The nephridial organs are thought to be derived from similar organs in annelids, although reduced in number since the open circulatory system of arthropods lessens the demand on separate excretory organs. In humans, the premaxilla is referred to as the incisive bone and is the part of the maxilla which bears the incisor teeth, and encompasses the anterior nasal spine and alar region.In the nasal cavity, the premaxillary element projects higher than the maxillary element behind.The palatal portion of the premaxilla is a bony plate with a generally transverse orientation. Camatini, M. 1979. Primarily, then, it delivers information back from the following:. The Insects: An Outline of Entomology. The lacinia is often strongly sclerotized and toothed. Its posterior branch, called the condylar process, bears the mandibular condyle—an oval knob that articulates with the mandibular fossa of the temporal bone. In millipedes, the second maxillae have been lost, reducing the mouthparts to only the first maxillae which have fused together to form a gnathochilarium, acting as a lower lip to the buccal cavity and the mandibles which have been enlarged and specialized greatly, used for chewing food. Maxilla fractures are classified according to the Le Fort classification. Maxilla definition is - jaw. It is a branch of the trigeminal nerve (the fifth cranial nerve) which serves both a sensory (afferent) and motor (efferent) function. In most vertebrates, the foremost part of the upper jaw, to which the incisors are attached in mammals consists of a separate pair of bones, the premaxillae. It travels on the outer sidewall of the orbit to then subdivide into the zygomaticotemporal and zygomaticofacial branches, both of which run on the lower and lateral side of the orbit. The maxillary nerve is the second of three branches of the trigeminal nerve. They serve to transport food to the mandibles but also frequently help in the filtration process and additionally they may sometimes play a role in cleaning and grooming. These fuse with the maxilla proper to form the bone found in humans, and some other mammals. This has implications for dentists and doctors tasked with ensuring that the face or upper set of teeth are numbed prior to treatment.
In this article, we shall look at the anatomy of the maxillary nerve – its anatomical course, sensory and parasympathetic functions.

You can opt-out at any time. Each maxilla consists of two parts, the proximal cardo (plural cardines), and distal stipes (plural stipites). Blackwell Publishing, 10.1002/1097-4687(200007)245:1<19::AID-JMOR2>3.0.CO;2-H, https://en.wikipedia.org/w/index.php?title=Maxilla_(arthropod_mouthpart)&oldid=908562058, Creative Commons Attribution-ShareAlike License, This page was last edited on 30 July 2019, at 14:20. They have been described as the architectural key of the face because all bones of the face except the mandible touch them. Sensory information from these areas passes via axons to the trigeminal ganglion, located within an area called “Meckel’s cave,” a special pouch within the middle cranial fossa. These branches converge to form the sensory root of the trigeminal nerve and convey the sensory information to the brains at the level of the pons, a section associated with a range of bodily functions, such as sleep, breathing, swallowing, hearing, balance, among many others.
In bony fish, amphibians, and reptiles, both maxilla and premaxilla are relatively plate-like bones, forming only the sides of the upper jaw, and part of the face, with the premaxilla also forming the lower boundary of the nostrils. In many hexapods, the mouthparts have been modified for different functions and the maxillae and labium can change in structure greatly. The maxilla (plural: maxillae /mækˈsɪliː/)[2] in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. Anterior superior alveolar nerve: This branch splits off from the infraorbital nerve and travels along the sidewall of the maxillary sinus to convey sensory information from the mucous membranes. In the adult the vertical diameter is the greatest, owing to the development of the alveolar process and the increase in size of the sinus. The galea is a broad, scoop-like, lobe structure, which assists the maxillary palps in sampling items before ingestion. Pterygopalatine fossa: The middle course of the nerve, at the pterygopalatine fossa on each side of the skull, the maxillary nerve accesses the pterygopalatine ganglion and gives off a vast majority of its branches. Modified coxae at the base of the pedipalps in spiders are also called "maxillae",[1] although they are not homologous with mandibulate maxillae. The labium is immediately posterior to the first maxillae and is formed from the fusion of the second maxillae, although in lower orders including the Archaeognatha (bristletails) and Thysanura (silverfish) the two maxillae are not completely fused. Oxford University Press. The medial posterior superior nasal nerve moves towards the middle, across the nasal roof. The maxilla is ossified in membrane.

Birds do not have a maxilla in the strict sense; the corresponding part of their beaks (mainly consisting of the premaxilla) is called "upper mandible".