Categories: Auditory system | Skeletal system | Skull This article or section may be confusing for some readers, and should be edited to be clearer or more simplified. ... The auditory system is the sensory system for the sense of hearing. ... It has been suggested that Equilibrioception be merged into this article or section. ... The outer ear is the external portion of the ear. ... The pinna (Latin for feather) is the visible part of the ear that resides outside of the head (this may also be referred to as the auricle or auricula). ... A left human ear. ... On the pinna, a curved prominence of cartilage, parallel with and in front of the helix, is called the antihelix, also known as the anthelix; this divides above into two crura, between which is a triangular depression, the fossa triangularis. ... In front of the concha, and projecting backward over the meatus, is a small pointed eminence, the tragus, so called from its being generally covered on its under surface with a tuft of hair, resembling a goat’s beard. ... Opposite the tragus, and separated from it by the intertragic notch, is a small tubercle, the antitragus. ... On the ear of humans and many other animals, the earlobe (lobulus auriculæ, sometimes simply lobe or lobule) is the soft lower part of the external ear or pinna. ... The ear canal (external auditory meatus, external acoustic meatus), is a tube running from the outer ear to the middle ear. ... The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. ... The tympanic membrane, colloquially known as the eardrum, is a thin membrane that separates the external ear from the middle ear. ... The ossicles (also called auditory ossicles) are the three smallest bones in the human body. ... The malleus is hammer-shaped small bone or ossicle of the middle ear which connects with the incus and is attached to the inner surface of the eardrum. ... This article refers to a bone in the mammalian ear. ... The stapedius is the smallest striated muscle in the human body. ... The tensor tympani muscle arises from the auditory tube and inserts onto the handle of the malleus, damping down vibration in the ossicles and so reducing the amplitude of sounds. ... The Eustachian tube (or auditory tube) is a tube that links the pharynx to the middle ear. ... The base of the cartilaginous portion of the Eustachian tube lies directly under the mucous membrane of the nasal part of the pharynx, where it forms an elevation, the torus tubarius or cushion, behind the pharyngeal orifice of the tube. ... Inner ear The inner ear is the bony labyrinth, a system of passages comprising two main functional parts: the organ of hearing, or cochlea and the vestibular apparatus, the organ of balance that consists of three semicircular canals and the vestibule. ... For more uses of the word labyrinth, see Labyrinth (disambiguation) The labyrinth is a system of fluid passages in the inner ear, including both the cochlea which is part of the auditory system, and the vestibular system which provides the sense of balance. ... The bony labyrinth (osseous labyrinth) consists of three parts: vestibule semicircular canals cochlea These are cavities hollowed out of the substance of the bone, and lined by periosteum; they contain a clear fluid, the perilymph, in which the membranous labyrinth is situated. ... This is a page about the part of the ear. ... The membranous labyrinth is lodged within the bony labyrinth, and has the same general form; it is, however, considerably smaller, and is partly separated from the bony walls by a quantity of fluid, the perilymph. ... The helicotrema is the part of the cochlear labyrinth where the scala tympani and the scala vestibuli meet. ... The round window is one of two membranes that separates the inner ear from the middle ear. ... The cochlea is the auditory portion of the inner ear. ... The spiral ganglion is the group of nerve cells that serve the sense of hearing by sending a representation of sound from the cochlea to the brain. ... The modiolus is a conical shaped central axis in the cochlea. ... The cochlear duct (or scala media) is an endolymph filled cavity inside the cochlea, located in between the scala tympani and the scala vestibuli, separated by the basilar membrane and Reissners membrane (the vestibular membrane) respectively. ... Endolymph is the fluid contained in the membranous labyrinth of the inner ear. ... The upper portion of the spiral ligament contains numerous capillary loops and small blood vessels, and is termed the stria vascularis. ... The periosteum, forming the outer wall of the ductus cochlearis, is greatly thickened and altered in character, and is called the spiral ligament. ... The organ of Corti is the organ in the inner ear of mammals that contains auditory sensory cells, or hair cells. // Structure and function It has highly specialized structures that respond to fluid-borne vibrations