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Open Access Articles- Top Results for Head
International Journal of Innovative Research in Science, Engineering and TechnologyA Methodology for Cluster Head Selection to Improve Throughput and Channel Space Utilization in Power Heterogeneous MANET
International Journal of Innovative Research in Science, Engineering and TechnologyImproving Attack Detection and Reducing Communication Overhead For Mobile Adhoc Networks
International Journal of Innovative Research in Computer and Communication EngineeringReducing Routing Overhead In Manet Using Ncpr Protocol
International Journal of Innovative Research in Science, Engineering and TechnologyCluster Head Selection Based On Genetic Algorithm Using AHYMN Approaches in WSN
International Journal of Innovative Research in Science, Engineering and TechnologyEnergy Efficient Cluster Head Selection Scheme Based On FMPDM for MANETs
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A head is the cephalic part of an organism, which usually comprises the eyes, ears, nose and mouth, each of which aid in various sensory functions, such as sight, hearing, smell, and taste. Some very simple animals may not have a head, but many bilaterally symmetric forms do. Heads develop in animals by an evolutionary trend known as cephalization. In bilaterally symmetrical animals, nerve tissues concentrate at the anterior region, forming structures responsible for information processing. Through biological evolution, sense organs and feeding structures also concentrate into the interior region; these collectively form the head.
Cephalic is a term of, in, or relating to the cephalon, or head. The term is derived from the Old French word cephalique, from Latin cephalicus, and from Greek kephalikos (which comes from the word kephalē, meaning "head").
A typical insect head possesses a pair of antennae; eyes; mandibles, labrum, maxillae and labium (the latter four forming the cluster of "mouth parts"). Lying above the oesophagus is the brain or supraesophageal ganglion, divided into three pairs of ganglia: the protocerebrum, deutocerebrum and tritocerebrum from front to back.
Versus invertebrate chordates
Though invertebrate chordates such as the lancelet have heads, there has been a question of how the vertebrate head, characterized by a bony skull clearly separated from the main body, might have evolved from the head structures of these animals. In 2014, a transient larval tissue of the lancelet was found to be virtually indistinguishable from the neural crest-derived cartilage which forms the vertebrate skull, suggesting that persistence of this tissue and expansion into the entire head space could be a viable evolutionary route to formation of the vertebrate head.
Use in heraldry
Both human and animal heads frequently occur as immobile charges in heraldry. The blazon, or heraldic description, usually states whether an animal's head is couped (as if cut off cleanly at the neck), erased (as if forcibly ripped from the body), or cabossed (turned affronté without any of the neck showing). Human heads are often described in much greater detail, though some of these are identified by name with little or no further description.
- View of a Skull III.jpg
Mid-sagittal section of a human skull, by Leonardo da Vinci, c. 1489
- Bartholin head transect.jpg
Transection of a human head, by Thomas Bartholin, 1673
- Head nerves.gif
Nerves of the human head, from Gray's Anatomy, 1858
- Zürcher Stadtheilige.jpg
Patron saints of Zürich, fresco, c. 1400-1425
- POL powiat kaliski COA.svg
Heraldic depiction of a bison head cabossed
- Cephalic disorder
- Cephalic flexure
- Cephalic index
- Cephalic phase
- Cephalic presentation
- Cephalic vein
- Oxford American Dictionary. Oxford University Press.
- Jandzik, D.; Garnett, A. T.; Square, T. A.; Cattell, M. V.; Yu, J. K.; Medeiros, D. M. (2014). "Evolution of the new vertebrate head by co-option of an ancient chordate skeletal tissue". Nature. doi:10.1038/nature14000. For laysummary see: "Evolution: How vertebrates got a head". Research. Nature (paper) 516 (7530): 171. 11 December 2014.
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