AORTIC VALVE INCOMPETENCE
59
cortex and kidney, the absence of blue from the renal medulla, the deep blue
of the adrenal medulla, the absence of blue from the adrenal cortex. Note
that with exposure to air the blue intensifies in the parts «already blue and
that other parts not previously blue become so, e. g. renal medulla.
Cut open a piece of the gut and note that the mucosa is blue, the muscular
coat not so. Noto that the liver and lung become mottled with blue.
Expose a portion of the spinal cord ; note that the surface of the cord
becomes bluish under exposure, and that the cross-section of the cord, though
not blue when first cut across, becomes blue, the grey matter in a fewsoconds
taking a bright blue tint. The urine is slightly greenish.
X. To estimate the actual pressure values of the membrane manometer’s
records, Obs. 86 and 37, it is necessary to gauge the manometer. This may
now be done as follows :
Calibration of the membrane manometer. The manometer and its recording Obs. 37 (cont.).
parts were left undisturbed in their position on the kymograph, except for Cahbratlon
disconnexion from the arterial cannula. Join the side-branches of the T-tube manometer1*0
leading from the kymograph’s reservoir bottle to the connecting-tube of the
membrane manometer on the one hand and to the connecting-tube of the Ifg
manometer on the other. Lower the reservoir bottle to the level of the
manometers. Open the top branch of the proximal limb of the Hg mano¬
meter tube and allow the Hg columns to balance at their zero, and then close
it again. Move the kymograph recording-paper to a clean part of the surface,
and mark the level of the manometer-lever, thus getting zero mark (text-
fig. 26). Then raise the reservoir bottle slowly till the Hg manometer shows
25 mm. pressure. Mark the membrano manometer’s lever record at this
pressure 25. Raise the reservoir bottle till the Hg manometer shows
successively 50, 75, and 100 mm. pressure, marking the corresponding heights
of tho membrane manometer’s record. Shift the recording surface to a fresh
place and reverse the process, lowering tho pressures.
With these marks as standards, note the values of the systolic and
diastolic pressures obtained before and after breaking the aortic valves.
The kind of result you may expect to find is instanced by the following quotation from
data yielded by an individual class experiment : Before the breaking of the aortic valve,
systolic pressure 55 mm. Hg, diastolic pressure 36 mm. Hg ; after the breaking of the
valve, systolic pressure 53 mm. Hg, diastolic pressure 22 mm. Hg.
XI. Remove the heart from the preparation. Dissect it under water,
and ascertain the valvular lesion you have made. The usual lesion is a large
tearing away of the attached base of one of the cusps from the wall of the
Valsalva sinuses.
i 2