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Temporomandibular Joints
In anatomy, the temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral synovial articulation between the temporal bone of the skull above and the mandible below; it is from these bones that its name is derived. This joint is unique in that it is a bilateral joint that functions as one unit. Since the TMJ is connected to the mandible, the right and left joints must function together and therefore are not independent of each other. Structure The main components are the joint capsule, articular disc, mandibular condyles, articular surface of the temporal bone, temporomandibular ligament, stylomandibular ligament, sphenomandibular ligament, and lateral pterygoid muscle. Capsule The articular capsule (capsular ligament) is a thin, loose envelope, attached above to the circumference of the mandibular fossa and the articular tubercle immediately in front; below, to the neck of the condyle of the mandible. Its loose attachment to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint
A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw-Hill Connect. Webp.274/ref> They are constructed to allow for different degrees and types of movement. Some joints, such as the knee, elbow, and shoulder, are self-lubricating, almost frictionless, and are able to withstand compression and maintain heavy loads while still executing smooth and precise movements. Other joints such as sutures between the bones of the skull permit very little movement (only during birth) in order to protect the brain and the sense organs. The connection between a tooth and the jawbone is also called a joint, and is described as a fibrous joint known as a gomphosis. Joints are classified both structurally and functionally. Classification The number of joints depends on if sesamoids are included, age of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternoclavicular Joint
The sternoclavicular joint or sternoclavicular articulation is a synovial saddle joint between the manubrium of the sternum, and the clavicle, as well as the first rib. The joint possesses a joint capsule, and an articular disk, and is reinforced by multiple ligaments. Structure The joint is structurally classed as a synovial plane joint and functionally classed as a diarthrosis and multiaxial joint. It is composed of two portions separated by an articular disc of fibrocartilage. The joint is formed by the sternal end of the clavicle, the clavicular notch (the superior and lateral part of the sternum), and (the superior surface of) the cartilage of the first rib (visible from the outside as the suprasternal notch). The articular surface of the clavicle is larger than that of the sternum, and is invested with a layer of cartilage, which is considerably thicker than that of the sternum. The joint receives arterial supply via branches of the internal thoracic artery, and of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auriculotemporal
The auriculotemporal nerve is a branch of the mandibular nerve (CN V3) that runs with the superficial temporal artery and vein, and provides sensory innervation to various regions on the side of the head. Structure Origin The auriculotemporal nerve arises from the mandibular nerve (CN V3). The mandibular nerve is a branch of the trigeminal nerve (CN V), and the mandibular nerve exits the skull through the foramen ovale.Gray's Anatomy for Students, 2nd edition (2010), Drake Vogel and Mitchell, Elseview These roots encircle the middle meningeal artery (a branch of the mandibular part of the maxillary artery, which is in turn a terminal branch of the external carotid artery). The roots encompass the middle meningeal artery then converge to form a single nerve. Course The auriculotemporal nerve passes between the neck of the mandible and the sphenomandibular ligament. It gives off parotid branches and then turns superiorly, posterior to its head and moving anteriorly, giv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malleus
The malleus, or hammer, is a hammer-shaped small bone or ossicle of the middle ear. It connects with the incus, and is attached to the inner surface of the eardrum. The word is Latin for 'hammer' or 'mallet'. It transmits the sound vibrations from the eardrum to the ''incus'' (anvil). Structure The malleus is a bone situated in the middle ear. It is the first of the three ossicles, and attached to the tympanic membrane. The head of the malleus is the large protruding section, which attaches to the incus. The head connects to the neck of malleus. The bone continues as the handle (or manubrium) of malleus, which connects to the tympanic membrane. Between the neck and handle of the malleus, lateral and anterior processes emerge from the bone. The bone is oriented so that the head is superior and the handle is inferior. Development Embryologically, the malleus is derived from the first pharyngeal arch along with the ''incus''. It grows from Meckel's cartilage. Function The malleu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Ear