in the cochlea with a shearing vector in the hairs of some cochlear hair cells. ... Scala vestibuli is a perilymph filled cavity inside the cochlea of the inner ear. ... Scala tympani is the name of one of the perilymph filled cavities in the cochlear labyrinth. ... Perilymph is a fluid located within the cochlea (part of the ear) in 2 of its 3 muscles; the scala typmani and scala vestibuli. ... Reissners membrane is a membrane inside the cochlea of the inner ear, it separates scala media from scala vestbuli and together with the basilar membrane it creates a compartment in the cochlea filled with perilymph, which is important for the function of the organ of Corti inside the scala... Cross section of the cochlea. ... Covering the sulcus spiralis internus and the spiral organ of Corti is the tectorial membrane, which is attached to the limbus laminae spiralis close to the inner edge of the vestibular membrane. ... The organ of Corti is the organ in the inner ear of mammals that contains auditory sensory cells, or hair cells. // Structure and function It has highly specialized structures that respond to fluid-borne vibrations in the cochlea with a shearing vector in the hairs of some cochlear hair cells. ... Hair cells are the sensory cells of both the auditory system and the vestibular system in all vertebrates. ... Section through the spiral organ of Corti. ... The basilar crest gives attachment to the outer edge of the basilar membrane; immediately above the crest is a concavity, the sulcus spiralis externus. ... On the upper plate of that part of the lamina which is outside the vestibular membrane, the periosteum is thickened to form the limbus laminæ spiralis, this ends externally in a concavity, the sulcus spiralis internus, which represents, on section, the form of the letter C. Histology at uc. ... The osseous spiral lamina consists of two plates of bone, and between these are the canals for the transmission of the filaments of the acoustic nerve. ... It has been suggested that Equilibrioception be merged into this article or section. ... The utricle, larger than the saccule, is of an oblong form, compressed transversely, and occupies the upper and back part of the vestibule, lying in contact with the recessus ellipticus and the part below it. ... The portion of the utricle which is lodged in the recess forms a sort of pouch or cul-de-sac, the floor and anterior wall of which are thickened, and form the macula of utricle, which receives the utricular filaments of the acoustic nerve. ... Categories: Stub ... The saccule is the smaller of the two vestibular sacs; it is globular in form, and lies in the recessus sphæricus near the opening of the scala vestibuli of the cochlea. ... From the posterior wall of the saccule a canal, the ductus endolymphaticus, is given off; this duct is joined by the ductus utriculosaccularis, and then passes along the aquaeductus vestibuli and ends in a blind pouch, the endolymphatic sac, on the posterior surface of the petrous portion of the temporal... From the posterior wall of the saccule a canal, the endolymphatic duct, is given off; this duct is joined by the ductus utriculosaccularis, and then passes along the aquaeductus vestibuli and ends in a blind pouch (saccus endolymphaticus) on the posterior surface of the petrous portion of the temporal bone... A kinocilium is a special structure connected to the hair cells of the inner ears cochlea. ... An otolith, (oto-, ear + lithos, a stone), also called statoconium[1] or otoconium is a structure in the saccule or utricle of the inner ear, specifically in the vestibular labyrinth. ... inner ear illustration showing semicircular canal, hair cells, ampulla, cupula, vestibular nerve, & fluid The semicircular canals are three half-circular, interconnected tubes located inside each ear that are the equivalent of three gyroscopes located in three planes perpendicular (at right angles) to each other. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... The posterior semicircular canal, vertical like the superior, is directed backward, nearly parallel to the posterior surface of the petrous bone; it is the longest of the three canals, measuring from 18 to 22 mm. ... The lateral or horizontal canal (external semicircular canal) is the shortest of the three canals. ... The cupula forms the apex of the cochlea. ... The bony semicircular canals are three in number, superior, posterior, and lateral, and are situated above and behind the vestibule. ... This article does not cite any references or sources. ... The human brain In animals, the brain (enkephalos) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... The Cochlear nerve (n. ... The vestibulocochlear nerve (also known as the auditory or acoustic nerve) is the eighth of twelve cranial nerves, and is responsible for transmitting sound and equilibrium (balance) information from the inner ear