Video Transcript
The diagram provided shows the
human gastrointestinal tract. Where is the duodenum? (A) At the beginning of the large
intestine. (B) Between the stomach and the
middle of the small intestine. (C) Just below the rectum. Or (D) between the small intestine
and the large intestine.
This question is asking us to
identify where the duodenum is located in the human gastrointestinal tract, which is
otherwise simply known as the digestive tract, and provides us with a diagram that
shows a part of it. Let’s take a quick tour of the
route that food takes through the gastrointestinal tract so that we can work out
which part is the duodenum.
Initially, food is placed into the
mouth and then travels down a tubelike organ called the esophagus to reach the first
organ that we can see on the diagram, the stomach. In the stomach, food is mixed with
gastric juices to form a substance called chyme, and protease enzymes start to break
down the proteins in food. From the stomach, food passes into
the small intestine, which is made up of three main parts. First, food passes into the
duodenum then into the jejunum and finally into the ileum.
The small intestine is where the
majority of protein, carbohydrate, and lipid breakdown occurs and where their
constituent subunits are absorbed to be transported to the body cells as
required. After the small intestine, food
passes into the large intestine, which ends in a region called the rectum, where
undigested food is stored as feces before its egestion from the body through the
anus.
By looking at our annotated
diagram, we can see that the duodenum is the first part of the small intestine. So the correct answer to the
question must be (B). The duodenum is located between the
stomach and the middle of the small intestine.
