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Designing for Head and Neck Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
The interior of the skull is more detailed and intricate then just one hollow space. The skull has several hollow areas, each with a specific function. Major superficial skull cavities are the eye sockets or orbits, ear canals, oral (mouth) cavity, and nasal (nose) cavity. The inside of the cranium is shaped around these cavities. The largest internal hollow area, the cranial cavity, acts as a container that holds the brain along with the CSF. The sinuses are hollow cavities near the respiratory passages and the cranial cavity. The spinal cord passes through a large opening at the base of the skull, the foramen magnum. These details are also seen in Figure 3.2. Additional small openings or passages throughout the skull provide spaces for nerves and blood vessels as they connect from inside the head to the superficial structures of the head.
A new early Miocene archaic dolphin (Odontoceti, Cetacea) from New Zealand, and brain evolution of the Odontoceti
Published in New Zealand Journal of Geology and Geophysics, 2023
Yoshihiro Tanaka, Megan Ortega, R. Ewan Fordyce
The natural endocast is formed by matrix and shell fragments (Figure 5) that replicate the outer morphology of the brain (e.g. Breathnach 1955; Oelschläger and Oelschläger 2009). It is anteriorly narrowly triangular in dorsal view (150 mm long from the anterior tip to dorsal margin of the foramen magnum, 165 mm wide, 88 mm high), and there are no signs of gyri on the endocast surface (furthermore, such traces are rarely preserved in extant odontocete endocasts; see Breathnach (1955)). Its ventral side was eroded by waves. The cerebellum is located posterior to the cerebrum, just inside of the dorsal condyloid fossa. The cerebellum swells weakly posterolaterally (Figure 5B–D). The cerebrum is posteriorly wide at the level of the temporal lobe. A shallow sylvian fissure runs dorsal to anterior margins of the temporal lobe. From the foramen magnum, the cerebrum rises gradually to the border between the squamosal and parietal of the nuchal crest. The posterior surface of the cerebrum is flat. From the highest point of the cerebrum to the temporal lobe is a ridge, which probably marks the middle meningeal artery following the squamosal/parietal border. Anterior to the middle meningeal artery, there is a restriction making the cerebrum dramatically narrow anteriorly. The olfactory fossa (see discussion) projects anteriorly from the anterior end of the cerebrum. The olfactory fossa is huge, in spite of the left side being broken (reconstructed width is about 29 mm). Its ventral side is eroded, but the preserved base shows it was high (maximum height is 44 mm) and narrow. Estimated volume of the cranial cavity is around 1000 milliliters, based on the volume of the endocast with some skull fragments as 1359 milliliter using volume displacement.