The immune system is a network of biological processes that protects an organism against disease. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinters, distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use molecules and cells to perform their functions. Humans have sophisticated defense mechanisms, including the ability to adapt to recognize pathogens more efficiently. Adaptive (or acquired) immunity creates an immunological memory leading to an enhanced response to subsequent encounters with that same pathogen. This process of acquired immunity is the basis of vaccination.

Read more: https://en.wikipedia.org/wiki/Immune_system

_______________________________ Today's selected anniversaries:

1460:

Wars of the Roses: At the Battle of Wakefield, Lancastrian forces destroyed the Yorkist army and killed Richard of York at Sandal Magna in West Yorkshire, England. https://en.wikipedia.org/wiki/Battle_of_Wakefield

1906:

The All-India Muslim League, a political party in British India that developed into the driving force behind the creation of Pakistan as a Muslim state on the Indian subcontinent, was founded in Dhaka. https://en.wikipedia.org/wiki/All-India_Muslim_League

1940:

The Arroyo Seco Parkway, one of the first freeways built in the U.S., connecting downtown Los Angeles with Pasadena, California, was officially dedicated. https://en.wikipedia.org/wiki/Arroyo_Seco_Parkway

2000:

A series of bombings occurred around Metro Manila in the Philippines, killing 22 people and injuring around 100 others. https://en.wikipedia.org/wiki/Rizal_Day_bombings

_____________________________ Wiktionary's word of the day:

hyperthymesia: (neuroscience) A rare condition in which an individual possesses a superior autobiographical memory and is able to recall the vast majority of personal events and experiences in life. https://en.wiktionary.org/wiki/hyperthymesia

___________________________ Wikiquote quote of the day:

Ye know who use the Crystal Ball ⁠(To peer by stealth on Doom), ⁠The Shade that, shaping first of all, ⁠⁠Prepares an empty room. ⁠⁠⁠Then doth It pass ⁠⁠⁠Like breath from glass, ⁠But, on the extorted vision bowed intent, ⁠No man considers why It came or went.   --Rudyard Kipling https://en.wikiquote.org/wiki/Rudyard_Kipling