Spit

Spit is the discharge of saliva from the mouth. The term also refers to the act of expelling saliva intentionally or unintentionally. In common usage, spit describes both the saliva itself and the act of spitting.

Saliva is produced by the salivary glands and serves several roles: lubricating and aiding swallowing; beginning digestion with enzymes; protecting teeth and mucosa; and contributing to taste. Human saliva production varies with hydration, arousal, and stimulation, typically about 0.5 to 1.5 liters per day.

Composition: saliva is mostly water (about 99%), with enzymes such as salivary amylase, mucins, electrolytes, and antimicrobial proteins including lysozyme and lactoferrin. Its pH ranges roughly from 6.2 to 7.6.

Spitting has varied culturally and historically. It has been a common practice in some cultures, associated with chewing tobacco or medicinal remedies; spittoons were widely used in the 19th and early 20th centuries. In many places, spitting in public is discouraged or prohibited due to cleanliness and disease concerns.

Health considerations: saliva can carry bacteria and viruses; spitting publicly can contribute to transmission of infections, especially in crowded settings. Good hygiene includes covering the mouth when coughing or sneezing and disposing of saliva in appropriate waste or a toilet.

Other uses of the term: “spittle” refers to frothy secretions produced by spittlebugs, known as cuckoo spit, unrelated to human saliva.