Final answer:
Mucosa-associated lymphoid tissue (MALT) is the answer to the question.
Step-by-step explanation:
Mucosa-associated lymphoid tissue (MALT) consists of an aggregate of lymphoid follicles directly associated with the mucous membrane epithelia. These tissues are not surrounded by a capsule and are distributed in the connective tissue of mucosa. Examples of MALT include tonsils, Peyer's patches in the small intestine, and bronchus-associated lymphoid tissue. These tissues play important roles in immune responses against ingested or inhaled substances.
Tonsils, for example, are clusters of lymphoid tissue located in the mucosa of the oral and nasal cavities. Peyer's patches are found in the small intestine and serve as sites for immune surveillance in the digestive system. Bronchus-associated lymphoid tissue (BALT) is present in the respiratory system, particularly in the bronchi, and contributes to local immune responses against inhaled pathogens.
The function of MALT is to protect mucous membrane surfaces from infections by initiating immune responses at sites where pathogens are likely to enter the body. This strategic distribution of lymphoid tissue helps safeguard the body's mucosal barriers.