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Encyclopedia > Petrous portion
Petrous portion
Left temporal bone. Outer surface.
Diagrammatic view of the fundus of the right internal acoustic meatus. (Testut.) 1. Crista falciformis. 2. Area facialis, with (2’) internal opening of the facial canal. 3. Ridge separating the area facialis from the area cribrosa superior. 4. Area cribrosa superior, with (4’) openings for nerve filaments. 5. Anterior inferior cribriform area, with (5’) the tractus spiralis foraminosus, and (5’’) the canalis centralis of the cochlea. 6. Ridge separating the tractus spiralis foraminosus from the area cribrosa media. 7. Area cribrosa media, with (7’) orifices for nerves to saccule. 8. Foramen singulare.
Latin pars petrosa (pyramis)
Gray's subject #34 142
System
Precursor {{{Precursor}}}
MeSH [1]
Dorlands/Elsevier {{{DorlandsPre}}}/{{{DorlandsSuf}}}

The petrous portion of the temporal bone or pyramid is pyramidal and is wedged in at the base of the skull between the sphenoid and occipital. Directed medialward, forward, and a little upward, it presents for examination a base, an apex, three surfaces, and three angles, and contains, in its interior, the essential parts of the organ of hearing. The temporal bones (os temporales) are situated at the sides and base of the skull. ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ... Embryology is the branch of developmental biology that studies embryos and their development. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Elseviers logo Elsevier, the worlds largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. ... The temporal bones (os temporales) are situated at the sides and base of the skull. ...

Contents


Base

The base is fused with the internal surfaces of the squama and mastoid portion.


Apex

The apex, rough and uneven, is received into the angular interval between the posterior border of the great wing of the sphenoid and the basilar part of the occipital; it presents the anterior or internal orifice of the carotid canal, and forms the postero-lateral boundary of the foramen lacerum.


Surfaces

The anterior surface forms the posterior part of the middle fossa of the base of the skull, and is continuous with the inner surface of the squamous portion, to which it is united by the petrosquamous suture, remains of which are distinct even at a late period of life. It is marked by depressions for the convolutions of the brain, and presents six points for examination:

  1. near the center, an eminence (eminentia arcuata) which indicates the situation of the superior semicircular canal
  2. in front of and a little lateral to this eminence, a depression indicating the position of the tympanic cavity: here the layer of bone which separates the tympanic from the cranial cavity is extremely thin, and is known as the tegmen tympani
  3. a shallow groove, sometimes double, leading lateralward and backward to an oblique opening, the hiatus of the facial canal, for the passage of the greater superficial petrosal nerve and the petrosal branch of the middle meningeal artery
  4. lateral to the hiatus, a smaller opening, occasionally seen, for the passage of the lesser superficial petrosal nerve
  5. near the apex of the bone, the termination of the carotid canal, the wall of which in this situation is deficient in front
  6. above this canal the shallow trigeminal impression for the reception of the semilunar ganglion.

