Weekly Liver Histology and Physiology Exam - March 7, 2026 (Section A: MCQs) | MCQ Quiz | OmpathStudy Kenya

Question 1

What is the structural unit of the liver characterized by a hexagonal shape with a central vein in the middle?

Accepted Answer

Lobule — The lobule is the structural unit of the liver, typically hexagonal with a central vein at its center and portal triads at the periphery.

Question 2

Which structure sits at the center of the hepatic acinus?

Accepted Answer

The axis formed by the portal triad vessels — The acinus is the functional unit based on microcirculation, centered on the line connecting two portal triads.

Question 3

Which of the following is NOT part of the portal triad?

Accepted Answer

Central vein — The portal triad contains a bile duct, a branch of the hepatic artery, and a branch of the portal vein. The central vein is a tributary of the hepatic vein.

Question 4

Which acinar zone receives the highest concentration of oxygenated blood?

Accepted Answer

Zone 1 — Zone 1 (periportal) is closest to the hepatic artery and portal vein branches, receiving the best oxygenation.

Question 5

Damage from phosphorus poisoning typically affects which zone first?

Accepted Answer

Zone 1 — Zone 1 (periportal) is the first zone reached by blood coming from the portal triad and is specifically affected by phosphorus poisoning and eclampsia.

Question 6

Which zone is most susceptible to ischemic injury and hypoxia?

Accepted Answer

Zone 3 — Zone 3 is the furthest from the blood supply (centrilobular), making it the first to suffer in hypoxic conditions.

Question 7

The central vein is considered a tributary of which vessel?

Accepted Answer

Hepatic vein — Blood flows from the portal triads through sinusoids into the central vein, which then drains into the hepatic veins.

Question 8

What is the functional unit of the liver based on microcirculation called?

Accepted Answer

Hepatic acinus — The hepatic acinus is defined by its microcirculatory properties rather than purely anatomical borders.

Question 9

Where are the portal triads located in a classic hepatic lobule?

Accepted Answer

At the periphery/corners — In the hexagonal lobule model, portal triads are located at the peripheral corners.

Question 10

Which zone is located mid-way between the portal triad and the central vein?

Accepted Answer

Zone 2 — Zone 2 is the midzonal region located between the periportal (Zone 1) and centrilobular (Zone 3) areas.

Question 11

Eclampsia typically involves damage to which zone of the liver acinus?

Accepted Answer

Zone 1 — Zone 1 (periportal) is the primary site of injury in conditions like phosphorus poisoning and eclampsia.

Question 12

Which structure is responsible for carrying bile away from the liver lobule?

Accepted Answer

Bile duct — The bile duct, part of the portal triad, carries bile produced by hepatocytes towards the larger biliary tree.

Question 13

The axis of the hepatic acinus is formed by which vessels?

Accepted Answer

Tributaries of the hepatic artery and portal vein — The acinus is centered on the terminal branches of the portal vein and hepatic artery.

Question 14

What happens to the oxygen gradient as blood moves from Zone 1 to Zone 3?

Accepted Answer

Oxygen levels decrease — Oxygen levels are highest in Zone 1 (periportal) and lowest in Zone 3 (centrilobular).

Question 15

Which zone would be most impacted by congestion in the hepatic vein?

Accepted Answer

Zone 3 — Zone 3 surrounds the central vein; therefore, back-pressure from the hepatic vein affects Zone 3 most significantly.

Question 16

The term 'Periportal' refers to which zone?

Accepted Answer

Zone 1 — Zone 1 is periportal, meaning it is located immediately around the portal triads.

Question 17

In the context of liver histology, what does 'Centrilobular' refer to?

Accepted Answer

The area surrounding the central vein — Centrilobular refers to the area closest to the central vein (Zone 3).

Question 18

Which of the following is found in a portal triad?

Accepted Answer

Bile duct — The classic portal triad contains a branch of the portal vein, hepatic artery, and bile duct.

Question 19

If a patient is exposed to a toxin that enters via the blood, which zone encounters the highest concentration first?

Accepted Answer

Zone 1 — Zone 1 is the first to be exposed to everything entering via the portal vein and hepatic artery.

Question 20

Which description best matches the liver acinus?

Accepted Answer

Diamond-shaped functional unit — The acinus is often described as a diamond or oval shaped unit based on the blood supply from the portal axis to the central veins.

Question 21

The oxygenation status of Zone 1 is described as:

Accepted Answer

Best — Zone 1 receives the most oxygenated blood from the hepatic artery.

Question 22

Phosphorus poisoning is a characteristic pathology of which zone?

Accepted Answer

Zone 1 — Phosphorus poisoning is a classic example of a Zone 1 (periportal) injury.

Question 23

The hepatic artery provides what to the liver?

Accepted Answer

Oxygenated blood — The hepatic artery delivers oxygen-rich blood to the liver tissues.

Question 24

Where does blood from the portal vein and hepatic artery mix?

Accepted Answer

Hepatic sinusoids — The sinusoids are the capillary-like spaces where oxygenated and deoxygenated blood mix before reaching the central vein.

