a product formed by the body to perform a specific function, like digestion (saliva) or excretion (mucus and urine)

Mucus or phlegm from the respiratory passages.

Fluid, often called mucous produced by the mucous glands. Coughing up mucous from the lungs usually means a problem in the airways, but not always an infection. The mucous may be clear, yellow, or green. Asthma that is not well-controlled may cause coloured mucous to be coughed up.

Mucous and body fluids.

solid, liquid or gasses produced by cellular or glandular activity

substances produced by and released from cells (e.g. proteins)