The posterior surface forms the front part of the posterior fossa of the base of the skull, and is continuous with the inner surface of the mastoid portion. Near the center is a large orifice, the internal acoustic meatus, the size of which varies considerably; its margins are smooth and rounded, and it leads into a short canal, about 1 cm. in length, which runs lateralward. It transmits the facial and acoustic nerves and the internal auditory branch of the basilar artery. The lateral end of the canal is closed by a vertical plate, which is divided by a horizontal crest, the crista falciformis, into two unequal portions [Fig. 4]. Each portion is further subdivided by a vertical ridge into an anterior and a posterior part. In the portion beneath the crista falciformis are three sets of foramina; one group, just below the posterior part of the crest, situated in the area cribrosa media, consists of several small openings for the nerves to the saccule; below and behind this area is the foramen singulare, or opening for the nerve to the posterior semicircular duct; in front of and below the first is the tractus spiralis foraminosus, consisting of a number of small spirally arranged openings, which encircle the canalis centralis cochleæ; these openings together with this central canal transmit the nerves to the cochlea. The portion above the crista falciformis presents behind, the area cribrosa superior, pierced by a series of small openings, for the passage of the nerves to the utricle and the superior and lateral semicircular ducts, and, in front, the area facians, with one large opening, the commencement of the canal for the facial nerve (aquæductus Fallopii). Behind the internal acoustic meatus is a small slit almost hidden by a thin plate of bone, leading to a canal, the aquæductus vestibuli, which transmits the ductus endolymphaticus together with a small artery and vein. Above and between these two openings is an irregular depression which lodges a process of the dura mater and transmits a small vein; in the infant this depression is represented by a large fossa, the subarcuate fossa, which extends backward as a blind tunnel under the superior semicircular canal. On the interior surface of the temporal bone, behind the rough surface of the apex, is the large circular aperture of the carotid canal, which ascends at first vertically, and then, making a bend, runs horizontally forward and medialward; it transmits into the cranium the internal carotid artery, and the... Near the center of the posterior surface of the temporal bone is a large orifice, the internal acoustic meatus (or internal auditory meatus), the size of which varies considerably; its margins are smooth and rounded, and it leads into a short canal, about 1 cm. ... The basilar artery is one of the arteries which the brain supplies with oxygen-rich blood. ... Otolith organ Utricle is also a fruit type, found in beet and dock. ...

  1. Crista falciformis.
  2. Area facialis, with (2’) internal opening of the facial canal.
  3. Ridge separating the area facialis from the area cribrosa superior.
  4. Area cribrosa superior, with (4’) openings for nerve filaments.
  5. Anterior inferior cribriform area, with (5’) the tractus spiralis foraminosus, and (5’’) the canalis centralis of the cochlea.
  6. Ridge separating the tractus spiralis foraminosus from the area cribrosa media.
  7. Area cribrosa media, with (7’) orifices for nerves to saccule.
  8. Foramen singulare.

The inferior surface is rough and irregular, and forms part of the exterior of the base of the skull. It presents eleven points for examination:

  1. near the apex is a rough surface, quadrilateral in form, which serves partly for the attachment of the Levator veli palatini and the cartilaginous portion of the auditory tube, and partly for connection with the basilar part of the occipital bone through the intervention of some dense fibrous tissue;
  2. behind this is the large circular aperture of the carotid canal, which ascends at first vertically, and then, making a bend, runs horizontally forward and medialward; it transmits into the cranium the internal carotid artery, and the carotid plexus of nerves;
  3. 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 aquæductus cochleæ, 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 to join the internal jugular;
  4. behind these openings is a deep depression, the jugular fossa, of variable depth and size in different skulls; it lodges the bulb of the internal jugular vein;
  5. 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;
  6. in the lateral part of the jugular fossa is the mastoid canaliculus for the entrance of the auricular branch of the vagus nerve;
  7. 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;
  8. extending backward from the carotid canal is the vaginal process, a sheath-like plate of bone, which divides behind into two laminæ; the lateral lamina is continuous with the tympanic part of the bone, the medial with the lateral margin of the jugular surface;
  9. between these laminæ is the styloid process, a sharp spine, about 2.5 cm. in length;
  10. between the styloid and mastoid processes is the stylomastoid foramen; it is the termination of the facial canal, and transmits the facial nerve and stylomastoid artery;
  11. situated between the tympanic portion and the mastoid process is the tympanomastoid fissure, for the exit of the auricular branch of the vagus nerve.

In the temporal bone, behind the openings for the carotid canal and the aquæductus cochleæ is a deep depression, the jugular fossa, of variable depth and size in different skulls; it lodges the bulb of the internal jugular vein. ... Between the styloid and mastoid processes is the stylomastoid foramen; it is the termination of the facial canal, and transmits the facial nerve and stylomastoid artery. ... The vagus nerve (or pneumogastric nerve) is the tenth of twelve paired cranial nerves, and is the only nerve that starts in the brainstem (within the medulla oblongata) and extends, through the jugular foramen, down below the head, to the abdomen. ...

