. Directions for laboratory work in physiology. Physiology. 28 EXPERIMENT V. recorded contraction the line MN, perpendicular to the base line. To fix the point at which the second contraction began, draw on the curve two fine parallel lines, one just above and one just below the line traced by the lever, as at AB, to aid the eye in fixing the point. Draw through it the line OP and estimate MO, the latent period, in thou- sandths of a second. One double vibration of the fork is ten thousandths of a second. A good way of ascertaining the length of the latent period, is to estimate the value of o
. Directions for laboratory work in physiology. Physiology. 28 EXPERIMENT V. recorded contraction the line MN, perpendicular to the base line. To fix the point at which the second contraction began, draw on the curve two fine parallel lines, one just above and one just below the line traced by the lever, as at AB, to aid the eye in fixing the point. Draw through it the line OP and estimate MO, the latent period, in thou- sandths of a second. One double vibration of the fork is ten thousandths of a second. A good way of ascertaining the length of the latent period, is to estimate the value of one millimeter of drum surface in thousandths of a second, by dividing the time of one double vibration of the fork. Fig. 6. Method of preparing myogram for de- termination of latent period. by the number of millimeters in the wave which is recorded most nearly between MO, and multiplying this value by t4^ number of millimeters in the recorded latent period. To detenPiine the period of contraction, draw TQ per- pendicular to MN and tangent to the muscle curve at Q. With a radius equal to the length of the writing lever and a center on the base line traced by the muscle lever, as at R, revolve Q to this base line at S. draw the perpendicular UV through S, and estimate the number of thousandths of a second between OU. To do this count the complete waves, and estimate in tenths the fractions of waves. The line UV must not be drawn through Q, because the distance WQ is due to the fact that the muscle lever draws an arc instead of a straight line. To determine the period of relax- ation, draw XY through the point where the muscle curve strikes the base line at X. State in notes length of latent period, contraction period, and relaxation period, in tabular form. Also mention the most likelv sources of Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may
Size: 2543px × 983px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectphysiology, bookyear1
