|
Lacrimal Groove
On the nasal surface of the body of the maxilla, in front of the opening of the sinus is a deep groove, the lacrimal groove (or lacrimal sulcus), which is converted into the nasolacrimal canal, by the lacrimal bone and inferior nasal concha; this canal opens into the inferior meatus of the nose and transmits the nasolacrimal duct The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards. The .... Additional images File:Gray191.png, Horizontal section of nasal and orbital cavities. References Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Bone
The lacrimal bone is a small and fragile bone of the facial skeleton; it is roughly the size of the little fingernail. It is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders. Several bony landmarks of the lacrimal bone function in the process of lacrimation or crying. Specifically, the lacrimal bone helps form the nasolacrimal canal necessary for tear translocation. A depression on the anterior inferior portion of the bone, the lacrimal fossa, houses the membranous lacrimal sac. Tears or lacrimal fluid, 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 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxilla
The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible (lower jaw), which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw. Structure In humans, the maxilla consists of: * The body of the maxilla * Four processes ** the zygomatic process ** the frontal process of maxilla ** the alveolar process ** the palatine process * three surfaces – anterior, posterior, medial * the Infraorbital foramen * the maxillary sinus * the incisive foramen Articulations Each maxilla articulates with nine bones: * two of the cranium: the frontal and ethmoid * seven of the face: the nasal, zygomatic, lacrimal, inferior n ... [...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 nose. It extends horizontally along the lateral wall of the nasal cavity and consists of a 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 convex, perforated by numerous apertures, and traversed by longitudinal grooves for the lodgement of vessels. The lateral surface is con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Meatus
In anatomy, the term nasal meatus can refer to any of the three meatuses (passages) through the skulls nasal cavity: the superior meatus (''meatus nasi superior''), middle meatus (''meatus nasi medius''), and inferior meatus (''meatus nasi inferior''). The nasal meatuses are located beneath each of the corresponding nasal conchae. In the case where a fourth, supreme nasal concha is present, there is a fourth supreme nasal meatus. Structure The superior meatus is the smallest of the three. It is a narrow cavity located obliquely below the superior concha. This meatus is short, lies above and extends from the middle part of the middle concha below. From behind, the sphenopalatine foramen opens into the cavity of the superior meatus and the meatus communicates with the posterior ethmoidal cells. Above and at the back of the superior concha is the sphenoethmoidal recess which the sphenoidal sinus opens into. The superior meatus occupies the middle third of the nasal cavity’s l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nasolacrimal Duct
The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards. The opening of the nasolacrimal duct into the inferior nasal meatus of the nasal cavity is partially covered by a mucosal fold ( valve of Hasner or ''plica lacrimalis''). Excess tears flow through the nasolacrimal duct which drains into the inferior nasal meatus. This is the reason the nose starts to run when a person is crying or has watery eyes from an allergy, and why one can sometimes taste eye drops. This is for the same reason when applying some eye drops it is often advised to close the nasolacrimal duct by pressing it with a finger to prevent the medicine from escaping the eye and having unwanted side effects elsewhere in the body as it will proceed through the canal to the Nasal Cavity. Like the lacrimal sac, the duct is lined by st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
