Cephalization


Also found in: Dictionary, Medical, Wikipedia.

cephalization

[‚sef·ə·lə′zā·shən]
(zoology)
Anterior specialization resulting in the concentration of sensory and neural organs in the head.

Cephalization

 

the intensified development of the cephalic portion of the body in bilaterally symmetric animals during the process of evolution. The head end of the body, which includes the oral orifice, is first to experience new objects in the environment. As a result, the sense organs (vision, olfaction, touch, and hearing, the latter being developed only in vertebrates) and the sections of the nervous system that regulate the sense organs and make up the brain are concentrated in the head end of the body. In vertebrates a skull has developed to protect the aforementioned organs. In invertebrates this protective function is performed by a hard external cover. In cephalopods the brain is protected by a cartilage capsule.

References in periodicals archive ?
For example the "hunter hypothesis" considered the upright posture and cephalization as integral parts of the evolutionary process linked to making tools--manipulation required hands that are freed from locomotion and a developed brain to direct the process, in addition to the tools used in hunting big game.
And good fits becoming evident as we proceed, even in unlikely crossings (such as, perhaps, cephalization with cubism), are consiliences.
The cephalization of economic life brought about by the industrial revolution was not sui generis.
In such cases we say the organism has undergone cephalization and
Specifically, the adult nervous systems of nudibranchs manifest a high degree of cephalization with fusion of the cerebral and pleural ganglia, close proximity of the pedal ganglia with the cerebropleural ganglia, and an absence of major posterior ganglia.