Immunological memory cells

Immunological memory is the capacity of the immune system to respond quickly to any invading pathogen or antigen. It is one of the characteristics bestowed on an organism by the existence of adaptive immunity which is a result of adaptive immune responses. This form of memory is characterized by a swarm of antigen-specific cells that are in charge of controlling viral reinfection. When activated in response to antigens or toxins, these cells go through a series of proliferative differentiation and expansion to become effector cells (Tappenden 27). Most of the effector cells die after the antigen has been dealt with, but come to persist to be available. The memory T-cell responses to the presence of an antigen or pathogen depend on the number of exposures of to the same. Therefore, it forms the basis of immunization since how it responds dictates the effectiveness of the immunization administered.

Structure and functionality of the Villus

A villus, villi in plural, is a structure found in the internal lining of the small intestine whose function is to absorb nutrients. Villi are finger-like projections that decorate the large folds located in the inner walls of the small intestines. Each of the villi has epithelial cells that have several appendages known as microvilli. During the process of digestion, absorption takes place in the small intestine with the help of the villi whereas the fat enters the lacteal while other nutrients are absorbed into the capillaries.

The main digestive enzymes produced in the small intestine are Erepsin, Maltase, Lactase, and Sucrase. Each of them is responsible for the digestion of a specific content of the food, and each works to enhance the absorption of all the nutrients. Erepsin is accountable for the peptones and polypeptides; maltase breaks down maltose, lactase digest lactose, and sucrose digest sucrose (Murphy and Casey 65). The small intestine is structured in a way that the surface area of absorption is increased by massive folds of the villi and microvilli.

Works Cited

Murphy, Kenneth, and Casey Weaver. Janeway's immunobiology. Garland Science, 2016.

Tappenden, Kelly A. "Intestinal adaptation following resection." Journal of Parenteral and Enteral Nutrition 38.1_suppl (2014): 23S-31S.