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Lesser Trochanter
The lesser trochanter is a conical posteromedial bony projection of the femoral shaft. it serves as the principal insertion site of the iliopsoas muscle. Structure The lesser trochanter is a conical posteromedial projection of the shaft of the femur, projecting from the posteroinferior aspect of its junction with the femoral neck. The summit and anterior surface of the lesser trochanter are rough, whereas its posterior surface is smooth. From its apex three well-marked borders extend: * two of these are above ** a medial continuous with the lower border of the femur neck ** a lateral with the intertrochanteric crest * the inferior border is continuous with the middle division of the linea aspera Attachments The summit of the lesser trochanter gives insertion to the tendon of the psoas major muscle and the iliacus muscle; the lesser trochanter represents the principal attachment of the iliopsoas. Anatomical relations The intertrochanteric crest (which demarcates the junctio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia (shinbone) and patella (kneecap), forming the knee joint. By most measures the two (left and right) femurs are the strongest bones of the body, and in humans, the largest and thickest. Structure The femur is the only bone in the upper leg. The two femurs converge medially toward the knees, where they articulate with the proximal ends of the tibiae. The angle of convergence of the femora is a major factor in determining the femoral-tibial angle. Human females have thicker pelvic bones, causing their femora to converge more than in males. In the condition ''genu valgum'' (knock knee) the femurs converge so much that the knees touch one another. The opposite extreme is ''genu varum'' (bow-leggedness). In the general populatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prozostrodontia
Prozostrodontia is a clade of cynodonts including mammaliaforms and their closest relatives such as Tritheledontidae and Tritylodontidae. It was erected as a node-based taxon by Liu and Olsen (2010) and defined as the least inclusive clade containing ''Prozostrodon brasiliensis'', '' Tritylodon langaevus'', '' Pachygenelus monus'', and ''Mus musculus'' (the house mouse). Prozostrodontia is diagnosed by several characters, including: * Reduced prefrontal and postorbital bones, with a reduction or disappearance of a strut of bone called the postorbital bar separating the eye socket from the temporal region * Unconnected dentary bones in the lower jaw * The presence of a small hole in the skull called the sphenopalatine foramen * A sagittal crest extending along the top of the skull and connecting with a lambdoidal crest at the back of the skull * Neural spines of the dorsal vertebrae angled backward * A convex-shaped iliac crest and a reduced posterior iliac spine on the hip * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Third Trochanter
In human anatomy, the third trochanter is a bony projection occasionally present on the proximal femur near the superior border of the gluteal tuberosity. When present, it is oblong, rounded, or conical in shape and sometimes continuous with the gluteal ridge. It generally occurs bilaterally without significant side to side dimorphism. A structure of minor importance in humans, the incidence of the third trochanter varies from 17 to 72% between ethnic groups and it is frequently reported as more common in females than in males. Structures analogous to the third trochanter are present in other mammals, including some primates. It is called the third trochanter in reference to the greater and lesser trochanters that are always present on the femur. Function Its function is to provide an attachment for the ascending tendon of the gluteus maximus muscle. It may function as (1) a reinforcement mechanism for the proximal femoral diaphysis in response to increased ground reaction f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Trochanter
The greater trochanter of the femur is a large, irregular, quadrilateral eminence and a part of the skeletal system. It is directed lateral and medially and slightly posterior. In the adult it is about 2–4 cm lower than the femoral head.Standring, Susan, editor. ''Gray’s Anatomy: The Anatomical Basis of Clinical Practice''. Forty-First edition, Elsevier Limited, 2016, p. 1327. Because the pelvic outlet in the female is larger than in the male, there is a greater distance between the greater trochanters in the female. It has two surfaces and four borders. It is a traction epiphysis. Surfaces The ''lateral surface'', quadrilateral in form, is broad, rough, convex, and marked by a diagonal impression, which extends from the postero-superior to the antero-inferior angle, and serves for the insertion of the tendon of the gluteus medius. Above the impression is a triangular surface, sometimes rough for part of the tendon of the same muscle, sometimes smooth for the interposi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mus Musculus
Mus or MUS may refer to: Abbreviations * MUS, the NATO country code for Mauritius * MUS, the IATA airport code for Minami Torishima Airport * MUS, abbreviation for the Centre for Modern Urban Studies on Campus The Hague, Leiden University, Netherlands * MUS, abbreviation for Medically unexplained physical symptoms * MUS, abbreviation for the Memphis University School * MUS, abbreviation for the Movimiento Unión Soberanista * MUS, abbreviation for Multiple-use water supply system, a low-cost, equitable water supply systems * Mus, abbreviation for Musca, a southern constellation * mus, ISO-639 code for the Muscogee language * Mus., abbreviation used in music degrees such as B.Mus. and M.Mus. * MUs, or million units of energy, used in India for a gigawatt hour People * Anders Mus (fl. 1501–1535), Danish civil servant in Norway * Conny Mus (1950–2010), Dutch journalist, best known as a correspondent for ''RTL Nieuws'' in Israel and the Middle East * Gus Mus (born 1944), I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachygenelus Monus