The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea (of the inner ear). The mammalian middle ear contains three ossicles, which transfer the vibrations of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear is also known as the tympanic cavity and is surrounded by the tympanic part of the temporal bone. The auditory tube (also known as the Eustachian tube or the pharyngotympanic tube) joins the tympanic cavity with the nasal cavity (nasopharynx), allowing pressure to equalize between the middle ear and throat. The primary function of the middle ear is to efficiently transfer acoustic energy from compression waves in air to fluid–membrane waves within the cochlea. Structure Ossicles The middle ear contains three tiny bones known as the ossicles: '' malleus'', '' incus'', and ''stapes''. The ossicles were given their Latin names for their distinctive shapes; they ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lingula Of Mandible
The lingula of the mandible is a prominent bony ridge on the medial side of the mandible. It is next to the mandibular foramen. It gives attachment to the sphenomandibular ligament. Structure The lingula of the mandible is a prominent bony ridge on the medial side of the mandible. It is next to the mandibular foramen. It has a notch from which the mylohyoid groove originates. It gives attachment to the sphenomandibular ligament The sphenomandibular ligament (internal lateral ligament) is one of the three ligaments of the temporomandibular joint. It is situated medially to - and generally separate from - the articular capsule of the joint. Superiorly, it is attached to the .... Variation The lingula of the mandible can take many shapes, including triangular, truncated, and nodular. In a majority of people, this shape is symmetrical. See also * Lingula References External links * http://ect.downstate.edu/courseware/haonline/labs/l22/os2009.htm * * Bones of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spine Of The Sphenoid Bone
The sphenoidal spine (Latin: "''spina angularis''") is a downwardly directed process at the apex of the great wings of the sphenoid bone that serves as the origin of the sphenomandibular ligament. Additional images File:Spine of sphenoid bone.png, Base of skull The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the endocranium and the lower parts of the calvaria. Structure Structures found at the base of the skull are for .... Inferior surface. Spine of sphenoid bone marked with black circle References External links * - "Schematic view of key landmarks of the infratemporal fossa." * Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenomandibular Ligament
The sphenomandibular ligament (internal lateral ligament) is one of the three ligaments of the temporomandibular joint. It is situated medially to - and generally separate from - the articular capsule of the joint. Superiorly, it is attached to the spine of the sphenoid bone; inferiorly, it is attached to the lingula of mandible. The SML acts to limit inferior-ward movement of the mandible. The SML is derived from Meckel's cartilage. Anatomy The SML is a flat, thin band. It widens/broadens inferiorlybefore as it reaches its inferior attachment, measuring about 12 mm in width on average at the point of its inferior attachment. Attachments Superiorly, the SML is attached to the spine of the sphenoid bone (spina angularis. Inferiorly, it is attached at to lingula of mandible (which occurs just proximally to the mandibular foramen). Anatomical relations The lateral pterygoid muscle, auriculotemporal nerve, and the maxillary artery and maxillary vein are situated laterally to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of The Mandible
__NOTOC__ The angle of the mandible (gonial angle) is located at the posterior border at the junction of the lower border of the ramus of the mandible. The angle of the mandible, which may be either inverted or everted, is marked by rough, oblique ridges on each side, for the attachment of the masseter laterally, and the pterygoideus internus (medial pterygoid muscle) medially; the stylomandibular ligament is attached to the angle between these muscles. The forensic term for the midpoint of the mandibular angle is the gonion. The gonion is a cephalometric landmark located at the lowest, posterior, and lateral point on the angle. This site is at the apex of the maximum curvature of the mandible, where the ascending ramus becomes the body of the mandible. The mandibular angle has been named as a forensic tool for gender determination, but some studies have called into question whether there is any significant sex difference in humans in the angle. See also *Ohngren's line Add ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styloid Process (temporal)
The temporal styloid process is a slender bony process of the temporal bone extending downward and forward from the undersurface of the temporal bone just below the ear. The styloid process gives attachments to several muscles, and ligaments. Structure The styloid process is a slender and pointed bony process of the temporal bone projecting anteroinferiorly from the inferior surface of the temporal bone just below the ear. Its length normally ranges from just under 3 cm to just over 4 cm. It is usually nearly straight, but may be curved in some individuals. Its ''proximal'' (''tympanohyal'') ''part'' is ensheathed by the tympanic part of the temporal bone ''(vaginal process), whereas'' its ''distal (stylohyal)'' ''part'' gives attachment to several structures. Attachments The styloid process gives attachments to several muscles, and ligaments. It serves as an anchor point for several muscles associated with the tongue and larynx. * stylohyoid ligament * stylomandibu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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