to the brain. ... The cochlear nuclei consist of: (a) the dorsal cochlear nucleus, corresponding to the tuberculum acusticum on the dorso-lateral surface of the inferior peduncle; and (b) the ventral or accessory cochlear nucleus, placed between the two divisions of the nerve, on the ventral aspect of the inferior peduncle. ... For the cerebellar structure, see Dentate nucleus. ... The lateral lemniscus is a tract of axons in the brainstem that carries information about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain. ... The paired inferior colliculi together with the superior colliculi form the eminences of the corpora quadrigemina. ... The medial geniculate nucleus is a nucleus of the thalamus that acts as a relay for auditory information. ... The primary auditory cortex is the region of the brain that is responsible for processing of auditory (sound) information. ... This article is about the skeletal organs. ... The vertebral column seen from the side Different regions (curvatures) of the vertebral column The vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen. ... A diagram of a thoracic vertebra. ... In vertebrates, cervical vertebrae (singular: vertebra) are those vertebrae immediately behind (caudal to) the skull. ... In anatomy, the atlas (C1) is the topmost (first) cervical vertebra of the spine. ... In anatomy, the second cervical vertebra (C2) of the spine is named the axis or epistropheus. ... The most distinctive characteristic of the seventh cervical vertebra is the existence of a long and prominent spinous process, hence the name vertebra prominens. ... A typical thoracic vertebra The thoracic vertebrae (vertebrae thoracales) compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. ... The lumbar vertebrae are the largest segments of the movable part of the vertebral column, and are characterized by the absence of the foramen transversarium within the transverse process, and by the absence of facets on the sides of the body. ... For the record label, see Sacrum Torch. ... The coccyx is formed of up to five vertebrae. ... Male Chest The chest is a part of the anatomy of humans and various other animals. ... The sternum (from Greek στέρνον, sternon, chest) or breastbone is a long, flat bone located in the center of the thorax (chest). ... The human rib cage. ... For other uses of Skull, see Skull (disambiguation). ... The occipital bone, a saucer-shaped membrane bone situated at the back and lower part of the cranium, is trapezoid in shape and curved on itself. ... The parietal bones (os parietale) are bones in the human skull and form, by their union, the sides and roof of the cranium. ... The frontal bone (os frontale, TA: A02. ... The temporal bones (os temporales) are situated at the sides and base of the skull. ... The sphenoid bone (from Greek sphenoeides, wedgelike) is a bone situated at the base of the skull in front of the temporals and basilar part of the occipital. ... Your skull is in your back (this is obviously not true, I was just testing the website to see if it really works) The ethmoid bone (os ethmoidale) is a bone in the skull that separates the nasal cavity from the brain. ... For other uses of Skull, see Skull (disambiguation). ... The Nasal Bones (Ossa Faciei & Ossa Nasalia) are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, the bridge of the nose. ... The maxillae are the largest bones of the face, except for the mandible, and form, by their union, the whole of the upper jaw. ... The lacrimal bone (Os Lacrimale), the smallest and most fragile bone of the face, is situated at the front part of the medial wall of the orbit . ... The zygomatic bone (malar bone) is a paired bone of the human skull. ... The palatine bone is a bone situated at the back part of the nasal cavity between the maxilla and the pterygoid process of the sphenoid. ... The inferior nasal concha (Inferior Turbinated Bone) extends horizontally along the lateral wall of the nasal cavity [Fig. ... The vomer bone is one of the unpaired facial bones of the skull. ... The mandible (from Latin mandibŭla, jawbone) or inferior maxillary bone is, together with the maxilla, the largest and strongest bone of the face. ... The hyoid bone (Os Hyoideum; Lingual Bone) is a bone in the human neck, not articulated to any other bone; it is supported by the muscles of the neck and in turn supports the root of the tongue. ... The hyoid bone (Os Hyoideum; Lingual Bone) is a bone in the human neck, not articulated to any other bone; it is supported by the muscles of the neck and in turn supports the root of the tongue. ... The greater cornua project backward from the lateral borders of the body; they are flattened from above downward and diminish in size from before backward; each ends in a tubercle to which is fixed the lateral hyothyroid ligament. ... The hyoid bone (Lingual Bone) is a bone in the human neck, not articulated