Question 25

Which zone is most distal to the portal triad?

Accepted Answer

Zone 3 — Zone 3 is the centrilobular zone, furthest from the portal triad's arterial and venous input.

Question 26

In a hexagonal lobule, how many portal triads are usually located at the corners?

Question 27

Which zone is likely to show the first signs of regeneration?

Accepted Answer

Zone 1 — Due to high oxygen and nutrient levels, Zone 1 is highly metabolically active and resilient in various contexts.

Question 28

Which of the following best defines Zone 2?

Accepted Answer

Midzonal — Zone 2 is the intermediate area between Zone 1 and Zone 3, known as midzonal.

Question 29

Which vessel drains blood from the liver into the inferior vena cava?

Accepted Answer

Hepatic vein — Central veins aggregate into hepatic veins, which then drain into the IVC.

Question 30

Zone 3 injury is commonly associated with which of the following?

Accepted Answer

Ischemia — Zone 3 is the most sensitive to ischemia due to being the last to receive oxygen.

Question 31

The portal vein carries blood from which organs to the liver?

Accepted Answer

Gastrointestinal tract and spleen — The portal vein brings nutrient-rich, deoxygenated blood from the GI tract and spleen to the liver.

Question 32

Which of the following is a component of the 'portal canal' or 'portal tract'?

Accepted Answer

Portal triad — The portal canal contains the portal triad (bile duct, hepatic artery, portal vein).

Question 33

Acinar zones are numbered 1 through 3 based on:

Accepted Answer

Order of blood contact/oxygenation — Zones are numbered based on the sequence in which blood flows through them from the portal triad (1) to the central vein (3).

Question 34

Which zone has the least amount of cytochrome P450 activity typically?

Accepted Answer

Zone 1 — While not explicitly in the text snippet provided, clinically Zone 3 often has higher P450 activity for metabolism; however, Zone 1 is the most oxygenated and metabolically active for processes like oxidative metabolism.

Question 35

Blood in the sinusoids flows towards which structure?

Accepted Answer

Central vein — Blood flows from the periphery (portal triad) toward the center (central vein).

Question 36

If a hepatic lobule were a wheel, what would be the 'hub'?

Accepted Answer

Central vein — In the lobule model, the central vein is the center (hub) and the portal triads are on the rim.

Question 37

The microcirculatory unit of the liver is the:

Accepted Answer

Acinus — The acinus is the functional unit defined by microcirculation.

Question 38

Bile flows in which direction relative to blood?

Accepted Answer

Opposite direction — Blood flows towards the central vein; bile flows through canaliculi toward the portal triad (counter-current).

Question 39

Which zone is most affected by viral hepatitis (non-specific)?

Accepted Answer

Zone 1 — While hepatitis can be diffuse, early involvement often targets Zone 1 due to blood flow dynamics, though Zone 3 is often cited for toxins.

Question 40

The structural unit 'Hepatic Lobule' focuses on:

Accepted Answer

Vascular drainage — The hepatic lobule is centered around the central vein, emphasizing the drainage of blood.

Question 41

Which pathology is associated with Zone 2?

Accepted Answer

Yellow Fever — Yellow fever is a classic (though rare in exams) example of midzonal (Zone 2) necrosis; note: the provided text focuses on Zone 1 and 3.

Question 42

What is the primary characteristic of the Liver Acinus model?

Accepted Answer

It emphasizes blood supply and oxygenation — The acinus model is centered on the blood supply providing a gradient of oxygen and nutrients.

Question 43

The portal triad vessels are enclosed in which type of tissue?

Accepted Answer

Connective tissue — The portal tracts/triads are held together by a connective tissue stroma.

Question 44

What is the vascular arrangement that allows hepatocytes and blood to interact?

Accepted Answer

Sinusoids — Sinusoids are specialized fenestrated capillaries in the liver where exchange occurs.

Question 45

Which zone is closest to the portal triad?

Accepted Answer

Zone 1 — Zone 1 is the periportal zone, immediately surrounding the portal triad.

Question 46

Comparing Zone 1 and Zone 3, Zone 3 has:

Accepted Answer

Less oxygen — As blood flows from 1 to 3, hepatocytes in Zone 1 extract oxygen, leaving Zone 3 with the least amount.

Question 47

Which of the following is true regarding portal triads?

Accepted Answer

They are located at the corners of the lobule — Portal triads are located at the periphery or corners of the traditionally hexagonal lobule.

Question 48

Zone 1 is also known as:

Accepted Answer

Periportal — Periportal and Zone 1 are synonymous in the acinar model.

Question 49

Central vein is a tributary of the hepatic vein. This means blood flows:

Accepted Answer

From central vein to hepatic vein — Central veins collect blood from sinusoids and deliver it into hepatic veins.

Question 50

Which zone is the 'last' to receive blood?

Accepted Answer

Zone 3 — Zone 3 is the centrilobular area, which is the final area blood passes through before entering the central vein.

Weekly Liver Histology and Physiology Exam - March 7, 2026 (Section A: MCQs) | MCQ Quiz | OmpathStudy Kenya

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