The general form of the skul

The inner base of the skull (basis cranii interna) is the support for the base of the brain, thus has a characteristic topography. There are three cranial fossa.

Anterior cranial fossa is formed by parts of the orbital frontal bone, the small wings of the sphenoid and ethmoid plate of the ethmoid bone. It includes the frontal lobes of the cerebral hemispheres. Front and sides of anterior cranial fossa limits the frontal scales. Rear of the middle cranial fossa it divides the rear edge of the small wing of sphenoid bone.

Middle cranial fossa form a wedge, and the temporal bone. In its deepening are the temporal lobes of the cerebral hemispheres. In the pituitary fossa that lies in the central part of the middle cranial bones, is lower appendage of the brain - the pituitary gland. At the top of the pyramid of the temporal bone has torn a hole (foramen lacerum), and through the upper orbital slot and holes in the large wings of the sphenoid bone are blood vessels and nerves. Of the posterior cranial fossa is separated back middle of the sella turcica and the upper edge of the pyramid of the temporal bone.

Posterior cranial fossa for the most part forms the occipital bone. In addition, it involves the formation of a body of sphenoid bone, posterior surface of the pyramid of the temporal bone and parietal bone lowback angle. Through the foramen magnum cranial cavity is connected to the vertebral canal. Front of the large holes in the central regions of the posterior cranial fossa, is the brain stem. On each side of the large aperture located cerebellar hemisphere.

The outer base of the skull (basis cranii externa) is formed bone brain and facial skull. The front part of the outer face of the sky is called. It is the bone sky. Front and sides of the sky limit of the upper jaw teeth. Posteriorly from the sky are holes - choanae, through which the nasal cavity communicates with the pharynx. Lateral to the posterior nares are pterygoid processes of sphenoid bone. Another lie lateral to the lower surface of the different formations of the pyramid of the temporal bone and greater wing of sphenoid bone, such as mandibular fossa, the external opening of carotid canal stylomastoid opening subulate appendage, etc.

Posterior parts of the outer base of the skull forms the occipital bone. Most of the occipital surface of the scales used for attachment of muscles.

Orbit (orbita) is a steam chamber, four-sided pyramid-shaped, the apex of which is directed posteriorly and medially. Bottom entry into the orbit limits infraorbital region of the upper jaw and cheekbone, above - supraorbital margin of frontal bone, with the lateral side - zygomatic bone and zygomatic process of frontal bone and the medial - frontal bone and frontal process of the maxilla.

The upper wall of the orbit form a small wing of sphenoid bone and orbital part of frontal bone. Bottom wall is almost entirely the orbital surface of the upper jaw. In the formation of the front of the zygomatic bone is involved, but closer to the top - orbital process of palatine bone. The lateral wall consists of the zygoma and orbital surface of greater wing of sphenoid bone. The upper sections of the medial wall of the orbital frontal bone and anterior to posterior medial wall is formed by frontal process of the maxilla, lacrimal bone, orbital plate of ethmoid and sphenoid body. In the anterior medial wall of lacrimal sac fossa is located.

At the top of the pyramid there is a hole orbital optic canal, through which the optic nerve. Verhnebokovoy front corner of the pyramid contains the lacrimal fossa, behind it is the upper orbital slot, through which orbit communicates with the cranial cavity. Most of the inferolateral corner is the lower orbital slot through which the orbit communicates with the infratemporal and pterygopalatine pits.

Nasal cavity (cavitas nasi) located in the center of the facial skull. Below it is limited to the oral cavity from the top - the cranial cavity. On each side of the nasal cavity is bordered by the eye sockets and the maxillary sinuses. It is isolated front and rear openings, top, bottom and two side walls, as well as bone septum.

The front opening, which is also called pear-shaped, form the nasal bones and nasal notch of the upper jaw. The rear holes are called Joan, and serve to communicate with the nasal pharynx. Bottom horizontal plate choanae limited palatine bone, from above - the body of sphenoid bone, from the sides - the medial plate of pterygoid process. From each other choanae separated bone septum, which is formed by vomer and perpendicular plate of ethmoid bone.

The lower wall of the nasal cavity is a bony sky, which includes a horizontal plate of palatine bone and palatine process of the maxilla. The upper wall of the nasal cavity consists of the nasal bones, ethmoid plate of the ethmoid bone, sphenoid body and the bow of the frontal bone. The side wall of the nasal cavity is formed by the nasal and lacrimal bones, mandible, inferior turbinate, ethmoid labyrinth, perpendicular plate of palatine bone, the medial plate of pterygoid process of sphenoid bone.

Depart from the sidewall of the three turbinates, dividing the lateral sections of the nasal cavity and nasal passages. The upper and middle basin are part of the ethmoidal labyrinth. In the lower nasal passage formed by the bottom of the mouth and the inferior turbinate, nasolacrimal duct opens. In the middle nasal duct, formed by the lower and middle turbinates, opens the maxillary and frontal sinuses, the anterior and middle ethmoidal labyrinth cells. In the upper nasal passage, which lies between the middle and upper turbinates, opens sinus sphenoid and posterior ethmoidal labyrinth cells.

Oral cavity (cavitas oris) in the front and sides of the limiting teeth, alveolar processes of the maxilla and the alveolar part of mandible, and on top - bone sky. On bone sky is the cutting hole through which the mouth communicates with the nasal cavity. In the back of the palate there is a large hole through which blood vessels and nerves.

Temporal fossa (fossa temporalis) form the parietal bone, frontal scales, the large wings of sphenoid bone and squamous part of temporal bone. It is temporalis muscle. Temporal fossa in front limits the zygomatic bone, above and behind - the superior temporal line, and bottom - the zygomatic arch.

Infratemporal fossa (fossa infratemporalis) contains the muscles. In front of its limited infratemporal surface of the upper jaw and cheekbone, top - the big wing of sphenoid bone, with the lateral side - a branch of the mandible and the medial - pterygoid bone sphenoid bone. With the infratemporal fossa infraorbital slot communicates with the eye socket.

Winglike-palatine fossa (fossa pterygopalatina) is a continuation of infratemporal fossa and is located over the hill of the mandible. Behind its limits pterygoid bone sphenoid bone, medial - perpendicular plate of palatine bone. Winglike-palatine fossa communicates with the cranial cavity, nasal cavity, mouth, eye socket and the ragged hole area.





List of Abbreviations

a., aa. — arteria, arteriae (artery, the artery)

lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)

m., mm. — musculus, musculi (muscle, the muscle)

n., nn. — nervus, nervi (nerve, the nerve)

r., rr. — ramus, rami (branch)

s. — seu (or)

v., vv. — vena, venae (vienna)