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Maxillary Sinus
The pyramid-shaped maxillary sinus (or antrum of Nathaniel Highmore (surgeon), Highmore) is the largest of the paranasal sinuses, located in the maxilla. It drains into the middle meatus of the noseHuman Anatomy, Jacobs, Elsevier, 2008, page 209-210 through the semilunar hiatus. It is located to the side of the nasal cavity, and below the orbit. Structure It is the largest air sinus in the body. It has a mean volume of about 10 ml. It is situated within the body of the maxilla, but may extend into its Maxilla, zygomatic and Maxilla, alveolar processes when large. It is pyramid-shaped, with the apex at the maxillary zygomatic process, and the base represented by the lateral nasal wall. It has three recesses: an alveolar recess pointed inferiorly, bounded by the alveolar process of the maxilla; a zygomatic recess pointed laterally, bounded by the zygomatic bone; and an infraorbital recess pointed superiorly, bounded by the inferior Orbital surface of the body of the maxilla, orbita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolar Process
The alveolar process () is the portion of bone containing the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The alveolar process is covered by gums within the mouth, terminating roughly along the line of the mandibular canal. Partially comprising compact bone, it is penetrated by many small openings for blood vessels and connective fibres. The bone is of clinical, phonetic and forensic significance. Terminology The term ''alveolar'' () ('hollow') refers to the cavities of the tooth sockets, known as dental alveoli. The alveolar process is also called the ''alveolar bone'' or ''alveolar ridge''. In phonetics, the term refers more specifically to the ridges on the inside of the mouth which can be felt with the tongue, either on roof of the mouth between the upper teeth and the hard palate or on the bottom of the mouth behind the lower teeth. The curved portion of the process is referred to as the alveolar arch. The alveolar bone proper, also ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postganglionic
In the autonomic nervous system, nerve fibers from the ganglion to the wikt:effector, effector organ are called postganglionic nerve fibers. Neurotransmitters The neurotransmitters of postganglionic fibers differ: * In the parasympathetic division, neurons are ''cholinergic''. That is to say acetylcholine is the primary neurotransmitter responsible for the communication between neurons on the parasympathetic nervous system, parasympathetic pathway. * In the sympathetic division, neurons are mostly ''adrenergic'' (that is, epinephrine and norepinephrine function as the primary neurotransmitters). Notable exceptions to this rule include the sympathetic innervation of sweat glands and Arrector pili muscle, arrectores pilorum muscles where the neurotransmitter at both pre and post ganglionic synapses is acetylcholine. Another notable structure is the medulla of the adrenal gland, where chromaffin cells function as modified post-ganglionic nerves. Instead of releasing epinephrine an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infraorbital Canal
The infraorbital canal is a canal found at the base of the orbit that opens on to the maxilla. It is continuous with the infraorbital groove and opens onto the maxilla at the infraorbital foramen. The infraorbital nerve and infraorbital artery travel through the canal. Structure One of the canals of the orbital surface of the maxilla, the infraorbital canal, opens just below the margin of the orbit, the area of the skull containing the eye and related structures. It should not be confused with the infraorbital foramen, with which it is continuous. Function It transmits the infraorbital nerve as well as infraorbital artery, both of which enter this canal at the infraorbital groove and after coursing through the maxillary sinus exit via the infraorbital foramen In human anatomy, the infraorbital foramen is one of two small holes in the skull's upper jawbone ( maxillary bone), located below the eye socket and to the left and right of the nose. Both holes are used for blood vesse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar Teeth
The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth", from ''mola'', millstone and ''dens'', tooth. Molars show a great deal of diversity in size and shape across the mammal groups. The third molar of humans is sometimes vestigial. Human anatomy In humans, the molar teeth have either four or five cusps. Adult humans have 12 molars, in four groups of three at the back of the mouth. The third, rearmost molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the front of the gum at about the age of 20, although this varies among individuals and populations, and in many cases the tooth is missing. The human mouth contains upper (maxillary) and lower (mandibular) molars. They are: maxillary first molar, maxillary second molar The maxillary second mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar (tooth)
The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth", from ''mola'', millstone and ''dens'', tooth. Molars show a great deal of diversity in size and shape across the mammal groups. The third molar of humans is sometimes vestigial. Human anatomy In humans, the molar teeth have either four or five cusps. Adult humans have 12 molars, in four groups of three at the back of the mouth. The third, rearmost molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the front of the gum at about the age of 20, although this varies among individuals and populations, and in many cases the tooth is missing. The human mouth contains upper (maxillary) and lower (mandibular) molars. They are: maxillary first molar, maxillary second molar, maxillary third mol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Superior Alveolar Nerve
