Eardrum the membrane as far as its center, drawing it toward the tympanic cavity. The lateral surface of the membrane is thus concave. The most depressed aspect of this concavity is termed the umbo (). Sensory innervation of the external surface of the tympanic membrane is supplied mainly by the auriculotemporal nerve, a branch of the mandibular nerve (cranial nerve V), with contributions from the auricular branch of the vagus nerve (cranial nerve X), the facial nerve (cranial nerve VII), and possibly the glossopharyngeal nerve (cranial nerve IX). The inner surface of the tympanic membrane is innervated by the glossopharyngeal nerve.
Common name nomenclature is a global system that attempts to denote particular organisms or taxa uniquely and , on the assumption that such organisms or taxa are well-defined and generally also have well-defined interrelationships; accordingly the ICZN has formal rules for biological nomenclature and convenes periodic international meetings to further that purpose. The form of scientific names for organisms that are called binomial nomenclature is superficially similar to the noun-adjective form of vernacular names or common names which were used by prehistoric cultures. A collective name such as "owl" was made more precise by the addition of an adjective such as "screech".