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The vocal cords, as has been stated, lie parallel to each other, and the space between them is known as the glottis or chink of the glottis. Above the glottis and on opposite sides are two pockets or ventricles, and above these are the so-called false cords or ventricular bands. The pockets are, in fact, bordered below by the vocal cords and above by the false cords.
As previously stated, ventricular fibrillation is a very serious condition, and may be a cause of sudden death in angina pectoris, and is probably then caused by disturbed circulation in one of the coronary arteries causing an irregular blood supply to one or other of the ventricles.
In an irregularly acting heart the systolic pressure may vary greatly, from 10 to 20 mm. or more, and a ventricular contraction may not be of sufficient power to open the semilunar valves. Such beats will show an intermittency in the blood pressure reading as well as in the radial pulse.
Other terms applied to the condition have been "ventricular rhythm," "nodal rhythm" and "rhythm of auricular paralysis." The condition of the pulse has been Latinized as pulsus irregularis perpetuus.
Each of these systems of breath-control, opposed muscular action and ventricular, is in fact found on analysis to embody a misconception of scientific principles. Opposed-Action Breath-Control A curious misapprehension of mechanical processes is contained in the doctrine of breath-control by opposed muscular action.
Various stimuli coming through the pneumogastric nerves, either from above or from the peripheral endings in the stomach or intestines, may inhibit or slow the ventricular contractions. It seems to have been again shown, as was earlier understood, that there are inhibitory and accelerator ganglia in the heart itself, each subject to various kinds of stimulation and various kinds of depression.
In all Mammals, each cerebral hemisphere contains a cavity which is termed the 'ventricle, and as this ventricle is prolonged, on the one hand, forwards, and on the other downwards, into the substance of the hemisphere, it is said to have two horns or 'cornua, an 'anterior cornu, and a 'descending cornu. When the posterior lobe is well developed, a third prolongation of the ventricular cavity extends into it, and is called the "posterior cornu."
Compare the walls, lining, shape, size, etc., with the ventricle below. Cut off the end of the left ventricle about an inch above the apex. This will show the extension of the cavity to the apex; it will also show the thickness of the walls and the shape of the cavity. Split up the ventricular wall far enough to examine the mitral valve and the chordæ tendineæ from the lower side.
It has been found to be associated with such congenital lesions of the heart as an open foramen ovale or foramen Botalli, or with an imperfect ventricular septum, and perhaps with tricuspid stenosis in short, a cardiac congenital defect. The right ventricle becomes hypertrophied, if the child lives to overcome the obstruction.
In the last few years it has been discovered that the auriculoventricular handle, or "bundle of His," has a necessary function of conductivity of auricular impulse to ventricular contraction. It has also been shown that extrasystoles, meaning irregular heart action, may be caused by impulses originating at the apex, at the base or at some point in the right ventricle.
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