Basic introduction Chinese name: Pinyin of parietal bone: dǐng gǔ/gū Attribute: Skull shape: slightly oblate, with features on the top of the head: one on the left and one on the right. Introduction: refer to the phonetic notation of skull: ㄉㄧㄥㄡㄨㄨミㄨㄨㄨㄨㄨㄨㄨㄨㄨㄨㄨㄨㄨㄨㄨ. Cranial trauma is very common here, sometimes it can be depressed or comminuted fracture. Anatomical structure of the skull The skull includes occipital bone, sphenoid bone, temporal bone, parietal bone, frontal bone and ethmoid bone. Occipital occipital bone is located in the posterior lower part of the skull, showing a gourd-shaped quadrilateral. There is a foramen magnum in the anterior lower part, occipital scales in the posterior upper part of the foramen, lateral parts on both sides of the foramen, and a base in front of the foramen. ① Occipital scale, whose center is the extraoccipital protuberance, extends to both sides to form the upper cervical line, and the protuberance with forward midline is the extraoccipital ridge. The inner surface is concave and divided into four nests by cross uplift. The upper two are triangles corresponding to the occipital lobe of the brain, and the lower two are squares adjacent to the cerebellum. The center of the carina is occipital carina, and there is an upper sagittal sinus groove upward, which passes through the carina and connects with the right transverse sinus groove. The internal ridge of occipital bone extends forward from carina to foramen magnum. ② In the lateral part, the occipital condyle is below and connected with the atlas, and the longitudinal axis of the occipital condyle points to the anterior medial side. There is sometimes a condylar canal in the posterior condylar fossa, which leads to the vein. There is a hypoglossal nerve tube above the anterior condyle, through which the hypoglossal nerve () passes. The lateral front edge is depressed, which is called jugular notch, and its lateral branch processes outward, becoming jugular process. The jugular notch and jugular process together with the temporal bone constitute the jugular foramen of the whole skull. ③ The basal part, facing forward and upward, and the lateral (lower) central protuberance, that is, the pharyngeal nodule, is attached by the pharyngeal suture; The inner surface is slightly concave, called clivus, which supports pons, medulla oblongata and basilar artery; On both sides is the inferior petrosal sinus groove. Sphenoid bone The sphenoid bone is butterfly-shaped, located between the skull base, occipital bone and temporal bone, and is divided into a central body, a large wing and a small wing extending to both sides, and a downward protruding pterygoid process (Figure 1). ① Body and sphenoid sinus are hollow. The upper part of the body is sunken into a sella turcica, starting from the anterior cruciate sulcus in front, followed by the transverse tubercle of the sella, and then the sunken place for accommodating the pituitary gland, so it is called the pituitary fossa, and the back of the fossa is the upward raised saddle back; Both sides of the saddle back protrude backward and outward, that is, the posterior clinoid process. The longitudinal groove at the junction of the body and the great wing, which passes through the internal carotid artery, is called carotid groove. The protrusion in the middle of the front of the body is the sphenoid ridge, and the downward protrusion under the body is called the sphenoid orifice. The anterior opening of sphenoid sinus was covered by sphenoid nail, leaving the sphenoid sinus opening. After adulthood (about 25 years old), the back of the body is connected with the base of the occipital bone. ② Winglet, the anterior and lateral branches of autograft protrude outward, the anterior part is connected with frontal bone and ethmoid bone, the posterior margin is free, and the medial end is anterior clinoid process; The fissure between pterygoid apex connects middle cranial fossa and orbit, which is called supraorbital fissure. The winglet starts from two feet, and the optic canal is between them. The connecting line passes through the lateral end of the anterior sulcus to reach the orbit, and passes through the optic nerve (II) and ophthalmic artery. ③ The large wing extends outward from the body and is embedded in the whole skull, forming the middle cranial fossa, the lateral orbital wall, the temporal fossa and the upper wall of the infratemporal fossa. The deep depression on the surface of the brain is adjacent to the temporal lobe of the brain. The round hole on the front and inner side leads horizontally forward to pterygopalatine fossa, through which maxillary nerve (V2) passes. The foramen ovale is large, located in the posterolateral part of the foramen ovale, below the infratemporal fossa and passing through the