Cranial cavity

Musculoskeletal Effects. Rats administered up to 140 mg 4-nitrophenol/kg/day by gavage in water for 13 weeks showed no gross or histological alterations in the sternum (Hazleton 1989). In addition, no gross alterations were observed in the cranial cavity. 

A related study on human infants was performed by J. S. Wyatt et al. [36]. They used NIR to quantify the cerebral blood volume in human infants using NIR spectroscopy. Similar difficulties were encountered with the amount of light actually penetrating the cranial cavity, but useful equations were generated. 

The MOB in rodents is situated at the rostral pole of the cranial cavity and it is connected to the frontal... 

Sinonasal undifferentiated carcinoma (SNUG) is an aggressive tumor that is two to three times more common in men and occurs over a broad age range (average 55 to 60 years). The tumor commonly arises primarily in the nasal cavity but also can originate from the sinuses. Widespread invasion of the nasal cavity and paranasal sinuses is often present at the time of presentation. The tumor may also invade into the adjacent structures including the orbit or even into the cranial cavity. 

Small cell neuroendocrine carcinomas similar to those seen in the lung are exceptionally rare in the nasal cavity and paranasal sinuses. They affect both sexes equally and occur over a broad age range (38 to 68 years in one studyThey may arise either in the nasal cavity or in the paranasal sinuses, especially the ethmoid and maxilla. Though some tumors will remain localized to the site of origin, higher grade tumors are likely to invade into adjacent structures such as the orbit, cribriform plate, or cranial cavity. 

Meningiomas occurring outside the cranial cavity (ectopic or extracranial meningiomas) are uncommon. When they do occur, they are usually in the middle ear-mastoid and sinonasal tract-nasopharynx. When found, a primary intracranial meningioma with secondary involvement of the head and neck should be excluded. 

In the second frame of the cartoon, a brain surgeon uses a small circular saw to create an opening, a thin crack, all along the circumference of the man s head. The patient is pale and motionless. The doctor hands the medical saw to an assistant, opens the patient s cranial cavity by removing the skull cap, and then places this upper hemisphere of the skull in a bath of warm saline solution. 

Homo erectus Many remains of this type have been found around the world. Pithecanthropus (Java man) and Sinanthropus (Peking man) both fall into this category. Homo erectus specimens are smaller than the average human today, with an appropriately smaller head and cranial cavity where the brain fits. However, the brain size is within the range of modern humans. Studies of the middie ear have shown that Homo erectus was just iike us. Remains have been found in the same strata and in close proximity to ordinary Homo sapiens (modern man), suggesting that they lived together. Studies have shown that brain size fluctuations within Homo sapiens seem to have no correlation to intellectuality, so Homo erectus would not have been the dumb, brute caveman that has been implied in the past. 

The brain resides within the cranial cavity. The bony roof and sides of the cranial vault make up the calvaria, which is composed of frontal, temporal and parietal bones and a small portion of the occipital bone. The floor of the cranial vault is divided into three depressions or fossae the anterior fossa extends from the region superior to the orbits and nasal cavity caudaUy as far as the posterior margin of the lesser wing of the sphenoid the middle fossa occupies the region between the lesser wing of the sphenoid and the anterior border of the petrous portion of the temporal bone and the posterior fossa, is underlain by the remainder of the temporal bones and the occipital bone. 

The divisions of the cranial central nervous system include the cerebral hemispheres, the diencephalon (thalamus and hypothalamus), the brainstem (midbrain, pons and medulla oblongata) and the cerebellum (Fig. 1.2). Each cerebral hemisphere occupies one half of the cranial vault and can be subdivided into four lobes (frontal, parietal, temporal, occipital), the insula and the limbic lobe. The first four lobes are named for the cranial bones that overlie them. With respect to the floor of the cranial cavity, the frontal lobes lie in the anterior cranial fossa the brainstem and cerebellum occupy the posterior cranial fossa the remaining structures are found either in the middle fossa or within the portion of the cranial vault above the tentorium cerebelli. The insula is covered by the temporal lobe and is not observable unless the temporal lobe is retracted. The hmbic system is a continuous interior... 

The orbit is defined as the anatomic space in the skull that contains the eyeball and its accessory organs. At the orbital apex, many nerves and blood vessels pass from the orbit into the cranial cavity and vice versa. The orbit is pyramidal in shape, with four bony walls narrowing posteriorly toward the apex. 

The wax found in the cranial cavity of the marine mammal the sperm whale Physeter macrocephalus, syn. P. catodon) and two related species (pygmy sperm whale and dwarf sperm whale) from the sperm whale superfamily has industrial importance. The milky-white waxy substance, or spermaceti, is composed mainly of cetyl palmitate (3-42). The proportion of spermaceti with a lower melting point, containing predominantly unsaturated fatty alcohols, is called sperm oh. 

The brain, located in the cranial cavity, is made up of three main parts cerebrum, cerebellum, and brainstem. The cerebrum is the largest part of the human mature brain, which comprises left and right cerebral hemispheres with the corpus callosum between them. The outermost surface of the cerebral hemispheres is a 2-4 mm thick folded layer, named the cerebral cortex that is also called grey matter as it consists of neuronal cell bodies, glial cells, and capillaries showing dark in colour. By contrast, the underlying tissue in the cerebrum is called white matter which consists of the white myelinated sheaths of neuronal axons. 

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