Angles

The superior angle, the longest, is grooved for the superior petrosal sinus, and gives attachment to the tentorium cerebelli; at its medial extremity is a notch, in which the trigeminal nerve lies. The tentorium cerebelli (Latin: tent of the cerebellum) is an extension of the dura mater that seperates the cerebellum from the inferior portion of the occipital lobes. ... The trigeminal nerve is the fifth (V) cranial nerve, and carries sensory information from most of the face, as well as motor supply to the muscles of mastication (the muscles enabling chewing), tensor tympani (in the middle ear), and other muscles in the floor of the mouth, such as the...


The posterior angle is intermediate in length between the superior and the anterior. Its medial half is marked by a sulcus, which forms, with a corresponding sulcus on the occipital bone, the channel for the inferior petrosal sinus. Its lateral half presents an excavation—the jugular fossa—which, with the jugular notch on the occipital, forms the jugular foramen; an eminence occasionally projects from the center of the fossa, and divides the foramen into two.


The anterior angle is divided into two parts—a lateral joined to the squama by a suture (petrosquamous), the remains of which are more or less distinct; a medial, free, which articulates with the spinous process of the sphenoid.


At the angle of junction of the petrous part and the squama are two canals, one above the other, and separated by a thin plate of bone, the septum canalis musculotubarii (processus cochleariformis); both canals lead into the tympanic cavity.

  • The upper one (semicanalis m. tensoris tympani) transmits the Tensor tympani.
  • the lower one (semicanalis tubae auditivae) forms the bony part of the auditory tube.

The tympanic cavity, auditory ossicles, and internal ear, are described with the organ of hearing.


This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant. The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... An illustration from the 1918 edition Henry Grays Anatomy of the Human Body, commonly known as Grays Anatomy, is an anatomy textbook widely regarded as a classic work on human anatomy. ...

Cranial bones - edit

occipital bone: Foramen magnum | Squama occipitalis (Inion | Nuchal lines | Planum occipitale | Planum nuchale | Internal occipital protuberance | Sagittal sulcus | Internal occipital crest) | Lateral parts (Hypoglossal canal | Condyloid fossa | Condyloid canal | Jugular process | Jugular tubercle) | Basilar part (Pharyngeal tubercle) A hippopotamus skull A skull, or cranium, is a bony structure of Craniates which serves as the general framework for a head. ... The occipital bone [Fig. ... In anatomy, the foramen magum is the large hole through the occipital bone in the base of the skull, through which the medulla oblongata (an extension of the spinal cord) exits the skull vault. ... The inion is the most prominent projection of the occipital bone at the lower rear part of the skull. ... The nuchal lines are four curved lines on the external surface of the occipital bone: The upper, often faintly marked, is named the highest nuchal line, and to it the galea aponeurotica is attached. ... In the occipital bone, at the point of intersection of the four divisions of the cruciate eminence is the internal occipital protuberance. ... In the occipital bone, the lower division of the cruciate eminence is prominent, and is named the internal occipital crest; it bifurcates near the foramen magnum and gives attachment to the falx cerebelli; in the attached margin of this falx is the occipital sinus, which is sometimes duplicated. ... The lateral parts of the occipital bone are situated at the sides of the foramen magnum; on their under surfaces are the condyles for articulation with the superior facets of the atlas. ... The hypoglossal canal is a bony canal in the occipital bone of the skull that transmits the hypoglossal nerve from its point of entry near the medulla oblongata to its exit from the base of the skull near the jugular foramen. ... Behind either condyle of the lateral parts of occipital bone is a depression, the condyloid fossa (or condylar fossa), which receives the posterior margin of the superior facet of the atlas when the head is bent backward; the floor of this fossa is sometimes perforated by the condyloid canal, through... In the lateral parts of occipital bone, behind either condyle is a depression, the condyloid fossa, which receives the posterior margin of the superior facet of the atlas when the head is bent backward; the floor of this fossa is sometimes perforated by the condyloid canal (or condylar canal), through... In the lateral part of the occipital bone, extending lateralward from the posterior half of the condyle is a quadrilateral plate of bone, the jugular process, excavated in front by the jugular notch, which, in the articulated skull, forms the posterior part of the jugular foramen. ... The upper surface of the lateral parts of occipital bone presents an oval eminence, the jugular tubercle, which overlies the hypoglossal canal and is sometimes crossed by an oblique groove for the glossopharyngeal, vagus, and accessory nerves. ... The basilar part of the occipital bone extends forward and upward from the foramen magnum, and presents in front an area more or less quadrilateral in outline. ...