mandibular nerve (V3). The foramen near the sphenoid spine also leads to the infratemporal fossa, which is the entrance of the middle meningeal artery into the skull. The temporal surface of the great wing constitutes the base of the temporal fossa and is attached to the temporal muscle. Below the temporal fossa is the top of the infratemporal fossa. This surface and the temporal surface are bounded by the infratemporal crest. The orbital surface of the big wing is square, facing forward and inward, forming the orbital side wall. ④ The pterygoid process itself protrudes vertically downward at the junction with the great wing, forming the lateral wall of nasal cavity, the medial wall of infratemporal fossa and the posterior wall of pterygopalatine fossa. The pterygoid process is divided into medial and lateral plates by the posterior wing fossa. The rear edge of the inner lateral plate forms the lateral edge of the posterior nostril, and the lower end is provided with a wing hook. In front of pterygoid process root, pterygoid canal connects the rupture hole and pterygopalatine fossa, and pterygoid canal nerve passes through it. The sheath process is located at the junction of the medial plate and the body, and there are palatal sheath groove and plough sheath groove above and below the process respectively, forming a homonymous tube in the whole skull. Figure 1 sphenoid bone (top view) 1, sphenoid winglet 2, sphenoid winglet 3, pituitary fossa 4, saddle back 5, foramen spinosum 6, foramen ovale 7, foramen ovale 8, and supraorbital fissure temporal bone are located between sphenoid bone and occipital bone, which constitute a part of the bottom and side wall of cranial cavity, and also participate in the formation of temporal fossa and infratemporal fossa, and are divided into scales. The zygomatic process protrudes from the lower part of the face and points to the anterior zygomatic temporal process, forming the zygomatic arch. Its lower surface is connected with the deep recess of mandibular head, which is called mandibular fossa; The protuberance of the articular tubercle in front of the mandibular fossa is the front boundary of the mandibular fossa ② The tympanum is an incomplete annular bone below the scale and before the mastoid process, which lives below the external auditory canal; There is a tympanic groove at its inner end, which is the attachment of tympanic membrane. The external ear door is surrounded by drums from the front, bottom and back. ③ The petrous bone (cone) is hard, containing the inner ear and the tympanum, and its mastoid is on the posterolateral side. The inside of the mastoid process is the deep impression of the mastoid process, which is the attachment of the posterior abdomen of the digastric muscle. The occipital artery groove is on the inside, and the occipital artery passes through it. The sigmoid sinus groove can be seen on its inner surface. There is a small drum rope tube between the lower surface of the rock and the drum part, and the drum rope passes through it. The cone itself is in the shape of a triangular pyramid, extending forward and inward from the inner surface of the scale and drum, embedded between the sphenoid bone and the occipital bone, and divided into three surfaces: front, back and lower. The front end of the cone is the base of the middle cranial fossa, and the near tip is the location of the trigeminal ganglion, which is slightly depressed and becomes the impression of the trigeminal nerve. The mask has an arch bulge, a bulge, a small rock, a crack in the petrosal canal, a small petrosal nerve sulcus and a large petrosal nerve sulcus. The upper edge of the rock is between the front and the back, and there is a sinus on the rock. The posterior part belongs to the posterior cranial fossa, and the anterior part is the inner ear portal, which is the entrance and exit part of facial nerve (ⅶ) and vestibulocochlear nerve (ⅷ). The posterolateral fracture of the inner ear gate is the external orifice of vestibular aqueduct. The lower edge is between the back and the bottom, and the inferior petrosal sinus is in front. Near the center of the lower surface is the outer entrance of carotid canal, which leads to carotid canal. The pipeline passes through the inner mouth of carotid canal from the rock tip and opens at the back wall of the fracture hole. The posterior bony surface of carotid canal's external orifice is concave, and it is a jugular fossa, which is connected with the occipital jugular notch to form a jugular foramen, through which the inferior petrosal sinus, glossopharyngeal nerve (XI), vagus nerve (X), accessory nerve (XI) and sigmoid sinus pass from front to back. The posterior end of the osseous septum between the external orifice of carotid canal and jugular foramen is wide and contains an