Feces

Introduction

• Feces (or faeces) are the solid or semi-solid remains of food not digested in the small intestine.
• Broken down by bacteria in the large intestine.
• Contains small amounts of metabolic waste like bacterially-altered bilirubin and dead epithelial cells.
• Discharged through the anus or cloaca during defecation.

Uses and Applications

• Agriculture: Used as fertilizer or soil conditioner.
• Fuel: Dried feces can be burned as fuel.
• Construction: Used in certain construction materials.
• Medicine: Human feces used in fecal transplants.
• Other: Used in leather tanning and as fuel.

Physiological Aspects

• Excretion requires pressure generated by muscular contractions and gas buildup in the gut.
• Feces retain energy from undigested food, supporting ecosystems.
• Coprophagia: Some animals consume feces for nutrients.
• Raptors use fecal ultraviolet light reflection to locate prey.

Composition and Characteristics

• Smell due to skatole, thiols, amines, and carboxylic acids.
• Hydrogen sulfide contributes to odor.
• Bad odor hypothesized to deter human contact.

Ecology and Environmental Impact

• Serves as food for many organisms like bacteria, fungi, and insects.
• Important in seed dispersal and nutrient cycling.

Variations in Human Feces

• Diet and health affect appearance and frequency.
• Newborns' feces (meconium) differ in color and composition.

Historical and Cultural Aspects

• Coprolites: Fossilized feces used in paleontology.
• Paleofeces: Ancient feces analyzed for historical diets.

Etymology and Terminology

• "Feces" is derived from Latin "faex" meaning dregs.
• Synonyms include dung, scat, stool, etc.
• Various informal and vulgar terms exist for feces.

Cultural Perspectives

• Feelings of disgust are culturally derived.
• Associated with humor, especially in young children.

Synonyms and Terminology

• Varied terminology across different fields and contexts.

Miscellaneous Uses

• Innovative uses include paper production and luxury coffee making.
• Historical uses in leather tanning.