2" tall tap Handle Limited Edition Ferrule.Will work on all american taps. Keg beer is a term for beer which is served from a pressurized keg. While often considered synonymous to draught beer, keg beer refers specifically to beer served under pressure, while draught beer may refer to any beer served from a larger container, including both keg beer and cask ale. Keg beer is often filtered and/or pasteurized, both of which are processes that render the yeast inactive, increasing the shelf life of the product at the expense of flavor. In brewing parlance, a keg is different from a cask. A cask has a tap hole near the edge of the top, and a spile hole on the side used for conditioning the unfiltered and unpasteurised beer. A keg has a single opening in the centre of the top to which a flow pipe is attached. Kegs are artificially pressurised after fermentation with carbon dioxide or a mixture of carbon dioxide and nitrogen gas. Keg has become a term of contempt used by some since the 1960s as pasteurised draught beers were replacing traditional cask beers. The quality of the kegging process was not as good then as it is today, and sometimes the keg beers are referred to as Plastic Beer. Some people believed that chemicals (adjuncts) were used to create a foam head. These perceptions still dog Keg beer to this day. Despite this consumer concern, keg beer was replacing traditional cask ale in all parts of the UK, primarily because it requires less care to handle. Since the mid-1970s, the Campaign for Real Ale (CAMRA) has been conducting a successful consumer campaign which focused attention on those consumers who preferred traditional cask beer. As well as this CAMRA has lobbied the British Parliament successfully to ensure support for cask ale. New, small microbreweries have sprung up to serve those consumers who prefer traditional cask beer. Today most pubs in the UK will serve both keg and cask beer. The skull is a bony structure found in many animals which serves as the general framework for the head. The skull supports the structures of the face and protects the head against injury. The skull can be subdivided into two parts: the cranium and the mandible. A skull that is missing a mandible is only a cranium; this is the source of a very commonly made error in terminology. Those animals having skulls are called craniates. Protection of the brain is only one part of the function of a bony skull. For example, a fixed distance between the eyes is essential for stereoscopic vision, and a fixed position for the ears helps the brain to 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. Contents
1 Human skulls 2 Possible types of skull fractures 2.1 Mid-facial Skeletal fracture 2.2 Le Fort I Fractures 2.3 Le Fort II Fractures 2.4 Le Fort III Fractures 3 Animal skulls 3.1 Temporal Fenestra 3.1.1 Classification 4 See also 5 References 6 External links [edit] Human skulls Main article: Human skull Human skull (front) Human skull (side) In humans, the adult skull is normally made up of 22 bones. Except for the mandible, all of the bones of the skull are joined together by sutures, rigid articulations permitting very little movement. Eight bones form the neurocranium (braincase), a protective vault surrounding the brain. Seventeen bones form the skunt, the bones supporting the face. Encased within the temporal bones are the six ear ossicles of the middle ears, though these are not part of the skull. The hyoid bone, supporting the tongue, is usually not considered as part of the skull either, as it does not articulate with any other bones, though it may be considered a part of the skunt. The skull contains the sinus cavities, which are air-filled cavities lined with respiratory epithelium, which also lines the large airways. The exact functions of the sinuses are unclear; they may contribute to lessening the weight of the skull with a minimal reduction in strength,or they may be important in improving the resonance of the voice. In some animals, such as the elephant, the sinuses are extensive. The elephant skull needs to be very large, to form an attachment for muscles of the neck and trunk, but is also unexpectedly light; the comparatively small brain-case is surrounded by large sinuses which reduce the weight. The meninges are the three layers, or membranes, which surround the structures of the nervous system. They are known as the dura mater, the arachnoid mater and the pia mater. Other than being classified together, they have little in common with each other. In humans, the anatomical position for the skull is the Frankfurt plane, where the lower margins of the orbits and the upper borders of the ear canals are all in a horizontal plane. This is the position where the subject is standing and looking directly forward. For comparison, the skulls of other species, notably primates and hominids, may sometimes be studied in the Frankfurt plane. However, this does not always equate to a natural posture in life. [edit] Possible types of skull fractures The protection of the brain and other vascular and respitory structures provided by the skull, can be compromised if the skull is fractured. Various types of fractures are described below. [edit] Mid-facial Skeletal fracture The mid facial skeleton is made up of a considerable number of bones which are rarely, if ever, fractured in isolation The structure is such that it is able to withstand considerable force from below, but the bones are easily fractured by relatively trivial forces applied from other directions Analogous to a ‘matchbox’ sitting below and in front of a hard shell containing the brain and differs quite markedly from the rigid projection of the mandible below [edit] Le Fort I Fractures Low-level / Guerin type fractures Horizontal fracture of the maxilla immediately above the teeth and palate Piriform fossa across maxilla to pterygoid fissure May occur as a single entity or in association with le fort II and III fractures Sometimes present in association with a downwardly displaced fracture of the zygomatic complex [edit] Le Fort II Fractures Pyramidal or suprazygomatic fractures Fracture extends from dorsum of nose, across medial walls of orbit across the maxilla below the zygomatic bone to the pterygomaxillary fissure [edit] Le Fort III Fractures High level or suprazygomatic fractures The facial bones, including the zygomas are detached from the anterior cranial base Fracture line extends from the dorsum of the nose and cribiform plate along the medial and up the lateral wall of the orbit to the ZF suture [edit] Animal skulls [edit] Temporal Fenestra This Tyrannosaurus skull shows it was a diapsid The temporal fenestra are anatomical features of the amniote skull, 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 is 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 the more advanced sauropsids and synapsids did. As time progressed, sauropsids' 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.
