Abdominal Regions, Hepatic Anatomy & Exam Guide

• Diagram is a 3 × 3 “tic-tac-toe” grid.
• Landmark supplied on exam: Umbilical region (center).
– Superior to it → Epigastric region.
– Inferior to it → Hypogastric / Suprapubic region.
• Epigastric flanks (R & L) → Right and Left Hypochondriac regions.
• Umbilical flanks (R & L) → Right and Left Lumbar (flank) regions—named for underlying lumbar vertebrae.
• Hypogastric flanks (R & L) → Right and Left Iliac / Inguinal regions—named for the iliac part of the pelvic bone.

Celiac Trunk

• Must recall the three primary branches:

  1. Common hepatic artery

  2. Left gastric artery

  3. Splenic artery
    • Exam style: multiple-choice asking either “Which is a branch?” or “Which is NOT a branch?”.
    • Location image: trunk with its 1-2-3 branches will not be labelled, only queried in MCQ.

Gastric Artery Anastomosis

• Left gastric (direct from celiac) and Right gastric (branch of proper hepatic) meet along the lesser curvature of the stomach.
• Blood supply to lesser curvature is solely from this anastomosis.
• Question expected on: “How do these connect?”—MCQ, not diagram.
• Trace: Celiac → Common hepatic → Proper hepatic → Right gastric → joins left gastric.

Portal Vein Formation

• Know the two tributaries that merge posterior to neck of pancreas to form portal vein:
– Splenic vein
– Superior mesenteric vein (SMV)
• Question type: fill-in-the-blank / multiple-choice.
• Portal V.=Splenic V.+SMV\text{Portal V.} = \text{Splenic V.} + \text{SMV}

Bile Production, Storage & Role

• Produced by hepatocytes in liver.
• Stored & concentrated in gallbladder (GB) until needed.
• Function: emulsifies dietary fats in small intestine.
• Volume (FYI only) ≈ 900  mL900\;\text{mL} daily.
• Exam will ask: “Where is bile produced?” / “Where is it stored?” / “What does bile do?”

Liver Ligaments

• Falciform ligament
– Suspends liver from diaphragm & anterior abdominal wall; anatomically divides R & L lobes on diaphragmatic surface.
– Appears as echogenic band on US; students must label it on an image.
• Ligamentum teres (Round ligament)
– Caudal free edge of falciform; remnant of fetal left umbilical vein.
– Seen as round echogenic focus on inferior surface—will be labeled.
• Ligamentum venosum
– Remnant of ductus venosus; course between left lobe & caudate lobe toward IVC.
– Must recognize on long-axis & transverse US images.
• Both ligaments to be tested with MCQs and figure labelling.

Liver Function Test Enzymes

• Key intracellular enzymes: AST (aspartate aminotransferase) & ALT (alanine aminotransferase).
• Elevated in hepatocellular injury (hepatitis, alcohol, tumor, etc.).
• Exam will contain MCQ: “Which combination represents liver enzymes?” → pick AST & ALT.
• Pathologic implications discussed next lecture (not testable yet).

Portal Triad vs Hepatic Veins (US Recognition)

• Portal triad = Portal vein (PV) + Hepatic artery (HA) + Common bile duct (CBD).
• PV characteristics: intrasegmental, centrally located, echogenic walls on US.
• Hepatic veins: intersegmental, drain toward IVC, no echogenic walls.
• Distinction is a common ID question.

Segmental Anatomy of Liver

First-Order Division

• Liver→Right lobe+Left lobe\text{Liver} \rightarrow \text{Right lobe} + \text{Left lobe} by middle hepatic vein/IVC axis.

Second-Order Division

• Right lobe → Right anterior & Right posterior (split by right hepatic vein).
• Left lobe → Left medial & Left lateral (split by left hepatic vein).

Third-Order (Couinaud)

• Each second-order sector subdivided into superior (segments 7-8-2-4A) and inferior (segments 6-5-3-4B) halves.
• Segment map (clockwise from caudate):
– I = Caudate (posterior to porta)
– II = Left lateral superior
– III = Left lateral inferior
– IVa = Left medial superior
– IVb = Left medial inferior
– V = Right anterior inferior
– VI = Right posterior inferior
– VII = Right posterior superior
– VIII = Right anterior superior
• Students must:
– Number a cartoon liver (1 ↔ 8) on exam.
– Complete a matching table (segments ↔ names). Worth 1 point total.

Caudate Lobe & IVC Relationship

• Caudate lobe lies between left lobe and groove for IVC.
• Image ID: left lobe → caudate → IVC (posterior).
• Caudate frequently labelled on posterior view diagram.

Required Image-Based Labelling

• Exam will show stripped diagrams (letters instead of names). Student duties:
– Abdominal surface regions grid (match A–I).
– Hepatic segment cartoon (numbers).
– Liver posterior view (caudate, IVC, left lobe).
– Portal triad vs hepatic veins cross-section.
– Falciform ligament, ligamentum teres, ligamentum venosum on US.
– Two additional kidneys/retroperitoneum image (from 3-min video in bulletin)—know adjacent anatomy.

Miscellaneous Exam Mechanics

• Entire test delivered in Populi; 2-hour time limit; window open until Sunday\text{Sunday}.
• Question types:
– Image labelling (drag-drop or typed).
– Matching lists.
– Standard MCQ (single correct) / “Which is NOT”.
– Fill-in-the-blank (with drop-down choices).
• Multi-part matching counts only 1 point total if any mistakes.
• Attendance check via Zoom around 10:3010{:}30 before release; optional early log-off afterward.

Study & Review Advice

• Watch the 3-minute kidney/retroperitoneum video posted on bulletin board (exam images derive from it).
• Rehearse liver segment numbering until automatic.
• Differentiate portal vein vs hepatic veins by wall echogenicity and location.
• Memorize small but key fact lists (AST/ALT, triad components, celiac branches, portal-vein formation, bile pathway).
• Expect ligaments & vascular landmarks to appear both as MCQ text and as image labels.