Schematic drawings of oscillating pumps in both engineering and biology. A Piston pump in engineering can, for instance, be used to pump water. B Salivary pump in Hemiptera. a: piston retracted; b: piston position with relaxed muscle. Cu cupula, Dia diaphragma, P pistill, PG efferent salivary duct, SpG afferent salivary duct, V1 V2 valves (from Weber 1930). C Frontal section of the human heart (from OpenStax College 2013, CC-BY-3.0). For further explanations, see text.

  Part of: Drack M, Betz O (2022) A technomorphic conceptualisation of biological ‘constructions’ and their evolution. Vertebrate Zoology 72: 839-855.