Abstract
An anatomical description of the head skeleton of the carp (Cyprinus carpió) is given. The description is limited to what is relevant for the functioning of the respiratory pumps. An anatomical description of the head muscles of the carp is given. The result of the contraction of most of the head muscles through coupling of skeletal elements spreads farther over the respiratory system than only to the bones to which the muscles are attached directly. It is through this that in the first place all the muscles producing laterad movements, with the exception only of the dilator operculi, influence the volume of both the buccal and opercular cavities, and in the second place that contraction of the hypobranchial muscles not only results in vertical movements of the floor of all the respiratory cavities, but also in laterad movements of their side walls. The hyoid arch plays a central role in the coupling system because it interconnects almost all the other elements. The functional significance of the interaction through couplings is integration of the respiratory movements through which during low-intensity breathing whole muscles can cease to be active and during high-intensity respiration whole muscles can be recruited without seriously affecting the co-ordination of the movements and hence the hydrodynamic efficiency of the pumps.