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Lagena (anatomy)
The lagena (from Greek λάγηνος ''lágēnos'' 'flask') is a structure found in humans and in animals. In human anatomy In the ear, the extremities of the ductus cochlearis are closed; the upper is termed the lagena and is attached to the cupula at the upper part of the helicotrema; the lower is lodged in the recessus cochlearis of the vestibule. In fish and amphibians The lagena is part of the vestibular system in fish and amphibians. It contains the otolith An otolith (, ' ear + , ', a stone), also called otoconium, statolith, or statoconium, is a calcium carbonate structure in the saccule or utricle (ear), utricle of the inner ear, specifically in the vestibular system of vertebrates. The saccule ...s ''asterisci''. In fish, the lagena is implicated in hearing and the registration of vertical linear acceleration,Webb, Jacqueline F./Richard R. Fay/Arthur N. Popper (Eds.): ''Fish Bioacoustics'', Springer, 2008, p. 23. in amphibians is the latter only. Reference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ductus Cochlearis
In anatomy and physiology, a duct is a circumscribed channel leading from an exocrine gland or organ. Types of ducts Examples include: Duct system As ducts travel from the acinus which generates the fluid to the target, the ducts become larger and the epithelium becomes thicker. The parts of the system are classified as follows: Some sources consider "lobar" ducts to be the same as "interlobar ducts", while others consider lobar ducts to be larger and more distal from the acinus. For sources that make the distinction, the interlobar ducts are more likely to classified with simple columnar epithelium (or pseudostratified epithelium), reserving the stratified columnar for the lobar ducts. File:Gray1025.png, Section of submaxillary gland of kitten. Duct semidiagrammatic. X 200. File:Gray1173.png, Section of portion of mamma. Intercalated duct The intercalated duct, also called intercalary duct (ducts of Boll), is the portion of an exocrine gland leading directly from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochlear Cupula
The cochlear cupula is a structure in the cochlea The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus (cochlea), modiolus. A core component of the cochlea is the organ of Cort .... It is the apex of the cochlea. The bony canal of the cochlea takes two and three-quarter turns around the modiolus. The modiolus is about 35 mm in length, and diminishes gradually in diameter from the base to the summit, where it terminates in the cupula. The cupula points towards the anterosuperior area of the medial wall of the tympanic cavity. References Auditory system {{anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicotrema
The helicotrema (from elixmeaning coil and rēmameaning hole) is the part of the cochlear labyrinth where the scala tympani and the scala vestibuli meet. It is the main component of the cochlear apex. The hair cells near this area best detect low frequency sounds. Structure The helicotrema is a part of the cochlear labyrinth where the scala tympani and the scala vestibuli meet. It is the main component of the cochlear apex. Function The helicotrema connects the scala tympani and the scala vestibuli. This allows fluid to move between the two. It slightly impedes the travel of sound. The hair cells near this area best detect low frequency sounds. Clinical significance The hair cells near the helicotrema are at higher risk of acoustic trauma than those in most other parts of the cochlea. It is also important during ear surgery. When pressure is placed on the perilymph in the cochlea, it reduces pressure and prevents damage to the organ of Corti The organ of Corti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestibule Of The Ear
The vestibule is the central part of the bony labyrinth in the inner ear, and is situated medial to the eardrum, behind the cochlea, and in front of the three semicircular canals. The name comes from the Latin ', literally an entrance hall. Structure The vestibule is somewhat oval in shape, but flattened transversely; it measures about 5 mm from front to back, the same from top to bottom, and about 3 mm across. In its lateral or tympanic wall is the oval window, closed, in the fresh state, by the base of the stapes and annular ligament. On its medial wall, at the forepart, is a small circular depression, the recessus sphæricus, which is perforated, at its anterior and inferior part, by several minute holes (macula cribrosa media) for the passage of filaments of the acoustic nerve to the saccule; and behind this depression is an oblique ridge, the crista vestibuli, the anterior end of which is named the pyramid of the vestibule. This ridge bifurcates below to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestibular System
The vestibular system, in vertebrates, is a sensory system that creates the sense of balance and spatial orientation for the purpose of coordinating motor coordination, movement with balance. Together with the cochlea, a part of the auditory system, it constitutes the labyrinth of the inner ear in most Mammal, mammals. As movements consist of rotations and translations, the vestibular system comprises two components: the semicircular canals, which indicate Angular acceleration, rotational movements; and the otoliths, which indicate Acceleration, linear accelerations. The vestibular system sends signals primarily to the neural structures that control eye movement; these provide the anatomical basis of the vestibulo-ocular reflex, which is required for clear vision. Signals are also sent to the muscles that keep an animal upright and in general control Neutral spine, posture; these provide the anatomical means required to enable an animal to maintain its desired position in space. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otolith
An otolith (, ' ear + , ', a stone), also called otoconium, statolith, or statoconium, is a calcium carbonate structure in the saccule or utricle (ear), utricle of the inner ear, specifically in the vestibular system of vertebrates. The saccule and utricle, in turn, together make the ''otolith organs''. These organs are what allows an organism, including humans, to perceive linear acceleration, both horizontally and vertically (gravity). They have been identified in both extinct and extant vertebrates. Counting the annual growth rings on the otoliths is a common technique in estimating the age of fish. Description Endolymphatic infillings such as otoliths are structures in the saccule and Utricle (ear), utricle of the inner ear, specifically in the Labyrinth (inner ear), vestibular labyrinth of all vertebrates (fish, amphibians, reptiles, mammals and birds). In vertebrates, the saccule and utricle together make the ''otolith organs''. Both statoconia and otoliths are used as gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