''Pachygenelus'' is an extinct genus of tritheledontid cynodonts. Fossils have been found from the Karoo basin in South Africa and date back to the Early Jurassic. ''Pachygenelus'' had both an articular- quadrate and dentary-squamosal jaw joint characteristic of ictidosaurs. Only mammals possess the dentary-squamosal articulation, while all other tetrapods possess the typical arcticular-quadrate articulation. Thus the jaw of ''Pachygenelus'' can be seen as transitional between non-mammalian synapsids and true mammals. Another feature of ''Pachygenelus'' that is shared with mammals is plesiomorphic prismatic enamel, or enamel arranged into strengthened prisms. The upper and lower tooth rows occluded with one another, although not as close as what is seen in true mammals. Wear facets are present on the lingual sides of the upper and external faces of the lower postcanines, and are seen as evidence for the occlusion. Despite all of the derived adaptation seen in its teeth, the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tritylodon Langaevus
''Tritylodon'' (Greek for 3 cusped tooth) is an extinct genus of tritylodonts, one of the most advanced group of cynodont therapsids. They lived in the Early Jurassic and possibly Late Triassic periods along with dinosaurs. They also shared many characteristics with mammals, and were once considered mammals because of overall skeleton construction. That was changed due to them retaining the vestigial reptilian jawbones and a different skull structure. Tritylodons are now regarded as non-mammalian synapsids. Characteristics If a living ''Tritylodon'' were to be seen today, it would look a lot like a large rodent. They were about long but there is no certainty about the exact weight. Their method of chewing food, a grinding motion with the bottom teeth sliding against the top teeth, resembled that of rodents as well. The bottom teeth were much like a set of cusps and the top teeth were a set of matching grooves that matched perfectly allowing this motion. There were large inciso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prozostrodon Brasiliensis
''Prozostrodon'' is an extinct genus of advanced cynodonts that was closely related to the ancestors of mammals. The remains were found in Brazil and are dated middle to late Triassic. It was originally described as a species of ''Thrinaxodon'' and was probably fairly similar to that genus in overall build. The holotype has a skull length of 6.7 cm, indicating the whole animal may have been the size of a cat, though there is some doubt as to whether the find represents an adult individual. The teeth were typical of advanced cynodonts, and the animal was probably a small carnivore hunting reptiles and other small prey. Later analysis indicated ''Prozostrodon'' was more closely related to the mammals than to the ''Thrinaxodon'' species, and it was given its own genus. Cladistic analysis indicates its closest relatives gave rise to the first mammaliaforms and therefore to the crown group mammals. The holotype of ''Prozostrodon'' was found in the Geopark of Paleorrota, Santa Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Node-based Taxon
Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a '' type'', which can be a specimen or a taxon of lower rank, and a description in words. Phylogenetic nomenclature is currently regulated by the '' International Code of Phylogenetic Nomenclature'' (''PhyloCode''). Definitions Phylogenetic nomenclature ties names to clades, groups consisting of an ancestor and all its descendants. These groups can equivalently be called monophyletic. There are slightly different ways of specifying the ancestor, which are discussed below. Once the ancestor is specified, the meaning of the name is fixed: the ancestor and all organisms which are its descendants are included in the named taxon. Listing all these organisms (i.e. providing a full circumscription) requires the full phylogenetic tree to be known. In practice, ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammaliform
Mammaliaformes ("mammalian forms") is a clade that contains the crown group mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts. It is defined as the clade originating from the most recent common ancestor of Morganucodonta and the crown group mammals; the latter is the clade originating with the most recent common ancestor of extant Monotremata, Marsupialia, and Placentalia. Besides Morganucodonta and the crown group mammals, Mammaliaformes includes Docodonta and '' Hadrocodium'' as well as the Triassic '' Tikitherium'', the earliest known member of the group. Mammaliaformes is a term of phylogenetic nomenclature. In contrast, the assignment of organisms to Mammalia has traditionally been founded on traits and, on this basis, Mammalia is slightly more inclusive than Mammaliaformes. In particular, trait-based taxonomy generally includes ''Adelobasileus'' and ''Sinoconodon'' in Mammalia, though they fall outside the Mam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynodont
The cynodonts () (clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variety of lifestyles, including carnivory and herbivory. Mammals are cynodonts, as are their extinct ancestors and close relatives, having evolved from advanced probainognathian cynodonts during the Late Triassic. All other cynodont lines went extinct, with the last known non-mammalian cynodont group, the Tritylodontidae, having its youngest records in the Early Cretaceous. Description Early cynodonts have many of the skeletal characteristics of mammals. The teeth were fully differentiated and the braincase bulged at the back of the head. Outside of some crown-group mammals (notably the therians), all cynodonts probably laid eggs. The temporal fenestrae were much larger than those of their ancestors, and the widening of the zygomatic arch in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