obvious fossa, namely the external orifice of cochlear duct. Stylomastoid foramen can be seen between styloid process and mastoid process, extending forward, downward and inward, which is the cranial tunnel of facial nerve (VII). The gap between the tip of the petrous part and the sphenoid body and occipital bone is called a rupture hole, and its lower mouth is often covered by cartilage in living body. Fig. 2 Exterior view of temporal bone (right side) 1, scale 2, mandibular fossa 3, zygomatic process 4, external auditory canal 5, petrous part 6, tympanic part 7, styloid process 8, mastoid parietal bone is quadrangular, convex and concave, and can be divided into two sides, four sides and four corners. Posterior lateral tubercle and apical foramen near sagittal margin can be seen, and there are superior and inferior temporal lines outside the midline. The inner surface has an upper sagittal sinus groove along the sagittal edge; The sigmoid sinus passes through the mastoid angle to form the sigmoid sinus groove. The frontal bone is divided into a shell-like frontal scale perpendicular to the front, a horizontal orbital part and a nose protruding from the front; It constitutes the anterior wall and bottom of the anterior cranial fossa and the top of the orbit. ① Frontal scales are divided into external, internal and temporal surfaces. Frontal tubercle with circular protrusions on both sides of the outer lower part is the site of primary ossification, which is more obvious in women and infants. Below is the eyebrow arch, which is more prominent in men; Between the inner ends of the eyebrow arches on both sides, it is called the brow. At the junction of medial 1/3 and lateral 2/3 of the superior orbital margin, there is a supraorbital foramen or notch, through which nerve and blood vessels of the same name pass. Further inward, the frontal notch or hole can be seen in half of the skull, and the branches of the nerve and blood vessels on the trochlear pass through. The lateral end of the superior orbital margin stops at the zygomatic process. The brain imprint, arterial groove and granule pit on the inner surface are obvious; On the median line, there are superior sagittal sinus, frontal crest and blind hole from top to bottom. The part of the temporal surface below the temporal line constitutes the anterior part of the base of the temporal fossa to which the temporal muscle is attached. (2) The nose, located between the upper edges of both sides of the orbit, gradually tapers downward to become a nasal spine. ③ The middle orbit is divided into left and right triangular orbital plates by ethmoid notch, which separates the anterior cranial fossa from the orbit. The superficial depression or spine inside the orbital surface is the attachment point of the superior oblique tendon pulley, which is called the trochlear spine or trochlear depression. The lateral branch is the location of the lacrimal gland, which is called the lacrimal fossa. Anterior ethmoid foramen and posterior ethmoid foramen (tube) are formed by the junction of frontal bone and sieve plate, which communicate the orbit with nasal cavity. Frontal sinus, one on the left and one on the right, the nasal septum is often biased to one side, so the left and right sinuses are different in size, opening from the frontal nasal tube to the middle nasal passage. The ethmoid bone is thin and brittle, located between the two orbits, in front of the sphenoid bone and behind the frontal bone, and constitutes the bottom of the anterior cranial fossa, the top wall of the nasal cavity, the lateral wall and the medial wall of the orbit. In the front view, the ethmoid bone is towel-shaped, which is divided into sieve plate, vertical plate and ethmoid bone labyrinth on both sides. ① Sieve plate, located in horizontal position, embedded in ethmoid notch of frontal bone, separating cranial cavity from nasal cavity, with more than 20 sieve holes, communicating with olfactory nerve root filament (I). Fig. 3 sieve bone A, top view B, front view 1, orbital plate 2, sieve plate 3, comb 4 and vertical plate comb protrude above the plate. ② Vertical plate, which divides the nasal cavity into left and right halves, forms the upper part of the bony nasal septum, which is connected with the cartilage of the nasal septum in front and the vomerous bone in the lower part. ③ ethmoidal labyrinth is the general name of ethmoidal sinus, which is divided into anterior, middle and posterior ethmoidal sinus by two frontal septa. The lateral wall of labyrinth is called orbital plate, which is made into the medial wall of orbit. The inner labyrinth is irregular, and the upper turbinate and middle turbinate curl downward and outward. The labyrinthine posterior, middle and anterior ethmoidal sinuses all lead to the nasal cavity.