This thesis studies verbal locutions in Spanish with a high degree of idiomaticity and frequency of use. The main objective of this research is to investigate to what extent cognitive processes triggered by metaphors and metonymies are responsible for the meaning of these locutions. For this purpose, a set of verbal locutions in Spanish language is analyzed, such as meter algo en la cabeza (to put something in the head), cerrar la boca (to close the mouth) and abrir mano (to open the hand), that involve a part of the human body. The body parts chosen for the set of locutions to be analyzed are cabeza (head), boca (mouth) and mano (hand). The main source of data collection is the Diccionario de la Lengua Española. The work is carried out within the theoretical perspective of Cognitive Linguistics and conceives metaphor as a conceptual mapping between two cognitive domains with analogous properties; and metonymy, as a process whereby a conceptual entity provides access to another conceptual entity within the same cognitive domain. In the analysis, the structure of the locutions is described, examples of the variety of expressions are given, and the role of the mentioned mechanisms of figuration in the constitution of the meaning of the selected verbal locutions is analyzed. The results of this work constitute evidence for the relevance of metaphor and metonymy in the constitution of the meaning of verbal locutions.