Cerebral vasculature

Neuritic plaques are lesions found in brain and cerebral vasculature. 

It is clinically significant that cerebral blood flow increases as a result of a direct relaxant action of halothane on cerebral vasculature. Intracranial pressure may rise to a level at which it can become dangerous in patients with intracranial pathology. Although the coronary arteries are dilated, coronary blood flow decreases because of the overall reduction in systemic blood pressure. Thus, the balance between myocardial perfusion and oxygen demand (which is reduced with halothane) should be taken into account for patients with cardiac disease. 

In particular, conditions of Aft overproduction or impaired cerebral Aft clearance mechanisms result in elevated Aft levels that promote Aft aggregation, oligomerization, and fibrillogenesis [20]. Deposition of Aft in an insoluble beta-pleated conformation (amyloid) occurs as plaques in the neuropil and as amyloid angiopathy in the cerebral vasculature. The deposition of amyloid initiates a cascade of injurious events, including free radical production, glial activation, and direct neuronal damage. Kinase activation in response to amyloid-induced injury may increase the amount... 

Correct choice = A. Morphine causes increased cerebrospinal fluid pressure secondary to dilation of cerebral vasculature. Methadone can relieve withdrawal symptoms because opioids show cross sensitivity. It is administered parenterally because absorption from the gastrointestinal tract is unreliable. 

The consequences of the hypertensive interaction are variable. Many individuals remain unaware of relatively minor increases in blood pressure. However, if the rise is large and rapid (an increase of 30 mmHg or more in systolic pressure within 20 minutes), the patient experiences a sudden severe occipital headache and palpitation, which may be associated in rare instances with subarachnoid hemorrhage or cardiac failure, if the cerebral vasculature or cardiac musculature are already weakened. 

There are a large number of rare arterial disorders or anomalies that can cause ischemic stroke (Tables 3.2 and 6.1). The frequency of many of these disorders has probably been underestimated because of under-investigation and lack of radiological imaging of the cerebral vasculature beyond the carotid bifurcation. 

Kidwell CS, Hsia AW (2006). Imaging of the brain and cerebral vasculature in patients with suspected stroke advantages and disadvantages of CT and MRI. Current Neurology and Neuroscience Reports 6 9-16... 

Neuritic plaques are lesions found in brain and cerebral vasculature. Whether genetic variations promote a primary amyloidosis in the majority of AD patients is unresolved. 

The adherent junctions are ubiquitously found in the cerebral vasculature and mediate several functions, including the adhesion of endothelial cells to each other, contact inhibition during remodeling, and growth of the vasculature, and mediate in part the regulation of paracellular permeability (Hawkins and Davis, 2005). The most important components of the adherent junctions are vascular endothelial... 

The cerebral vasculature can also be vulnerable to ergot-induced vasoconstriction. 

Whereas the suspected mechanism for ischemic stroke is analogous to that leading to myocardial infarction (hypoperfusion distal to a critical lesion), intracerebral bleeding (14,15) may be more difficult to explain. The authors considered the likelihood of sildenafil-induced spontaneous intracerebral hemorrhage due to the vasodilatory effects of the drug on the cerebral vasculature (as evidenced by headache, flushing, and nasal congestion). 

Harris RJ, Branston NM, Symon L, Bayhan M, Watson A The effects of a calcium antagonist, nimodipine, upon physiological responses of the cerebral vasculature and its possible influence upon focal cerebral ischaemia. Stroke 13 759-766,1982... 

Fabry, Z. and Hart, M. N., Antigen presentation at the cerebral vasculature, in The Blood-Brain Barrier, Pardridge, W. M., Ed., Raven Press, New York, 1993, chap. 3. 

Luthert, P.J. Greenwood, J. Pratt, O.E. Lantos, P.L. The Effect of Metabolic Inhibitor upon the Properties of the Cerebral Vasculature During Whole-Head Saline Perfusion of the Rat, Quart. J. Exp. Physiol. 72, 129-141 (1987). 

Transgenic mice overexpressing EC-SOD have better neurological outcome and cognitive performance after severe cranial impact [171]. Such animals were, however, more susceptible to hyperbaric oxygen than control animals, an effect ascribed to sparing excessive levels of nitric oxide and thus blocking the normal vasoconstrictive response of the cerebral vasculature to hyperoxia [ 172]. 

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