The body is occupied by myriad ducts, vessels, canals and hollow organs. These structures are alive: they alter their shape, either actively or by imposed pressure, they grow, divide and change size, strength, functional properties. The substances transported range from air to watery fluids such as tears to dense fluids such as blood or semen to hard materials such as solid ingesta. The motility in this variety of tubular structures is due to smooth muscles, vast assemblies of muscle cells (each a microscopic motor, 50-500 m long and 1-4 m across) embedded in a matrix of rigid or elastic fibres of collagen and elastin. The unitary elements of cells and matrix are very similar but their assembly into different architectures produces all the variety of structure and of functional performances.

We use transmission electron microscopy, immunofluorescence, confocal and scanning electron microscopy, and morphometric techniques, to reveal the 3-dimensional arrangement of the various organ walls and to catch the stages of their movement and change in shape.

The control of smooth muscle is multiple: endogenous to the muscle cells (myogenic), in response to stretch or compression, by hormones, by signals from adjacent coupled muscle cells, by physical stimuli such as light and heat, by chemicals released from nerve fibres.
The assembly and the maturation of the smooth musculature occur from early embryonic development, and they take place, together with its growth, at the same time as an organ is already performing their physiologic function of storage and transport, and they are both pre-programmed and adaptive.
In adult organisms we study the dynamic properties of the tubular organs which are at work for example in peristaltic contractions of the gut, in the control of air flow, in the reaction of blood vessels at every systolic pulse, in the storage and then voiding of urine.
Beside these transient and reversible changes in shape, there are also changes which are long-term, directional, partly irreversible, because smooth muscles are capable of further growth (or atrophy) and adjustments, at the cell, the tissue and the organ levels in response to functional demands. For example, when the intestine is partially obstructed by an ingrowing tumour or a constriction, the aboral part of the organ hypertrophies and the hypertrophic muscle becomes capable of overcoming the obstruction. Adaptive response of the bladder in prostatism maintains urinary flow, and loss of autonomic neurons in neuropathy or ageing, causes branching in the remaining neurons to make good the losses.
The adaptive changes we investigate involve the smooth musculature, its nerves and its vessels, and they reverberate in the related autonomic and sensory ganglia and in the pathways of the spinal reflexes. Our ultrastructural and histochemical studies reveal the widespread adaptation of mature tissues and organs to the variability and the mishaps of life.