Functional element, in particular fluid pump, having a housing and a conveying element

A fluid pump having a housing delimiting a fluid chamber and having a conveying element for the fluid disposed in the fluid chamber, both the housing and the conveying element, with respect to the shape and/or size thereof, being able to be changed between at least a first, expanded state and a second, compressed state,

• the housing having at least one stabilisation chamber, which can be supplied with a fluid pressure and is different from the fluid chamber, between an inner side and an outer side, in particular an inner wall and an outer wall of the housing, the first state of the housing being assigned to a first fluid pressure in the stabilisation chamber and the second state of the housing being assigned to a second fluid pressure and the inner and/or outer wall of the housing being elastic and contracting elastically into the second state during the transition from the first into the second state.