The correct option for the blood vessels that supply the mammalian alimentary canal is
B: coeliac artery, anterior mesenteric artery, and posterior mesenteric artery. Let's break down why this is the correct answer and why the other options are incorrect.
Explanation of the Correct Answer
-
Understanding the Alimentary Canal: The alimentary canal, also known as the digestive tract, includes organs such as the esophagus, stomach, small intestine, and large intestine. These organs require a rich blood supply to deliver nutrients and oxygen and to remove waste products.
-
Key Blood Vessels:
- Coeliac Artery: This artery branches off from the abdominal aorta and supplies blood to the stomach, liver, spleen, and parts of the pancreas and duodenum. It is a major vessel that plays a crucial role in supplying the upper part of the alimentary canal.
- Anterior Mesenteric Artery: This artery supplies blood to the small intestine (except for the duodenum) and the proximal part of the large intestine. It branches off from the abdominal aorta and is essential for the vascularization of the midgut.
-
Posterior Mesenteric Artery: This artery supplies blood to the distal part of the large intestine. It also branches from the abdominal aorta and is important for the vascularization of the hindgut.
-
Why Option B is Correct: The combination of the coeliac artery, anterior mesenteric artery, and posterior mesenteric artery covers the entire alimentary canal from the stomach to the large intestine, ensuring that all parts receive adequate blood supply.
Why the Other Options are Incorrect
- Option A: Segmented artery, hepatic artery, and coeliac artery:
- Segmented artery: This term is not commonly used in the context of the blood supply to the alimentary canal. It may refer to arteries that supply segmented structures, but it is not a recognized vessel in this context.
-
Hepatic artery: While the hepatic artery does supply the liver, it is not one of the primary vessels supplying the alimentary canal directly. The liver is involved in digestion but is not part of the alimentary canal itself.
-
Option C: Coeliac artery, segmental artery, and hepatic artery:
-
Similar to Option A, the term "segmental artery" is not relevant in this context. The hepatic artery is again included, which does not directly supply the alimentary canal.
-
Option D: Hepatic artery, anterior mesenteric artery, and posterior mesenteric artery:
- While the anterior and posterior mesenteric arteries are correctly included, the hepatic artery does not supply the alimentary canal directly. It primarily supplies the liver, which is an accessory organ of digestion.
Summary of Key Points
- The coeliac artery, anterior mesenteric artery, and posterior mesenteric artery are the three main blood vessels supplying the mammalian alimentary canal.
- The coeliac artery supplies the upper digestive organs, while the mesenteric arteries supply the small and large intestines.
- Other options included incorrect or irrelevant terms that do not pertain to the direct blood supply of the alimentary canal.
Revision Summary
- The alimentary canal is supplied by three main arteries: coeliac, anterior mesenteric, and posterior mesenteric.
- The coeliac artery supplies the stomach and upper digestive organs.
- The anterior mesenteric artery supplies the small intestine and part of the large intestine.
- The posterior mesenteric artery supplies the distal large intestine.