parietal bone: Parietal eminence | Temporal line | Parietal foramen The parietal bones (os parietale) are bones in the human skull and form, by their union, the sides and roof of the cranium. ... The external surface of the parietal bone is convex, smooth, and marked near the center by an eminence, the parietal eminence (parietal tuber), which indicates the point where ossification commenced. ... At the back part of the parietal bone and close to the upper or sagittal border is the parietal foramen, which transmits a vein to the superior sagittal sinus, and sometimes a small branch of the occipital artery; it is not constantly present, and its size varies considerably. ...


frontal bone: Squama frontalis (Frontal suture | Frontal eminence | Superciliary arches | Glabella | Supraorbital foramen | Zygomatic process | Sagittal sulcus | Frontal crest | Foramen cecum) | Pars orbitalis (Frontal sinus | Frontonasal duct) The frontal bone (os frontale, TA: A02. ... The frontal suture (sutura frontalis) is a dense connective tissue structure that divides the two halves of the frontal bone of the skull in infants and children. ... On the frontal bone, on either side of the frontal suture, about 3 cm. ... The glabella is the space between the eyebrows and above the nose. ... The internal surface of the squama frontalis of the frontal bone is concave and presents in the upper part of the middle line a vertical groove, the sagittal sulcus, the edges of which unite below to form a ridge, the frontal crest; the sulcus lodges the superior sagittal sinus, while... The frontal crest of the frontal bone ends below in a small notch which is converted into a foramen, the foramen cecum, by articulation with the ethmoid. ... The orbital or horizontal part of the frontal bone (pars orbitalis) consists of two thin triangular plates, the orbital plates, which form the vaults of the orbits, and are separated from one another by a median gap, the ethmoidal notch. ... ... The frontal air sinuses are lined by mucous membrane, and each communicates with the corresponding nasal cavity by means of a passage called the frontonasal duct. ...


