Efferent Branches Research Articles

Experimental observations concerning cerebral angiography.

AN UNUSUAL opportunity for studying the intracranial and extracranial circulations simultaneously was afforded by a perfusion method of angiography in the cat, using the vertex-base x-ray projection. By this technique the entire circle of Willis, as well as its main afferent and efferent branches, could be visualized roentgenographically together with much of the extracranial carotid system. It was thus possible to make certain observations of general interest concerning the cerebral circulation and of particular interest in regard to some etiologic factors concerned with neurologic sequelae of carotid angiography. The technique of photomicrography was also utilized in order to include pial arteries in this study. METHODS Carotid Angiography. —A total of 220 angiographic studies were performed on 14 cats, with 10% colloidal suspension of thorium dioxide (Thorotrast) used as the contrast medium in all but 2 experiments, in which 35% iodopyracet (Diodrast) was employed. The common carotid artery was cannulated with

Site of Hypersensitiveness of the Exaggerated Sinus Caroticus Reflex

Before Hering's1 discovery of the carotid sinus reflex, the slowing of the pulse which results from pressure over the upper area of the carotid artery, particularly on the right side of the neck, was interpreted as the direct effect of pressure upon the vagus nerve. Variations in the effect on heart rhythm were considered as indicative of the condition of the heart muscle and the Wenckebach2 school particularly attempted to use such differences in the prognostication of heart disease. Weil:1 agreed with Wenckebach that a prolonged cardiac arrest was due to a hypersensitiveness of the vagus endings in the myocardium consequent on pathological changes in the heart. Hering, having discovered that a reflex mechanism and not a direct stimulation is at play, became interested in the receptor organs of the afferent branch of the arc rather than in the end organs of the different efferent branches. He considered that a marked slowing of the pulse on pressure over the sinus caroticus was due to a hypersensitivenes...

CLASSIFICATION AND TREATMENT OF NEPHRITIS ACCORDING TO FUNCTIONAL TESTS

Nephritis may be defined as an affection of both kidneys in which inflammatory changes occur but do not lead to suppuration. Functionally the kidney consists of two distinct apparatus, the tubular and the vascular, the latter comprising the glomeruli with their afferent and efferent branches and the small branches of the renal artery passing between the tubules. By means of poisonous chemicals it is possible to injure either system at will and to study the other in its normal condition. Salts of chromium or corrosive sub-limate cause marked changes in the epithelium of the convoluted tubules, with no changes in the glomeruli. In such a tubular nephritis, large amounts of albumin and casts are found. On the other hand, a nephritis produced by cantharides or arsenic affects especially the glomeruli, and in this form, known as vascular nephritis, there occurs little albumin and few casts, but many red blood-corpuscles. A series of experiments recently carried on by Schlayer