A THIRDSYSTEM is the "ADRENAL SYSTEM" which includes "the pituitarybody, the adrenals and the thyroid gland including theparathyroids."
"Theanterior
pituitary body governs, through the posterior pituitary body, all theoxidation processes of the body. The center in the posterior pituitarybody through which the anterior pituitary body governs the adrenals alsocontrols the functional activity of the thyroid gland, and thus constitutes the'adreno-thyroid' center; which is governed by the test organ (the sensory organbetween the two lobes of the pituitary body). Theadrenal system is "the immunizing apparatus of the body" and itsprincipal function is to supply an internal secretion which absorbs the oxygenof the air to carry it to the tissues. It is the system
through the tract of some of thecerebral nerves to their distribution: - through the trigeminus in part to theinterior of the eye, through the hypoglossus to the tongue, through fibres ofthe vagus to the heart and in limited number to the lungs and to theintestines. They make their exit, through the anterior roots of the spinalnerves, then pass through the visceral branches into the ganglia of thesympathetic cord. The Internal Secretions and the Principles ofMedicine, page 463> that there is no individual center in the medulla to becalled "vaso-motor center" and says "the general vaso-dilationafter section of the medulla is due to the interruption ofthe stream of general motor impulses through which tonic contraction of thearteries is maintained, and which the medulla seems to transmit." Hethinks the vaso-motors for the arterioles are from the sympathetic system undercontrol of the sympathetic center and that the larger vessels are controlled bythe bulbar vaso-motor center. Sajous thinks "thedepressor nerves are those through which the thyroid center regulates thecirculation of the anterior pituitary body and of the thyroid apparatus." THEVASO-MOTORS TO THE HEAD ARE MOSTLY FROM the cervical sympathetic, to theupper extremities "through the anterior roots of the middle dorsalnerves, into the thoracic sympathetic, and upwards to the last thoracicganglion, and from thence to the rami communicantes to the brachial plexus(Schiff, Cyon)," to the lower extremities "through the nervesof the lumbar and sacral plexuses into the sympathetic, and from thence to thelower limbs (Pfluger, Schiff, Cl. Bernard)," to the skin of the trunkthrough the dorsal and lumbar nerves, to the lungs "from the dorsalspinal cord through the first thoracic ganglion (Brown-Sequard, Fick andBadoud, Lichtheim) to the abdominal viscera from the splanchnic"(v. Bezold, Ludwig and Cyon). Gaskell observed under the microscope thedilatation produced by stimulation of the nerve to the mylo-hyoid muscle of thefrog. The nervi erigentes from the sacral plexus when stimulated causethe arteries of the penis to dilate. Buchheim obtained stimulatory effects onthe sympathetic and vagus in the neck according to the site ofapplication." Further the occurrence of the movement after themoment of stimulation is distinctly delayed. Reflextime or the time for carrying impulses by means of the afferent nerves throughthe cord to the efferent varies, in the frog being .0008 to .015 second, but isincreased by "almost 1-3 if the impulses pass to the other side of thecord." - In the above case, the contractions will be more violent onthe side irritated, but it must not be assumed that the effect is always ,inproportion to the strength of the stimulus. The greater thesensitiveness of the nerve, the less pressure should be at first employed. Inapplying interrupted vibration to the spine place the ball vibratode over thesite of the ganglion and make the pressure close to the spinous processes andbetween the transverse processes, or between the ribs near the spine. :