The tone and caliber of the blood-vessels are controlled by certain vaso-motor nerves, which are distributed among the muscular fibers of the walls.

Now the vaso-motor center may be excited to increased activity by influences reaching it from various parts of the body, or even from the brain itself.

Again, the normal influence of the vaso-motor center may be suspended for a time by what is known as the inhibitory or restraining effect.

We have in the act of blushing a visible example of sudden enlargement of the smaller arteries of the face and neck, called forth by some mental emotion which acts on the vaso-motor center and diminishes its activity.

Then the result of the mental emotion is to cause the vaso-motor nerves to exercise a more powerful control over the capillaries, thereby closing them, and thus shutting off the flow of blood.

In brief, all over the body, the nervous system, by its vaso-motor centers, is always supervising and regulating the distribution of blood in the body, sending now more and now less to this or that part.

First, the skin regulates the loss of heat by means of the vaso-motor mechanism.

Hence, any action of the vaso-motor mechanism which causes dilatation of the cutaneous capillaries, leads to a larger flow of blood through the skin, and will tend to cool the body.

In other words, the sweat glands may be stimulated to increased action both by an increased flow of blood, and also by reflex action upon the vaso-dilator nerves of the parts.

These two agencies, while working in harmony through the vaso-dilators, produce phenomena which are essentially independent of each other.

In the kidneys, as elsewhere, the vaso-motor nerves are distributed to the walls of the blood-vessels, and modify the quantity and the pressure of blood in these organs.

This, too, is beyond the control of the will, and is brought about by the vaso-motor nerves of the sympathetic system through a reflex arrangement, the center for which is the medulla oblongata.

First, we note the failure of the vaso-motor nerves to maintain the proper tone of the blood-vessels, as in the turgid face and the congested cornea of the eye.

Vaso-motor (Lat. vas, a vessel, and moveo, motum, to move).

Vaso-motor nerves cause contraction and relaxation of the blood-vessels.

La luz, que en un vaso, Ardía en el suelo, Al muro arrojaba La sombra del lecho; Y entre aquella sombra Veíase á intervalos, Dibujarse rígida La forma del cuerpo.

vasallo, m., vassal. vaso, m., vessel; pitcher; jug; (water) glass; lamp.

Quinine is, when given for a long period of time, a true poison to the vaso-motor nerves.

'Under the physical [psychical?] influence brought to bear by the application of the shift ... the oedema, which was due to vaso-motor trouble, disappeared almost instantaneously.

Y en bebiendo luego un buen vaso de agua.... DOÑA MATILDE.

come; I say *vanidad* f. vanity *vano* vain *vapuleo* m. flogging *vario* various; different; pl. several *vaso* m. glass, tumbler *vaya* (from *ir*) exclam.