Abdominal surface anatomy
Abdominal surface anatomy can be described when viewed from in front of the abdomen in 2 ways:
- divided into 9 regions by two vertical and two horizontal imaginary planes
- divided into 4 quadrants by single vertical and horizontal imaginary planes
These regions and quadrants are of clinical importance when examining and describing pathologies related to the abdomen
Nine abdominal regions
Horizontal planes
The dividing planes are based on lines drawn between easily palpable bony points. The horizontal planes are also of importance as they provide useful landmarks on cross-sectional imaging. The two horizontal lines are:
- subcostal plane
-
transtubercular plane
- corresponds to a line uniting the two tubercles of the iliac crests
- upper border of the L5 vertebra and the confluence of the common iliac veins (i.e. IVC origin) lie on this plane
Vertical planes
The two vertical planes are similar on each side and follow a line joining the mid clavicular point to the mid inguinal point. It passes just lateral to the tip of the ninth costal cartilage, which is palpable as a distinct step along the costal margin. It roughly corresponds to the lateral border of the rectus abdominis muscle.
Surface anatomy
The above lines intersect and divide the abdomen into nine regions (clockwise from the top):
- epigastric region (epigastrium)
- left hypochondrium (LHC)
- left lumbar region (left flank)
- left iliac fossa (LIF)
- suprapubic (hypogastric) region
- right iliac fossa (RIF)
- right lumbar region (right flank)
- right hypochondrium (RHC)
- and in the center, the umbilical region
Four abdominal quadrants
Horizontal plane
The dividing plane is a horizontal line drawn through the umbilicus.
Vertical plane
The vertical line is down the midline of the body, overlying the linea alba from the xiphoid to the pubic symphysis.
Surface anatomy
The above lines intersect and divide the abdomen into four quadrants (clockwise from the top):
- right upper quadrant fossa (RUQ)
- right lower quadrant fossa (RLQ)
- left lower quadrant fossa (LLQ)
- left upper quadrant fossa (LUQ)
Related Radiopaedia articles
Anatomy: abdominopelvic
- skeleton of the abdomen and pelvis
- muscles of the abdomen and pelvis
- spaces of the abdomen and pelvis
- anterior abdominal wall
- posterior abdominal wall
-
abdominal cavity
-
peritoneum
- peritoneal ligaments
- mesentery
-
peritoneal spaces
-
supramesocolic space
-
right supramesocolic space
- right subphrenic space
-
right subhepatic space
- anterior right subhepatic space
- posterior right subhepatic space (Morison pouch)
-
lesser sac
- epiploic foramen (of Winslow)
- left supramesocolic space (left perihepatic space)
-
right supramesocolic space
- inframesocolic space
-
supramesocolic space
- inguinal canal (mnemonic)
- Hesselbach triangle
- scrotal sac
- retroperitoneum
-
peritoneum
- pelvic cavity
- perineum
- abdominal and pelvic viscera
- gastrointestinal tract
- spleen
- hepatobiliary system
-
endocrine system
-
adrenal gland
- adrenal vessels
- chromaffin cells
- variants
- pancreas
- organs of Zuckerkandl
-
adrenal gland
-
urinary system
-
kidney
- renal pelvis
- renal sinus
- avascular plane of Brodel
-
variants
- number
- fusion
- location
- shape
- ureter
- urinary bladder
- urethra
- embryology
-
kidney
- male reproductive system
-
female reproductive system
- vulva
- vagina
- uterus
- uterine tubes
- ovaries
- broad ligament (mnemonic)
- variant anatomy
- embryology
- blood supply of the abdomen and pelvis
- arteries
-
abdominal aorta
- inferior phrenic artery
- celiac artery
- superior mesenteric artery
- middle suprarenal artery
- renal artery (variant anatomy)
- gonadal artery (ovarian artery | testicular artery)
- inferior mesenteric artery
- lumbar arteries
- median sacral artery
-
common iliac artery
- external iliac artery
-
internal iliac artery (mnemonic)
- anterior division
- posterior division (mnemonic)
- variant anatomy
-
abdominal aorta
- portal venous system
- veins
- anastomoses
- arterio-arterial anastomoses
- portal-systemic venous collateral pathways
- watershed areas
- arteries
- lymphatics
- innervation of the abdomen and pelvis
- lumbar plexus
-
sacral plexus
- lumbosacral trunk
- sciatic nerve
- superior gluteal nerve
- inferior gluteal nerve
- nerve to piriformis
- perforating cutaneous nerve
- posterior femoral cutaneous nerve
- parasympathetic pelvic splanchnic nerves
- pudendal nerve
- nerve to quadratus femoris and inferior gemellus
- nerve to internal obturator and superior gemellus