temporal bone: Squama temporalis (Articular tubercle | Suprameatal triangle | Mandibular fossa | Petrotympanic fissure) | Mastoid portion (Mastoid foramen | Mastoid process | Mastoid notch | Occipital groove | Sigmoid sulcus | Mastoid antrum) | Petrous portion (Hiatus of the facial canal | Internal auditory meatus | Subarcuate fossa | Carotid canal | Aqueduct of cochlea | Jugular fossa | Inferior tympanic canaliculus | Mastoid canaliculus | Styloid process | Stylomastoid foramen | Jugular foramen | Petrosquamous suture) | Tympanic part (Suprameatal spine) The temporal bones (os temporales) are situated at the sides and base of the skull. ... The anterior root of the posterior end of the outer surface of the Squama temporalis, continuous with the lower border, is short but broad and strong; it is directed medialward and ends in a rounded eminence, the articular tubercle (eminentia articularis). ... In the temporal bone, the mandibular fossa (glenoid fossa) is bounded, in front, by the articular tubercle; behind, by the tympanic part of the bone, which separates it from the external acoustic meatus; it is divided into two parts by a narrow slit, the petrotympanic fissure (Glaserian fissure). ... The mandibular fossa is bounded, in front, by the articular tubercle; behind, by the tympanic part of the bone, which separates it from the external acoustic meatus; it is divided into two parts by a narrow slit, the petrotympanic fissure (Glaserian fissure). ... It has been suggested that this article or section be merged with Mastoid process. ... The outer surface of the temporal bone is perforated by numerous foramina; one of these, of large size, situated near the posterior border, is termed the mastoid foramen; it transmits a vein to the transverse sinus and a small branch of the occipital artery to the dura mater. ... The mastoid process (or mastoid bone) is a conical bump of the posterior portion of the temporal bone that is situated behind the ear in humans and many other vertebrates and serves as a site of neck muscle attachment (the Sternocleidomastoid, Splenius capitis, and Longissimus capitis). ... On the medial side of the mastoid process is a deep groove, the mastoid notch (digastric fossa), for the attachment of the Digastricus. ... On the medial side of the mastoid process of the temporal bone is a deep groove, the mastoid notch (digastric fossa), for the attachment of the Digastricus; medial to this is a shallow furrow, the occipital groove, which lodges the occipital artery. ... Mastoid antrum (or tympanic antrum) is a cavity in the petrous portion of the temporal bone, communicating posteriorly with the mastoid cells and anteriorly with the epitympanic recess of the middle ear via the aperture of the mastoid antrum. ... A shallow groove, sometimes double, leading lateralward and backward to an oblique opening, the hiatus of the facial canal, for the passage of the greater superficial petrosal nerve and the petrosal branch of the middle meningeal artery. ... Near the center of the posterior surface of the temporal bone is a large orifice, the internal acoustic meatus (or internal auditory meatus), the size of which varies considerably; its margins are smooth and rounded, and it leads into a short canal, about 1 cm. ... On the interior surface of the temporal bone, behind the rough surface of the apex, is the large circular aperture of the carotid canal, which ascends at first vertically, and then, making a bend, runs horizontally forward and medialward; it transmits into the cranium the internal carotid artery, and the... 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... In the temporal bone, behind the openings for the carotid canal and the aquæductus cochleæ is a deep depression, the jugular fossa, of variable depth and size in different skulls; it lodges the bulb of the internal jugular vein. ... 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 of the temporal bone is the mastoid canaliculus for the entrance of the auricular branch of the vagus nerve. ... Between the styloid and mastoid processes is the stylomastoid foramen; it is the termination of the facial canal, and transmits the facial nerve and stylomastoid artery. ... Behind the carotid canal is the jugular foramen, a large aperture, formed in front by the petrous portion of the temporal, and behind by the occipital; it is generally larger on the right than on the left side, and may be subdivided into three compartments. ... The Petrosquamous suture is a cranial suture between the petrous portion and the squama of the temporal bone. ...


