In the digestive system, the contains lobules with sinusoids (lined with macrophages) that lead to a central venous structure. a. liver b. spleen c. stomach d. pancreas
The correct answer and explanation is:
The correct answer is a. liver.
The liver is an organ in the digestive system that contains lobules, which are its functional units. Each lobule consists of hepatocytes (liver cells) arranged around a central vein. The blood supply within the lobules passes through specialized blood vessels known as sinusoids. These sinusoids are capillary-like structures that allow for the exchange of substances between the blood and liver cells.
Sinusoids are lined with endothelial cells and Kupffer cells, which are specialized macrophages. These Kupffer cells play a critical role in the immune response by filtering out bacteria, dead cells, and other foreign substances from the blood. The sinusoids also provide a unique structure in which blood from the portal vein and hepatic artery is mixed before it drains into the central venous system.
The liver’s lobules are crucial for its functions, such as detoxifying chemicals, producing bile, storing vitamins and minerals, and synthesizing proteins like albumin and clotting factors. The blood in the sinusoids is filtered by the hepatocytes, which metabolize nutrients, detoxify harmful substances, and store glucose as glycogen. The filtered blood is eventually collected into central veins, which merge to form larger veins that drain into the hepatic veins and ultimately into the inferior vena cava, which returns blood to the heart.
The structure of the liver, with its lobules, sinusoids, and macrophages, is designed to optimize its vital functions in digestion, metabolism, and immune defense. The liver is the only organ in the digestive system with this specialized architecture that allows for the processing of a wide range of substances entering the body through the bloodstream.