Cerebral hemispheres

Urbach H, Flacke S, Keller E, Textor J, Berlis A, Hartmann A, Reul J, Solymosi L, Schild HH. Detectability and detection rate of acute cerebral hemisphere infarcts on CT and diffusion-weighted MRI. Neuroradiology 2000 42 722-727. 

In the emergency situation, we beheve this technique can be successfully employed in selected patients with symptomatic ischemia due to dissection or atherosclerotic disease despite being on maximal medical therapy. We have also seen patients with carotid occlusion and an isolated cerebral hemisphere (poor collateral flow) benefit from EC-IC bypass. Any potential benefit, however, must... 

Head CT shows a multilobar infarction/hypodensity involving more than one-third of the cerebral hemisphere (not an absolute contraindication)... 

Brain metastasis is the most common neurologic complication seen in patients with cancer. Approximately 170,000 patients develop brain metastases in the United States each year.20 Many malignancies are frequently associated with brain metastases (Table 96-7). While melanoma is the tumor type most likely to metastasize to the brain, brain metastases owing to lung and breast cancers are seen more often because they are among the most common cancers. In addition, brain metastasis may be diagnosed at the same time as the primary malignancy in around 20% of cases.22 Around 80% of brain metastases occur in the cerebral hemispheres, 15% in the cerebellum, and 5% in the brain stem. 

Gn Pig (NS) 11 d 1 hr/d 20 M (decreased cerebral hemisphere and brain stem total lipids and phospholipids) ... 

Figure 6.2 Frontal section of the brain. The cerebrum is composed of two types of tissue internal white matter and external gray matter which forms the cerebral cortex. Embedded within the cerebral hemispheres are other masses of gray matter, basal ganglia, and thalamus. The ventricles are filled with cerebrospinal fluid (CSF).

These ascending sensory pathways cross from one side of the CNS to the other so that sensory input from the left side of the body is transmitted to the somatosensory cortex of the right cerebral hemisphere and visa versa. Therefore, damage to this region of cortex in a given hemisphere results in... 

Embedded within the brain are four ventricles or chambers that form a continuous fluid-filled system. In the roof of each of these ventricles is a network of capillaries referred to as the choroid plexus. It is from the choroid plexuses of the two lateral ventricles (one in each cerebral hemisphere) that cerebrospinal fluid (CSF) is primarily derived. Due to the presence of the blood-brain barrier, the selective transport processes of the choroid plexus determine the composition of the CSF. Therefore, the composition of the CSF is markedly different from the composition of the plasma. However, the CSF is in equilibrium with the interstitial fluid of the brain and contributes to the maintenance of a consistent chemical environment for neurons, which serves to optimize their function. 

Textbooks on neuroscience often describe the location and function of hundreds of individual brain regions (see references above). However, for current purposes these will be kept to a minimum (Figure 2.1). Anatomically, the brain can be subdivided into the forebrain containing the telencephalon and diencephalon, the midbrain or mesencephalon and the hindbrain (metencephalon and myelencephalon). The telencephalon includes the left and right cerebral hemispheres encompassed by the cerebral cortex (neocortex). Cortex is a translation of the word bark and is so-called because its surface, made up of numerous sulci (grooves or invaginations) and gyri (raised areas), is on the outer surface of the brain like the bark of a tree. Each hemisphere is divided into four lobes, named from the front (rostral) to back (caudal) of the brain frontal, temporal, parietal and occipital. 

Cerebral cortex Together with the two underlying cerebral hemispheres is the largest part of the brain. 

Corpus callosum A bridge of nerve fibres between the two cerebral hemispheres. 

Neocortex The cerebral cortex overlying the cerebral hemispheres. 

Occipital lobe One of four, together with the frontal, parietal and temporal, lobes of the cerebral hemispheres. 

BBB-RNA must be isolated for molecular cloning and analysis of BBB-specific transcripts, and several methods for isolating BBB-poly (A+) mRNA in one or more steps have been described [68]). Li et al. recently reported that they obtained yields of 12 pg poly (A+) mRNA from a single bovine cortical shell and 3.2 pg poly (A+) mRNA from the pooled cerebral hemispheres of 21 rats [70]. 

Left cerebral hemisphere ventral side up hippo hippocampus... 

FIGURE 1-1 Coronal section of the human brain at the thalamic level stained by the Heidenhain technique for myelin. Gray matter stains faintly, all myelinated regions are black. The thalamus ( ) lies beneath the lateral ventricles and is separated at this level by the beginning of the third ventricle. The roof of the lateral ventricles is formed by the corpus callosum (small arrows). Ammon s horns are shown by the large arrows. Note the outline of gyri and sulci at the surface of the cerebral hemispheres, sectioned here near the junction of the frontal and parietal cortices. 

Corpus caiiosum a brain structure consisting of axons connecting the two cerebral hemispheres. 

Figure 1.2 presents a coronal section through the human brain. In brief, the brain may be divided into the brainstem (consisting of the medulla, pons and midbrain) that is linked to the diencephalon which is composed of the thalamus and the hypothalamus. The two cerebral hemispheres are linked by the corpus callosum, a large tract of nerve fibres that enables the two... 

Examine the head, upper and lower jaws and lips, snout, naris, diagrams and relevant descriptions correspond. Nasolabial sul-cus/cleft, nasal cavity and septum, oral cavity, palate, palatine ridges, incisors, cranium, pinna, eyelid, eye/lens, retina, cornea, vitreous and aqueous chambers, nasopharynx, olfactory lobe, cerebral hemispheres, lateral ventricles, cranial nerves, third ventricle, pituitary, pineal gland, thalamus, perimeningeal space, and internal ear. 

Interventricular foramen Right cerebral hemisphere Pituitary gland... 

Right cerebral hemisphere External auditory canal Right cranial nerve V... 

Lett lateral ventricle Subdural space Left cerebral hemisphere... 

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