sphenoid bone: Sphenoidal sinuses | Ethmoidal spine | Optic foramen | Sella turcica | Fossa hypophyseos | Dorsum sellae | Posterior clinoid processes | Carotid groove | Lingula sphenoidalis | Sphenoidal conchæ | Great wings (Spina angularis | Foramen rotundum | Foramen ovale | Foramen Vesalii | Foramen spinosum | Infratemporal crest | Sulcus tubae auditivae | Small wings | Superior orbital fissure | Anterior clinoid process | Optic foramen) | Pterygoid processes (Pterygoid fossa | Scaphoid fossa | Lateral pterygoid plate | Medial pterygoid plate | Pterygoid hamulus | Sphenoidal conchæ | Sphenoidal sinuses) Figure 1 : Sphenoid bone, upper surface. ... The superior surface of the body of the sphenoid bone (Fig. ... The superior surface of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove), above and behind which lies the optic chiasma; the groove ends on either side in the optic foramen, which transmits the optic... The Sella turcica (literally Turkish saddle) is a saddle-shaped depression in the sphenoid bone at the base of the human skull. ... In the sphenoid bone, behind the chiasmatic groove is an elevation, the tuberculum sellæ; and still more posteriorly, a deep depression, the sella turcica, the deepest part of which lodges the hypophysis cerebri and is known as the fossa hypophyseos (or fossa hypophysialis). ... In the sphenoid bone, the anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the middle clinoid processes, while the posterior boundary is formed by a square-shaped plate of bone, the dorsum sellæ, ending at its superior angles in two tubercles... Above the attachment of each great wing of the sphenoid bone is a broad groove, curved something like the italic letter f; it lodges the internal carotid artery and the cavernous sinus, and is named the carotid groove. ... Along the posterior part of the lateral margin of the carotid groove of the sphenoid bone, in the angle between the body and great wing, is a ridge of bone, called the lingula. ... The great wings of the sphenoid, or ali-sphenoids, are two strong processes of bone, which arise from the sides of the body, and are curved upward, lateralward, and backward; the posterior part of each projects as a triangular process which fits into the angle between the squama and the... At th anterior and medial part of the Sphenoid is a circular aperture, the foramen rotundum, for the transmission of the maxillary nerve. ... At the base of the skull the foramen ovale is a hole that transmits the mandibular nerve, the otic ganglion, the accessory meningeal artery, emissary veins (from the cavernous sinus to the pterygoid plexus) and the lesser superficial petrosal nerve. ... In the base of the skull, in the great wings of the sphenoid bone, medial to the foramen ovale, a small aperture, the foramen Vesalii, may occasionally be seen (it is often absent) opposite the root of the pterygoid process. ... The foramen spinosum is the foramen in the skull that permits the passage of the middle meningeal artery. ... The lateral surface of the great wing is convex, and divided by a transverse ridge, the infratemporal crest, into two portions. ... The superior orbital fissure is a foramen in the skull, although strictly it is more of a cleft, lying between the lesser and greater wings of the sphenoid bone. ... In the sphenoid bone, the posterior border, smooth and rounded, is received into the lateral fissure of the brain; the medial end of this border forms the anterior clinoid process, which gives attachment to the tentorium cerebelli; it is sometimes joined to the middle clinoid process by a spicule of... The superior surface of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove), above and behind which lies the optic chiasma; the groove ends on either side in the optic foramen, which transmits the optic... The Pterygoid fossa, or the sphenoid bone is wedged between several other bones in the front of the cranium. ... The lateral pterygoid plate of the sphenoid (or lateral lamina of pterygoid process) is broad, thin, and everted; its lateral surface forms part of the medial wall of the infratemporal fossa, and gives attachment to the Pterygoideus externus; its medial surface forms part of the pterygoid fossa, and gives attachment... The medial pterygoid plate of the sphenoid is narrower and longer than the lateral pterygoid plate; it curves lateralward at its lower extremity into a hook-like process, the pterygoid hamulus, around which the tendon of the Tensor veli palatini glides. ...


ethmoid bone: Cribriform plate | Crista galli | Perpendicular plate | Labyrinth | Ethmoid sinus | Uncinate process | Middle nasal concha | Superior meatus | Superior nasal concha | Middle meatus 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. ... The ethmoid bone (os ethmoidale) is a bone in the skull that separates the nasal cavity from the brain. ... The crista galli (Latin: crest of the cock) is a median ridge of bone that projects from the cribriform plate of the ethmoid bone. ... Bones and cartilages of septum of nose. ... The Labyrinth or Lateral Mass of the ethmoid bone consists of a number of thin-walled cellular cavities, the ethmoidal cells, arranged in three groups, anterior, middle, and posterior, and interposed between two vertical plates of bone; the lateral plate forms part of the orbit, the medial, part of the... ethmoidal sinuses can be divided into 3: a) anterior b) middle c) posterior except the posterior ethmoidal sinus, all the ethmoidal sinuses will drain into middle meateus. ... An uncinate process is a hook shaped process on the lateral borders of the superior surface of the bodies of C3-C6 (T1). ... The medial surface of the labyrinth of ethmoid consists of a thin lamella, which descends from the under surface of the cribriform plate, and ends below in a free, convoluted margin, the middle nasal concha. ... The middle meatus is situated between the middle and inferior conchæ, and extends from the anterior to the posterior end of the latter. ...

