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Cochlear Aqueduct
Medial to the opening for the carotid canal and close to its posterior border, in front of the jugular fossa, is a triangular depression; at the apex of this is a small opening, the aquaeductus cochleae (or cochlear aqueduct, or aqueduct of cochlea), which lodges a tubular prolongation of the dura mater establishing a communication between the perilymphatic space and the subarachnoid space, and transmits a vein from 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. A core component of the cochlea is the Organ of Corti, the sensory or ... to join the internal jugular vein. Additional images File:Gray187.png, Base of skull. Inferior surface. References Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Bone
The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. The lower seven cranial nerves and the major vessels to and from the brain traverse the temporal bone. Structure The temporal bone consists of four parts— the squamous, mastoid, petrous and tympanic parts. The squamous part is the largest and most superiorly positioned relative to the rest of the bone. The zygomatic process is a long, arched process projecting from the lower region of the squamous part and it articulates with the zygomatic bone. Posteroinferior to the squamous is the mastoid part. Fused with the squamous and mastoid parts and between the sphenoid and occipital bones lies the petrous part, which is shaped like a pyramid. The tympanic part is relatively small and lies inferior to the squamous part, anterior to the mast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotid Canal
The carotid canal is a passageway in the temporal bone of the skull through which the internal carotid artery enters the middle cranial fossa from the neck. Structure The carotid canal is located within the middle cranial fossa, at the petrous part of the temporal bone. Anteriorly, it is limited by posterior margin of the greater wing of sphenoid bone. Posteromedially, it is limited by basilar part of occipital bone. It is divided in three parts, namely, ascending petrous, transverse petrous, and ascending cavernous parts. The carotid canal has two openings, namely internal and external openings. The internal opening is situated laterally to foramen lacerum. The external opening of the carotid canal is located posterolaterally to the foramen lacerum. Both internal and external openings of the carotid canal lies anterior to the jugular foramen, where the latter is located inside the posterior cranial fossa. The carotid canal is separated from middle ear and inner ear by a thin pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jugular Fossa
The jugular fossa is a deep depression in the inferior part of the temporal bone at the base of the skull. It lodges the bulb of the internal jugular vein. Structure The jugular fossa is located in the temporal bone, posterior to the carotid canal and the cochlear aqueduct. In the bony ridge dividing the carotid canal from the jugular fossa is the small inferior tympanic canaliculus for the passage of the tympanic branch of the glossopharyngeal nerve. In the lateral part of the jugular fossa is the mastoid canaliculus for the entrance of the auricular branch of the vagus nerve. Behind the jugular fossa is a quadrilateral area, the jugular surface, covered with cartilage in the fresh state, and articulating with the jugular process of the occipital bone. Variation The jugular fossa has variable depth and size in different skulls. Function The jugular fossa lodges the bulb of the internal jugular vein. Clinical significance Abnormally shaped jugular fossae may cause ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dura Mater
In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. The other two meningeal layers are the arachnoid mater and the pia mater. It envelops the arachnoid mater, which is responsible for keeping in the cerebrospinal fluid. It is derived primarily from the neural crest cell population, with postnatal contributions of the paraxial mesoderm. Structure The dura mater has several functions and layers. The dura mater is a membrane that envelops the arachnoid mater. It surrounds and supports the dural sinuses (also called dural venous sinuses, cerebral sinuses, or cranial sinuses) and carries blood from the brain toward the heart. Cranial dura mater has two layers called ''lamellae'', a superficial layer (also called the periosteal layer), which serves as the skull's inner periosteum, called the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perilymphatic Space
Perilymph is an extracellular fluid located within the inner ear. It is found within the scala tympani and scala vestibuli of the cochlea. The ionic composition of perilymph is comparable to that of plasma and cerebrospinal fluid. The major cation in perilymph is sodium, with the values of sodium and potassium concentration in the perilymph being 138 mM and 6.9 mM, respectively. It is also named Cotunnius' liquid and liquor cotunnii for Domenico Cotugno. Structure The inner ear has two major parts, the cochlea and the vestibular organ. They are connected in a series of canals in the temporal bone referred to as the bony labyrinth. The bone canals are separated by the membranes in parallel spaces referred to as the membranous labyrinth. The membranous labyrinth contains endolymph, and is surrounded by perilymph. The perilymph in the bony labyrinth serves as connection to the cerebrospinal fluid of the subarachnoid space via the perilymphatic duct. Composition Peri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subarachnoid Space
In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in the subarachnoid space between the arachnoid mater and the pia mater. The primary function of the meninges is to protect the central nervous system. Structure Dura mater The dura mater ( la, tough mother) (also rarely called ''meninx fibrosa'' or ''pachymeninx'') is a thick, durable membrane, closest to the skull and vertebrae. The dura mater, the outermost part, is a loosely arranged, fibroelastic layer of cells, characterized by multiple interdigitating cell processes, no extracellular collagen, and significant extracellular spaces. The middle region is a mostly fibrous portion. It consists of two layers: the endosteal layer, which lies closest to the skull, and the inner meningeal layer, which lies closer to the brain. It contains large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. A core component of the cochlea is the Organ of Corti, the sensory organ of hearing, which is distributed along the partition separating the fluid chambers in the coiled tapered tube of the cochlea. The name cochlea derives . Structure The cochlea (plural is cochleae) is a spiraled, hollow, conical chamber of bone, in which waves propagate from the base (near the middle ear and the oval window) to the apex (the top or center of the spiral). The spiral canal of the cochlea is a section of the bony labyrinth of the inner ear that is approximately 30 mm long and makes 2 turns about the modiolus. The cochlear structures include: * Three ''scalae'' or chambers: ** the vestibular duct or ''scala vestibuli'' (containing perilymph), which lies superior to the cochlear duct and abuts the oval window ** the ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Jugular Vein
The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the posterior compartment of the jugular foramen, at the base of the skull. It is somewhat dilated at its origin, which is called the ''superior bulb''. This vein also has a common trunk into which drains the anterior branch of the retromandibular vein, the facial vein, and the lingual vein. It runs down the side of the neck in a vertical direction, being at one end lateral to the internal carotid artery, and then lateral to the common carotid artery, and at the root of the neck, it unites with the subclavian vein to form the brachiocephalic vein (innominate vein); a little above its termination is a second dilation, the ''inferior bulb''. Above, it lies upon the rectus capitis lateralis, behind the internal carotid artery and the nerves passing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
