Final answer:
The intestinal glands of the small intestine are tubular glands within the mucosa and submucosa, known as crypts of Lieberkühn, which secrete intestinal juice to aid digestion.
Step-by-step explanation:
The intestinal glands, also known as the crypts of Lieberkühn, are tubular glands located in the mucosa between the villi of the small intestine. These glands secrete intestinal juice, a slightly alkaline fluid composed of water and mucus. This secretion aids digestion and provides lubrication, making it easier for chyme to pass through the intestines. Additionally, these glands contribute to the overall absorptive surface area of the intestinal lining.
Mucosa-associated lymphoid tissue (MALT), including Peyer's patches, is involved in immune surveillance and can be found in the lamina propria of the small intestine mucosa. MALT is not directly related to the secretory function of the intestinal glands but plays a crucial role in defending against pathogens.
Goblet cells, which are interspersed with the columnar epithelial cells lining the small intestine, are responsible for mucus secretion, but they are not the same as the intestinal glands; rather they are found within the glands among other cells.
The answer to the student's question 'What are the intestinal glands (crypts) of the small intestine?' is: C) tubular glands within the mucosa and submucosa that secrete intestinal juice.