Facial bones

maxilla: Incisive fossa | Maxillary sinus | Incisive fossa | Canine fossa | Infraorbital foramen | Anterior nasal spine | Alveolar canals | Orbitofrontal cortex | Infraorbital canal | Pterygopalatine canal | Zygomatic process | Agger nasi | Anterior lacrimal crest | Alveolar process | Incisive foramen | Incisive canals | Foramina of Scarpa | Premaxilla | Anterior nasal spine A hippopotamus skull A skull, or cranium, is a bony structure of Craniates which serves as the general framework for a head. ... The maxillae are the largest bones of the face, except for the mandible, and form, by their union, the whole of the upper jaw. ... On the anterior surface of the maxilla, just above the eminences corresponding to the incisor teeth is a depression, the incisive fossa, which gives origin to the Depressor alæ nasi; to the alveolar border below the fossa is attached a slip of the Orbicularis oris; above and a little lateral... The maxillary sinus is the largest paranasal sinus. ... On the anterior surface of the maxilla, just above the eminences corresponding to the incisor teeth is a depression, the incisive fossa, which gives origin to the Depressor alæ nasi; to the alveolar border below the fossa is attached a slip of the Orbicularis oris; above and a little lateral... Lateral to the incisive fossa is another depression, the canine fossa; it is larger and deeper than the incisive fossa, and is separated from it by a vertical ridge, the canine eminence, corresponding to the socket of the canine tooth; the canine fossa gives origin to the Caninus. ... Above the canine fossa is the infraorbital foramen, the end of the infraorbital canal; it transmits the infraorbital vessels and nerve. ... Medially, the anterior surface of the maxilla is limited by a deep concavity, the nasal notch, the margin of which gives attachment to the Dilatator naris posterior and ends below in a pointed process, which with its fellow of the opposite side forms the anterior nasal spine. ... The infratemporal surface of the maxilla is pierced about its center by the apertures of the alveolar canals, which transmit the posterior superior alveolar vessels and nerves. ... The orbitofrontal cortex is a region of association cortex the human brain involved in cognitive processes such as decision making. ... One of the canals of the orbital surface of the maxilla, the infraorbital canal, opens just below the margin of the orbit. ... The agger nasi is a small ridge on the lateral side of the nasal cavity. ... The lateral margin of the lacrimal fossa is named the anterior lacrimal crest, and is continuous below with the orbital margin; at its junction with the orbital surface is a small tubercle, the lacrimal tubercle, which serves as a guide to the position of the lacrimal sac. ... The alveolar process (processus alveolaris), also referred to as the alveolar bone, is the bone found in the jaws of a mouth containing the socket of teeth. ... When the two maxillæ are articulated, a funnel-shaped opening, the incisive foramen, is seen in the middle line, immediately behind the incisor teeth. ... In the opening of the incisive foramen, the orifices of two lateral canals are visible; they are named the incisive canals or foramina of Stenson; through each of them passes the terminal branch of the descending palatine artery and the nasopalatine nerve. ... In the maxilla, occasionally two additional canals are present in the middle line of the palatine process; they are termed the foramina of Scarpa, and when present transmit the nasopalatine nerves, the left passing through the anterior, and the right through the posterior canal. ... The premaxilla is a pair of small bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. ... Medially, the anterior surface of the maxilla is limited by a deep concavity, the nasal notch, the margin of which gives attachment to the Dilatator naris posterior and ends below in a pointed process, which with its fellow of the opposite side forms the anterior nasal spine. ...


lacrimal bone: Posterior lacrimal crest 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 . ...


zygomatic bone: Zygomaticofacial foramen | Zygomaticotemporal foramen | Zygomaticoörbital foramina The zygomatic bone (also known as the zygoma; Os Zygomaticum; Malar Bone) is a paired bone of the human skull. ...


palatine bone: Pterygopalatine fossa | Pterygoid fossa | Horizontal plate | Posterior nasal spine | Perpendicular plate | Pterygopalatine canal | Sphenopalatine foramen | Pyramidal process | Orbital process | Sphenoidal process 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. ... In the skull, the pterygopalatine fossa is the space between the lateral pterygoid plate (which is part of the sphenoid bone), and the palate. ... The Pterygoid fossa, or the sphenoid bone is wedged between several other bones in the front of the cranium. ... The horizontal part of the palatine bone (horizontal plate) is quadrilateral, and has two surfaces and four borders. ... The vertical part (perpendicular plate) of the palatine bone is thin, of an oblong form, and presents two surfaces and four borders. ... The orbital process of the palatine bone is placed on a higher level than the sphenoidal, and is directed upward and lateralward from the front of the vertical part, to which it is connected by a constricted neck. ...


