Conteùdo de sensagent
1.the bony skeleton of the head of vertebrates
2.the part of the skull that encloses the brain
1.(MeSH)The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.
SkullSkull (?), n. [See School a multitude.] A school, company, or shoal. [Obs.]
A knavish skull of boys and girls did pelt at him. Warner.
These fishes enter in great flotes and skulls. Holland.
SkullSkull, n. [OE. skulle, sculle, scolle; akin to Scot. skull, skoll, a bowl, Sw. skalle skull, skal a shell, and E. scale; cf. G. hirnschale, Dan. hierneskal. Cf. Scale of a balance.]
1. (Anat.) The skeleton of the head of a vertebrate animal, including the brain case, or cranium, and the bones and cartilages of the face and mouth. See Illusts. of Carnivora, of Facial angles under Facial, and of Skeleton, in Appendix.
☞ In many fishes the skull is almost wholly cartilaginous but in the higher vertebrates it is more or less completely ossified, several bones are developed in the face, and the cranium is made up, wholly or partially, of bony plates arranged in three segments, the frontal, parietal, and occipital, and usually closely united in the adult.
2. The head or brain; the seat of intelligence; mind.
Skulls that can not teach, and will not learn. Cowper.
3. A covering for the head; a skullcap. [Obs. & R.]
Let me put on my skull first. Beau. & Fl.
4. A sort of oar. See Scull.
Skull and crossbones, a symbol of death. See Crossbones.
Absence of skull bone, congenital • Base of Skull • Basilar Skull Fracture • Bones of skull and face • Compound Depressed Skull Fracture • Compound Depressed Skull Fractures • Congenital anomaly of skull NOS • Crushing Skull Injury • Crushing injury of skull • Depressions in skull • Fracture of base of skull • Fracture of base of skull | closed • Fracture of base of skull | open • Fracture of skull and facial bones • Fracture of skull and facial bones, part unspecified • Fracture of skull and facial bones, part unspecified | closed • Fracture of skull and facial bones, part unspecified | open • Fracture of skull due to birth injury • Fracture of vault of skull • Fracture of vault of skull | closed • Fracture of vault of skull | open • Fractures of other skull and facial bones • Fractures of other skull and facial bones | closed • Fractures of other skull and facial bones | open • Hyperostosis of skull • Hyperostosis of skull | ankle and foot • Hyperostosis of skull | forearm • Hyperostosis of skull | hand • Hyperostosis of skull | lower leg • Hyperostosis of skull | multiple sites • Hyperostosis of skull | other • Hyperostosis of skull | pelvic region and thigh • Hyperostosis of skull | shoulder region • Hyperostosis of skull | site unspecified • Hyperostosis of skull | upper arm • Imperfect fusion of skull • Linear Skull Fracture • Neoplasms, Skull • Neoplasms, Skull Base • Non-Depressed Skull Fracture • Other birth injuries to skull • Paget's disease of skull • Paget's disease of skull | ankle and foot • Paget's disease of skull | forearm • Paget's disease of skull | hand • Paget's disease of skull | lower leg • Paget's disease of skull | multiple sites • Paget's disease of skull | other • Paget's disease of skull | pelvic region and thigh • Paget's disease of skull | shoulder region • Paget's disease of skull | site unspecified • Paget's disease of skull | upper arm • Sequelae of fracture of skull and facial bones • Skull Base • Skull Base Neoplasms • Skull Fracture, Basilar • Skull Fracture, Basilar, Childhood • Skull Fracture, Compound Depressed • Skull Fracture, Depressed • Skull Fracture, Frontobasilar • Skull Fracture, Linear • Skull Fracture, Non-Depressed • Skull Fracture, Transphenoid Basilar • Skull Fractures • Skull Fractures, Compound Depressed • Skull Neoplasms • Skull plate • membranous skull • skull and crossbones • skull defects associated with congenital anomalies of brain such as anencephaly • skull defects associated with congenital anomalies of brain such as encephalocele • skull defects associated with congenital anomalies of brain such as hydrocephalus • skull defects associated with congenital anomalies of brain such as microcephaly • skull practice • skull session