The posterior superior alveolar nerves (also posterior superior dental nerves or posterior superior alveolar branches) are sensory branches of the maxillary nerve (CN V2). They arise within the pterygopalatine fossa as a single trunk. They run on or in the maxilla. They provide sensory innervation to the upper molar teeth and adjacent gum, and the maxillary sinus. Anatomy Origin The nerves arise from the trunk of the maxillary nerve (CN V2) within the pterygopalatine fossa just before it enters the infraorbital groove. The nerve arises as a single trunk which split into 2-3 nerves within the pterygopalatine fossa. Course The nerves exit the pterygopalatine fossa through the pterygomaxillary fissure. They pass within or upon the posterior wall of the maxilla. They descend on the tuberosity of the maxilla and give off several twigs to the gums and neighboring parts of the mucous membrane of the cheek. They then enter the alveolar canals on the infratemporal surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolar Canals
The alveolar canals are apertures in the center of the infratemporal surface of the maxilla. The alveolar canals transmit the posterior superior alveolar vessels and nerves A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called .... References Foramina of the skull {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Bone
The lacrimal bones are two small and fragile bones of the facial skeleton; they are roughly the size of the little fingernail and situated at the front part of the medial wall of the orbit. They each have two surfaces and four borders. Several bony landmarks of the lacrimal bones function in the process of lacrimation. Specifically, the lacrimal bones help form the nasolacrimal canal necessary for tear translocation. A depression on the anterior inferior portion of one bone, the lacrimal fossa, houses the membranous lacrimal sac. Tears, from the lacrimal glands, collect in this sac during excessive lacrimation. The fluid then flows through the nasolacrimal duct and into the nasopharynx. This drainage results in what is commonly referred to a runny nose during excessive crying or tear production. Injury or fracture of the lacrimal bone can result in posttraumatic obstruction of the lacrimal pathways. Structure Lateral or orbital surface The lateral or orbital surface is divided b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palatine Bone
In anatomy, the palatine bones (; derived from the Latin ''palatum'') are two irregular bones of the facial skeleton in many animal species, located above the uvula in the throat. Together with the maxilla, they comprise the hard palate. Structure The palatine bones are situated at the back of the nasal cavity between the maxilla and the pterygoid process of the sphenoid bone. They contribute to the walls of three cavities: the floor and lateral walls of the nasal cavity, the roof of the mouth, and the floor of the orbits. They help to form the pterygopalatine and pterygoid fossae, and the inferior orbital fissures. Each palatine bone somewhat resembles the letter L, and consists of a horizontal plate, a perpendicular plate, and three projecting processes—the pyramidal process, which is directed backward and lateral from the junction of the two parts, and the orbital and sphenoidal processes, which surmount the vertical part, and are separated by a deep notch, the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Nasal Concha
The inferior nasal concha (inferior turbinated bone or inferior turbinal/turbinate) is one of the three paired nasal conchae in the human nose, nose. It extends horizontally along the lateral wall of the nasal cavity and consists of a wikt:lamina, lamina of spongy bone, curled upon itself like a scroll, (''turbinate'' meaning inverted cone). The inferior nasal conchae are considered a pair of facial bones. As the air passes through the turbinates, the air is churned against these mucosa-lined bones in order to receive warmth, moisture and cleansing. Superior to inferior nasal concha are the middle nasal concha and superior nasal concha which both arise from the ethmoid bone, of the cranial portion of the skull. Hence, these two are considered as a part of the cranial bones. It has two surfaces, two borders, and two extremities. Structure Surfaces The medial surface is wikt:convex, convex, perforated by numerous apertures, and traversed by longitudinal grooves for the lodgem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uncinate Process Of Ethmoid Bone
In the ethmoid bone, a sickle shaped projection, the uncinate process, projects posteroinferiorly from the ethmoid labyrinth. Between the posterior edge of this process and the anterior surface of the ethmoid bulla, there is a two-dimensional space, resembling a crescent shape. This space continues laterally as a three-dimensional slit-like space - the ethmoidal infundibulum. This is bounded by the uncinate process, medially, the orbital lamina of ethmoid bone The orbital lamina of ethmoid bone (or lamina papyracea or orbital lamina) is a smooth, oblong, paper-thin bone plate which forms the lateral wall of the labyrinth of the ethmoid bone. It covers the middle and posterior ethmoidal cells, and forms ... (lamina papyracea), laterally, and the ethmoidal bulla, posterosuperiorly. This concept is easier to understand if one imagine the infundibulum as a prism so that its medial face is the hiatus semilunaris. The "lateral face" of this infundibulum contains the ostium of the max ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