to any other bone; it is supported by the muscles of the neck and in turn supports the root of the tongue. ... The body of hyoid bone or central part is of a quadrilateral form. ... In humans, the upper limb is an anatomical term for the limb that is attached to the pectoral girdle. ... The pectoral girdle is the set of bones which connect the upper limb to the axial skeleton on each side. ... Collarbone and collar bone redirect here. ... Left scapula - front view () Left scapula - rear view () In anatomy, the scapula, or shoulder blade, is the bone that connects the humerus (arm bone) with the clavicle (collar bone). ... Look up ARM in Wiktionary, the free dictionary. ... The humerus is a long bone in the arm or fore-legs (animals) that runs from the shoulder to the elbow. ... The ulna (Elbow Bone) [Figs. ... The radius is the bone of the forearm that extends from the outside of your limb to your phlangx (lateral) of the elbow to the thumb side of the wrist. ... For other uses, see Hand (disambiguation). ... This article is about Carpal bones. ... The scaphoid bone of the wrist is found on the thumb side of the hand, within the anatomical snuffbox. ... The lunate bone (os lunatum; semilunar bone) is a bone in the human hand that may be distinguished by its deep concavity and crescentic outline. ... The triquetral bone (also called triquetral, os triquetrum, cuneiform bone, pyramidal bone, cubital bone, os pyramidale, os triangulare, three-cornered bone, and triangular bone) is a type of carpal bone. ... The left pisiform bone. ... The trapezium is a bone in the human hand. ... In human anatomy, the trapezoid bone (lesser multangular bone; os multangulum minus) is a bone in the hands. ... The capitate bone (os capitatum; os magnum) is a bone in the human hand. ... The hamate bone (os hamatum; unciform bone) is a bone in the human hand that may be readily distinguished by its wedge-shaped form, and the hook-like process which projects from its volar surface. ... The metacarpus is the intermediate part of the hand skeleton that is located between the fingers distally and the carpus which forms the connection to the forearm. ... Proximal phalanges are bones found in the limbs of most vertebrates. ... Intermediate phalanges are bones found in the limbs of most vertebrates. ... Distal phalanges are bones found in the limbs of most vertebrate skeletons. ... In humans, the lower limb is an anatomical term for the limb that is attached to the pelvic girlde, what is commonly referred to as the leg. ... Human male pelvis, viewed from front Human female pelvis, viewed from front The pelvis is the bony structure located at the base of the spine (properly known as the caudal end). ... The pelvis (pl. ... The ilium of the pelvis is divisible into two parts, the body and the ala; the separation is indicated on the internal surface by a curved line, the arcuate line, and on the external surface by the margin of the acetabulum. ... The ischium forms the lower and back part of the hip bone. ... The pubis, the anterior part of the hip bone, is divisible into a body, a superior and an inferior ramus. ... Diagram of an insect leg A leg is the part of an animals body that supports the rest of the animal above the ground and is used for locomotion. ... The femur or thigh bone is the longest, most voluminous, and strongest bone of the mammalian bodies. ... The patella or kneecap is a thick, triangular bone which articulates with the femur and covers and protects the front of the knee joint. ... For other uses see fibula (disambiguation) The fibula or calf bone is a bone placed on the lateral side of the tibia, with which it is connected above and below. ... This article is about the vertebrate bone. ... For other uses, see Foot (disambiguation). ... FIG. 268– Bones of the right foot. ... The calcaneus is the large bone making up the heel of the human foot. ... FIG. 270– Left talus, from above. ... The navicular bone occurs in human and horse anatomy. ... There are three cuneiform bones in the human foot: the medial cuneiform, the intermediate cuneiform and the lateral cuneiform. ... The cuboid bone is one of seven Tarsal bones. ... The metatarsus consists of the five long bones of the foot, which are numbered from the medial side (ossa metatarsalia I.-V.); each presents for examination a body and two extremities. ... Proximal phalanges are bones found in the limbs of most vertebrates. ... Intermediate phalanges are bones found in the limbs of most vertebrates. ... Distal phalanges are bones found in the limbs of most vertebrate skeletons. ... The ossicles (also called auditory ossicles) are the three smallest bones in the human body. ... The malleus is hammer-shaped small bone or ossicle of the middle ear which connects with the incus and is attached to the inner surface of the eardrum. ... This article refers to a bone in the mammalian ear. ...