Atomic Skull • Back to Skull • Base of skull • Basilar skull fracture • Blazing Skull • Broken Hill Skull • Brown Heart Skull Sampler • Bulk and Skull • Calaveras Skull • Calvaria (skull) • Cap and Skull • Castle Skull • Chapter One (Viking Skull album) • Chapter Two (Viking Skull album) • Comminuted skull fracture • Country of My Skull • Crystal Skull (Stargate SG-1) • Crystal skull • Crystal skull (disambiguation) • Depressed skull fracture • Diastatic skull fracture • Egg-shell skull • Egg-shell skull doctrine • Egg-shell skull rule • Eggshell skull • Eggshell skull rule • Exiles (Red Skull allies) • Florisbad Skull • Foramen ovale (skull) • Foramina of the skull • Geronimo's skull • Green Skull • Heavy Deavy Skull Lover • Hofmeyr Skull • Human skull • Indiana Jones and the Crystal Skull • Indiana Jones and the Kingdom of the Crystal Skull (soundtrack) • It's a skull • Jake Ransom and the Skull King's Shadow • Jewel in the skull • Kabwe skull • Legend of the Crystal Skull • Linear skull fracture • List of Skull and Bones members • Live Skull • Old Skull • Old Skull (comics) • Penetrating skull fracture • Pink Heart Skull Sampler • Red Skull • Red Skull (Albert Malik) • Return to Spider-Skull Island • Riders of the Whistling Skull • SKULL (DC Comics) • Sam the Skull • Skull (comics) • Skull (disambiguation) • Skull (music) • Skull (song) • Skull (symbol) • Skull (symbolism) • Skull Bearers • Skull Bearers (Shannara) • Skull Cave • Skull Cave (Mackinac Island) • Skull Creek • Skull Creek Township, Butler County, Nebraska • Skull Disco • Skull Duggery • Skull EP • Skull Fang Kuhga Gaiden • Skull Gang • Skull Gang (album) • Skull Greymon • Skull Heads • Skull Island • Skull Island (Australia) • Skull Island (Washington) • Skull Island (disambiguation) • Skull Island Uplands • Skull Islet • Skull Man • Skull Mountain • Skull Murphy • Skull Nebula • Skull Rack • Skull Ring • Skull Rock • Skull Snaps • Skull Tower • Skull Valley Elementary School District • Skull Valley Indian Reservation • Skull Valley, Arizona • Skull and Bones • Skull and Bones (Millennium) • Skull and Bones Society • Skull and Dagger (honor society) • Skull and crossbones • Skull and crossbones (Spanish cemetery) • Skull and crossbones (fraternities and sports) • Skull and crossbones (military) • Skull and crossbones (poison) • Skull art • Skull base fracture • Skull bones • Skull crucible • Skull cup • Skull fracture • Skull gang entertainment • Skull roof • Skull symbolism • Skull the Slayer • Skull-A-Day • Skull-Face • Skull-Face and Others • Soft Skull Press • Something Is Squeezing My Skull • Starchild skull • Steinheim Skull • The 4 Brothers Meet Misery Skull • The Bees Made Honey in the Lion's Skull • The Gryphon's Skull • The House on Skull Mountain • The Jewel in the Skull • The Screaming Skull • The Secret of Skull Mountain • The Senior Skull Honor Society • The Skull • The Skull (album) • The Skull Beneath the Skin • The Skull Collectors • The Skull of Sobek • Thin skull rule • Viking Skull • White Skull • Wooden Octopus Skull Experimental Musick PFestival
Skull (n.) [MeSH]
viande de veau (fr)[Classe]
sheep; mouton; mutton[Classe]
chose réduite (fr)[ClasseParExt.]
squelette humain (fr)[Thème]
systèmes du corps humain (fr)[DomainDescrip.]
intérieur du corps humain (fr)[DomainDescrip.]
description de la tête (fr)[DomainDescrip.]
anatomie de l'oiseau (fr)[DomainDescrip.]
anatomie des insectes (fr)[DomainDescrip.]
extérieur du corps humain (fr)[DomainDescrip.]
anatomie des mammifères (fr)[DomainDescrip.]
élément du squelette humain (fr)[Classe]
tête humaine (fr)[DomainDescrip.]
élément du squelette humain (fr)[Classe]
relatif à (fr)[Classe...]
tête humaine (fr)[DomainDescrip.]
chose tangible servant de protection (fr)[ClasseParExt.]
Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to help the brain use auditory cues to judge direction and distance of sounds. In some animals, the skull also has a defensive function (e.g. horned ungulates); the frontal bone is where horns are mounted.
The skull is made of flat bones.
The skull of fishes is formed from a series of only loosely connected bones. lampreys and sharks only possess a cartilaginous endocranium, with both the upper and lower jaws being separate elements. Bony fishes have additional dermal bone, forming a more or less coherent skull roof in lungfish and holost fish. The lower jaw defines a chin.
The simpler structure is found in jawless fish, in which the cranium is represented by a trough-like basket of cartilaginous elements only partially enclosing the brain, and associated with the capsules for the inner ears and the single nostril. Distinctively, these fish have no jaws.
