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Crest (anatomy)
A crest is any of various anatomical features appearing as a raised point or ridge, most prominently those on the head or back of an animal. *A part of a bone: **Sagittal crest **Cnemial crest **Iliac crest **Frontal crest ** Infratemporal crest ** Anterior lacrimal crest ** Posterior lacrimal crest **Buccinator crest *A feature on various animals: **Crest (feathers) ** Display feature or thermoregulatory feature in various reptiles ** Sail (anatomy), also known as ''crest'' in some animals **The point of a horse's neck where the mane grows from *Neural crest Neural crest cells are a temporary group of cells unique to vertebrates that arise from the embryonic ectoderm germ layer, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, per ..., a temporary group of cells unique to vertebrates that arise from the embryonic ectoderm cell layer {{SIA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, 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, regardless of size. Heads develop in animals by an evolutionary trend known as cephalization. In bilaterally symmetrical animals, nervous tissue concentrate at the anterior region, forming structures responsible for information processing. Through biological evolution, sense organs and feeding structures also concentrate into the anterior region; these collectively form the head. Human head The human head is an anatomical unit that consists of the Human skull, skull, hyoid bone and cervical vertebrae. The term "skull" collectively denotes the mandible (lower jaw bone) and the cranium (upper portion of the skull that houses the brain). Sculptures of human heads are general ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagittal Crest
A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are exceptionally strong jaw muscles. The sagittal crest serves primarily for attachment of the temporalis muscle, which is one of the main chewing muscles. Development of the sagittal crest is thought to be connected to the development of this muscle. A sagittal crest usually develops during the juvenile stage of an animal in conjunction with the growth of the temporalis muscle, as a result of convergence and gradual heightening of the temporal lines. Function A sagittal crest tends to be present on the skulls of adult animals that rely on powerful biting and clenching of their teeth, usually as a part of their hunting strategy. Skulls of some dinosaur species, including tyrannosaurs, possessed well developed sagittal crests. Among mammals, dogs, cats, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnemial Crest
The cnemial crest is a crestlike prominence located at the front side of the head of the tibiotarsus or tibia in the legs of many mammals and reptiles (including birds and other dinosaurs). The main extensor muscle of the thigh In human anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the lower limb. The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of bone ... is attached to this ridge. References Bird anatomy {{ornithology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iliac Crest
The crest of the ilium (or iliac crest) is the superior border of the wing of ilium and the superiolateral margin of the greater pelvis. Structure The iliac crest stretches posteriorly from the anterior superior iliac spine (ASIS) to the posterior superior iliac spine (PSIS). Behind the ASIS, it divides into an outer and inner lip separated by the intermediate zone. The outer lip bulges laterally into the iliac tubercle. Platzer (2004), p 186 Palpable in its entire length, the crest is convex superiorly but is sinuously curved, being concave inward in front, concave outward behind. Palastanga (2006), p 243 It is thinner at the center than at the extremities. Development The iliac crest is derived from endochondral bone. Function To the external lip are attached the ''Tensor fasciae latae'', '' Obliquus externus abdominis'', and '' Latissimus dorsi'', and along its whole length the '' fascia lata''; to the intermediate line, the '' Obliquus internus abdominis''. To the inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontal Crest
The frontal crest is a ridge on the internal surface of the squamous part of the frontal bone formed by the inferior convergence of the two edges of the sagittal sulcus. The frontal crest gives attachment to the falx cerebri The falx cerebri (also known as the cerebral falx) is a large, crescent-shaped fold of dura mater that descends vertically into the longitudinal fissure between the cerebral hemispheres of the human brain,Saladin K. "Anatomy & Physiology: The Uni .... References Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infratemporal Crest
The lateral surface of the greater wing of the sphenoid is convex, and divided by a transverse ridge, the infratemporal crest, into two portions. The superior or temporal portion, convex from above downward, concave from before backward, forms a part of the temporal fossa, and gives attachment to the Temporalis In anatomy, the temporalis muscle, also known as the temporal muscle, is one of the muscles of mastication (chewing). It is a broad, fan-shaped convergent muscle on each side of the head that fills the temporal fossa, superior to the zygomatic a ...; the inferior or infratemporal, smaller in size and concave, enters into the formation of the infratemporal fossa, and, together with the infratemporal crest, affords attachment to the Pterygoideus externus. Additional images File:Gray189.png, Left infratemporal fossa. References External links * Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Lacrimal Crest
