer to the same anatomical area—the lower central portion of the abdomen immediately above the pubic bone. These terms are used interchangeably in clinical practice, with "suprapubic" being more commonly used in ultrasound and procedural contexts 1.

Terminology Clarification

• Suprapubic literally means "above the pubic bone" and is the preferred term when describing the pelvic ultrasound window, where the probe is placed "immediately cephalad to the pubic bone" 1
• Hypogastric is the formal anatomical term for this same region in the nine-region classification system of the abdomen 2
• Both terms describe the central lower abdominal area that overlies the bladder and pelvic organs 1

Clinical Context

• In emergency ultrasound, this area is referred to as the "pelvic" or "suprapubic view" for visualizing the bladder and detecting free fluid in the most dependent peritoneal space 1
• The suprapubic/hypogastric region corresponds to the pelvic inlet area and is critical for examining pelvic pathology in women with abdominal pain 2

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The Nine Regions of the Abdomen

The abdomen is divided into nine regions using two horizontal and two vertical planes:

Horizontal Planes

• Subcostal plane: Passes through the inferior margin of the 10th costal cartilage
• Intertubercular (transtubercular) plane: Passes through the iliac tubercles (approximately at the level of L5 vertebra)

Vertical Planes

• Two midclavicular lines: Extend from the midpoint of the clavicle down through the mid-inguinal point

The Nine Regions (from superior to inferior, left to right):

Upper Row

1. Right hypochondriac region (right upper)
2. Epigastric region (central upper)
3. Left hypochondriac region (left upper)

Middle Row

1. Right lumbar (lateral) region (right middle)
2. Umbilical region (central middle)
3. Left lumbar (lateral) region (left middle)

Lower Row

1. Right iliac (inguinal) region (right lower)
2. Hypogastric (suprapubic/pubic) region (central lower)
3. Left iliac (inguinal) region (left lower)

Clinical Relevance

• The nine-region system provides more precise anatomical localization than the simpler four-quadrant method 2
• The hypogastric region specifically contains the bladder, uterus (in females), and sigmoid colon, making it critical for evaluating pelvic pathology 1, 2
• Regional lymph node drainage patterns vary by abdominal region, with the hypogastric area draining to internal iliac, obturator, and external iliac nodes 1

Common Pitfall

• Do not confuse the hypogastric region (the anatomical area) with the hypogastric plexus (a nerve plexus located at the lumbosacral region below the aortic bifurcation) 3—these are entirely different structures despite sharing similar nomenclature