Cartilaginous fish, such as sharks, have also simple, and presumably primitive, skull structures. The cranium is a single structure forming a case around the brain, enclosing the lower surface and the sides, but always at least partially open at the top as a large fontanelle. The most anterior part of the cranium includes a forward plate of cartilage, the rostrum, and capsules to enclose the olfactory organs. Behind these are the orbits, and then an additional pair of capsules enclosing the structure of the inner ear. Finally, the skull tapers towards the rear, where the foramen magnum lies immediately above a single condyle, articulating with the first vertebra. There are, in addition, at various points throughout the cranium, smaller foramina for the cranial nerves. The jaws consist of separate hoops of cartilage, almost always distinct from the cranium proper.
In the ray-finned fishes, there has also been considerable modification from the primitive pattern. The roof of the skull is generally well formed, and although the exact relationship of its bones to those of tetrapods is unclear, they are usually given similar names for convenience. Other elements of the skull, however, may be reduced; there is little cheek region behind the enlarged orbits, and little, if any bone in between them. The upper jaw is often formed largely from the premaxilla, with the maxilla itself located further back, and an additional bone, the symplectic, linking the jaw to the rest of the cranium.
Although the skulls of fossil lobe-finned fish resemble those of the early tetrapods, the same cannot be said of those of the living lungfishes. The skull roof is not fully formed, and consists of multiple, somewhat irregularly shaped bones with no direct relationship to those of tetrapods. The upper jaw is formed from the pterygoids and vomers alone, all of which bear teeth. Much of the skull is formed from cartilage, and its overall structure is reduced.
The skulls of the earliest tetrapods closely resembled those of their ancestors amongst the lobe-finned fishes. The skull roof is formed of a series of plate-like bones, including the maxilla, frontals, parietals, and lacrimals, among others. It is overlaying the endocranium, corresponding to the cartilaginous skull in sharks and rays. The various separate bones that compose the temporal bone of humans are also part of the skull roof series. A further plate composed of four pairs of bones forms the roof of the mouth; these include the vomer and palatine bones. The base of the cranium is formed from a ring of bones surrounding the foramen magnum and a median bone lying further forward; these are homologous with the occipital bone and parts of the sphenoid in mammals. Finally, the lower jaw is composed of multiple bones, only the most anterior of which (the dentary) is homologous with the mammalian mandible.
In living tetrapods, a great many of the original bones have either disappeared, or fused into one another in various arrangements.
In mammals and birds, in particular, modifications of the skull occurred to allow for the expansion of the brain. The fusion between the various bones is especially notable in birds, in which the individual structures may be difficult to identify.
The fenestrae (from Latin, meaning windows) are openings in the skull.
The temporal fenestrae are anatomical features of the skulls of several types of amniotes, characterised by bilaterally symmetrical holes (fenestrae) in the temporal bone. Depending on the lineage of a given animal, two, one, or no pairs of temporal fenestrae may be present, above or below the postorbital and squamosal bones. The upper temporal fenestrae are also known as the supratemporal fenestrae, and the lower temporal fenestrae are also known as the infratemporal fenestrae. The presence and morphology of the temporal fenestra are critical for taxonomic classification of the synapsids, of which mammals are part.
Physiological speculation associates it with a rise in metabolic rates and an increase in jaw musculature. The earlier amniotes of the Carboniferous did not have temporal fenestrae but two more advanced lines did: the Synapsids (mammal-like reptiles) and the Diapsids (most reptiles and later birds). As time progressed, diapsids' and synapsids' temporal fenestrae became more modified and larger to make stronger bites and more jaw muscles. Dinosaurs, which are sauropsids, have large advanced openings and their descendants, the birds, have temporal fenestrae which have been modified. Mammals, which are synapsids, possess no fenestral openings in the skull, as the trait has been modified. They do, though, still have the temporal orbit (which resembles an opening) and the temporal muscles. It is a hole in the head and is situated to the rear of the orbit behind the eye.
There are four types of amniote skull, classified by the number and location of their fenestra. These are:
Evolutionarily, they are related as follows:
In humans, as in other mammals, the aforementioned division of the skull into the cranium and mandible is not usually followed. Instead, for the purposes of describing their anatomy and enumerating their bones, mammalian and human skulls are divided differently: They are deemed to consist of two categorical parts, the neurocranium and the viscerocranium. The neurocranium (or braincase) is a protective vault surrounding the brain. The viscerocranium (also splanchnocranium or facial skeleton) is formed by the bones supporting the face. Both parts have different embryological origins.
The jugal is a skull bone found in most reptiles, amphibians, and birds. In mammals, the jugal is often called the malar or zygomatic.
The prefrontal bone is a bone separating the lacrimal and frontal bones in many tetrapod skulls.
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