The anterior lacrimal crest is a bony projection on the frontal process of the maxilla. It creates the lateral margin of the lacrimal sac fossa and is continuous with the orbital margin. The medial palpebral ligament is attached to anterior lacrimal crest. It is an important structure to avoid damaging during rhinoplasty. Structure The anterior lacrimal crest is a bony projection on the frontal process of the maxilla in the skull. It reaches the junction between the maxilla and the lacrimal bone. At its junction with the orbital surface is a small tubercle, the lacrimal tubercle, which serves as a guide to the position of the lacrimal sac. The anterior lacrimal crest is much thicker and stronger than the posterior lacrimal crest. It is one of the thickest parts of the orbit. It is nearly always quite prominent, whilst the posterior lacrimal crest may be less prominent in some people. Relations The lacrimal sac is directly behind the anterior lacrimal crest, which prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Lacrimal Crest
The posterior lacrimal crest is a vertical bony ridge on the orbital surface of the lacrimal bone. It divides the bone into two parts. It gives origin to the lacrimal part of the orbicularis oculi muscle. Structure The posterior lacrimal crest is a vertical bony ridge on the orbital (lateral) surface of the lacrimal bone. It divides the lacrimal bone into two parts. It is quite thin and fragile in most people. The lacrimal groove is in front of this crest. The inner margin of it unites with the frontal process of the maxilla to complete the fossa for the lacrimal sac. The portion of the lacrimal bone behind the posterior lacrimal crest is smooth, and forms part of the medial wall of the orbit. The lacrimal crest ends below in the lacrimal hamulus (a small hook-like projection), which articulates with the lacrimal tubercle of the maxilla. Relations The posterior lacrimal crest is just behind the lacrimal sac, and its upper part lodges the lacrimal sac. The lower part lodges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buccinator Crest
The buccinator crest (Latin ''crista buccinatoria'') is a bony crest of the human mandible, that passes from the base of the coronoid process to the area of the third molar.https://medical-dictionary.thefreedictionary.com/buccinator+crest The free dictionary's medical dictionary defenition of buccinator crest The alveolar border of the buccinator muscle The buccinator () is a thin quadrilateral muscle occupying the interval between the maxilla and the mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity.Illustrated Anatomy of the Head ... attaches upon it. References Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crest (feathers)
The crest is a prominent feature exhibited by several bird and other dinosaur species on their heads. It is distinct from features such as casques and cockscombs - sometimes erroneously referred to as "crests", which are bony and fleshy structures respectively. The crest is made up of semiplume feathers: a long rachis with barbs on either side. These are plumulaceous feathers, meaning that they are soft and bendable. In birds, these semiplumes are common along the head, neck, and upper back, and may be used for buoyancy and sensing vibrations. Crests on birds are generally used for display purposes. Cockatoos and their smaller cousins, cockatiels, are part of the parrot family Cacatuidae found in Australia, the Bismarck Archipelago and the Philippines, and are probably the most recognizable birds to feature crests. Cockatoos and cockatiels possess crests which may be raised or lowered at will. Their crests are used to communicate with fellow members of their species, or as a fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Display Feature
A courtship display is a set of display behaviors in which an animal, usually a male, attempts to attract a mate; the mate exercises choice, so sexual selection acts on the display. These behaviors often include ritualized movement ("dances"), vocalizations, mechanical sound production, or displays of beauty, strength, or agonistic ability. Male display In some species, males will perform ritualized movements to attract females. The male six-plumed bird-of-paradise ( ''Parotia lawesii'') exemplifies male courtship display with its ritualized "ballerina dance" and unique occipital and breast feathers that serve to stimulate the female visual system. In ''Drosophila subobscura,'' male courtship display is seen through the male's intricate wing scissoring patterns and rapid sidestepping. These stimulations, along with many other factors, result in subsequent copulation or rejection. In other species, males may exhibit courtship displays that serve as both visual and auditory st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermoregulatory
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation. The internal thermoregulation process is one aspect of homeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from thermal equilibrium with its environment (the study of such processes in zoology has been called physiological ecology). If the body is unable to maintain a normal temperature and it increases significantly above normal, a condition known as hyperthermia occurs. Humans may also experience lethal hyperthermia when the wet bulb temperature is sustained above for six hours. The opposite condition, when body temperature decreases below normal levels, is known as hypothermia. It results when the homeostatic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
