![]() ![]() When looking into the nasal cavity from the front of the skull, two bony plates are seen projecting from each lateral wall. Each side of the nasal cavity is triangular in shape, with a broad inferior space that narrows superiorly. ![]() The upper portion of the nasal septum is formed by the perpendicular plate of the ethmoid bone and the lower portion is the vomer bone. Inside the nasal area of the skull, the nasal cavity is divided into halves by the nasal septum. An anterior view of the skull shows the bones that form the forehead, orbits (eye sockets), nasal cavity, nasal septum, and upper and lower jaws. Below the orbit is the infraorbital foramen, which is the point of emergence for a sensory nerve that supplies the anterior face below the orbit.įigure 2. This provides for passage of a sensory nerve to the skin of the forehead. Located near the midpoint of the supraorbital margin is a small opening called the supraorbital foramen. The upper margin of the anterior orbit is the supraorbital margin. The orbit is the bony socket that houses the eyeball and muscles that move the eyeball or open the upper eyelid. Also seen are the upper and lower jaws, with their respective teeth ( Figure 2). This view of the skull is dominated by the openings of the orbits and the nasal cavity. The anterior skull consists of the facial bones and provides the bony support for the eyes and structures of the face. Which bone (yellow) is centrally located and joins with most of the other bones of the skull? Anterior View of Skull Watch this video to view a rotating and exploded skull, with color-coded bones. The 22nd bone is the mandible (lower jaw), which is the only moveable bone of the skull. In the adult, the skull consists of 22 individual bones, 21 of which are immobile and united into a single unit. ![]() The rounded brain case surrounds and protects the brain and houses the middle and inner ear structures. The facial bones underlie the facial structures, form the nasal cavity, enclose the eyeballs, and support the teeth of the upper and lower jaws. It is subdivided into the facial bones and the brain case, or cranial vault ( Figure 1). The cranium (skull) is the skeletal structure of the head that supports the face and protects the brain. Identify the bony openings of the skull.Identify the bones and structures that form the nasal septum and nasal conchae, and locate the hyoid bone.Name the bones that make up the walls of the orbit and identify the openings associated with the orbit.Define the paranasal sinuses and identify the location of each.Locate and define the boundaries of the anterior, middle, and posterior cranial fossae, the temporal fossa, and infratemporal fossa.Locate the major suture lines of the skull and name the bones associated with each.List and identify the bones of the brain case and face.The upper-frontmost part of the cranium also houses the evolutionarily newest part of the mammal brain, the frontal lobes.By the end of this section, you will be able to: The neurocranium is formed by the endocranium, the lower portions of the cranial vault, and the skull roof.Įvolutionarily, the human neurocranium has expanded from comprising the back part of the mammalian skull to being also the upper part: during the evolutionary expansion of the brain, the neurocranium has overgrown the splanchnocranium. In Chondrichthyes and other cartilaginous vertebrates this portion of the cranium does not ossify it is not replaced via endochondral ossification. There is also some contribution of ectomesenchyme. The neurocranium arises from paraxial mesoderm. The roof may contain ridges such as the temporal crests. The size of the neurocranium is variable among mammals. The auditory bullae, located in the same region, aid in hearing. There may variably also be extra sutural bones present.īelow the neurocranium is a complex of openings ( foramina) and bones, including the foramen magnum which houses the neural spine. The ossicles (three on each side) are usually not included as bones of the neurocranium. In humans, the neurocranium is usually considered to include the following eight bones: the cartilaginous part, or chondrocranium, which forms bones of the base of the skull.the membranous part, consisting of flat bones, which surround the brain and.The neurocranium is divided into two portions: In comparative anatomy, neurocranium is sometimes used synonymously with endocranium or chondrocranium. The remainder of the skull is the facial skeleton. In the human skull, the neurocranium includes the calvaria or skullcap. In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan is the upper and back part of the skull, which forms a protective case around the brain. ![]()
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