mandible: Symphysis menti | Mental foramen | Mylohyoid line | Ramus mandibulae | Mandibular foramen | Mandibular canal The mandible (inferior maxillary bone) (together with the maxilla) is the largest and strongest bone of the face. ... The external surface of the mandible is marked in the median line by a faint ridge, indicating the Symphysis menti or line of junction of the two pieces of which the bone is composed at an early period of life. ... The mental foramen is a foramen in the mandible. ... Extending upward and backward on either side from the lower part of the symphysis of the Mandible is the mylohyoid line, which gives origin to the Mylohyoideus; the posterior part of this line, near the alveolar margin, gives attachment to a small part of the Constrictor pharyngis superior, and to... The Mandibular Foramen is an opening on the internal surface of the ramus for the mandibular vessels and nerve to pass. ... The mandibular canal runs obliquely downward and forward in the ramus, and then horizontally forward in the body, where it is placed under the alveoli and communicates with them by small openings. ...


others: nasal bone | inferior nasal conchae | vomer bone 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. ... It has been suggested that this article or section be merged with Nasal concha. ... The vomer bone is one of the unpaired facial bones of the skull. ...

composite structures

Cranial sutures: Coronal | Lambdoidal | Occipitomastoid | Parietomastoid | Sphenofrontal | Sphenoparietal |Sphenosquamosal | Sphenozygomatic |Squamosal | Zygomaticotemporal | Zygomaticofrontal | Frontal/Metopic | Sagittal | Frontoethmoidal | Petrosquamous | Sphenoethmoidal | Sphenopetrosal Side view of the skull. ... The coronal suture (sutura coronalis) is a dense, fibrous connective tissue joint that separates the frontal and parietal bones of the skull. ... The lambdoid suture (or Lambdoidal suture) is a dense, fibrous connective tissue joint that separates the parietal and temporal bones of the skull from the occipital bone. ... The occipitomastoid suture is the cranial suture between the occipital bone and the mastoid portion of the temporal bone. ... The squamosal suture arches backward from the pterion and connects the temporal squama with the lower border of the parietal: this suture is continuous behind with the short, nearly horizontal parietomastoid suture, which unites the mastoid process of the temporal with the region of the mastoid angle of the parietal. ... The squamosal suture arches backward from the pterion and connects the temporal squama with the lower border of the parietal: this suture is continuous behind with the short, nearly horizontal parietomastoid suture, which unites the mastoid process of the temporal with the region of the mastoid angle of the parietal. ... The frontal suture (sutura frontalis) is a dense connective tissue structure that divides the two halves of the frontal bone of the skull in infants and children. ... The frontal suture is a dense connective tissue structure that divides the two halves of the frontal bone of the skull in infants and children. ... The sagittal suture (sutura sagittalis) is a dense, fibrous connective tissue joint between the two parietal bones of the skull. ... The frontoethmoidal suture is the suture between the ethmoid bone and the frontal bone. ... The Petrosquamous suture is a cranial suture between the petrous portion and the squama of the temporal bone. ...


Asterion | Nasion | Pterion | Dacryon | Inferior orbital fissure For other uses, see Asterion (disambiguation) In human anatomy, the asterion is a visible, so-called craniometric, point on the exposed skull, just behind the ear, where three cranial sutures meet: the lambdoid, parieto-mastoid, and occipito-mastoid sutures. ... The nasion (nay-zhun) is the intersection of the frontal and two nasal bones of the human skull. ... The point corresponding with the posterior end of the sphenoparietal suture is named the pterion; it is situated about 3 cm. ... The point of junction of the maxillary bone, lacrimal bone, and frontal bone is named the dacryon. ... The lateral wall and the floor of the orbit are separated posteriorly by the inferior orbital fissure which transmits the maxillary nerve and its zygomatic branch, the infraorbital vessels, and the ascending branches from the sphenopalatine ganglion. ...


 
 

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