MANUAL PHYSIOLOGY PRACTICAL - Repository:The Medical ...

FM/UOJ
Experiment R1
GRAPHIC RECORDING OF RESPIRATION
The circumference of the chest increases during inspiration and decreases during
expiration. This principle is used to record and study the qualitative aspects of respiratory
movements.
Instrument:
Stethograph
Method:
Check the system for leaks first; adjust the recording pen to write on the
kymograph drum; blow through the system to increase the pressure slightly so that the
pen rises about 2 cm and clamp the opening; rotate the drum to draw a line of about 2 cm;
and leave the system undisturbed for 2 minutes. If there is any leak the pen will drop
down.
Apply the stethograph to the chest of the subject snugly and adjust the pressure in
the system to give a deflection of about 2.5 cm with each normal breath. Record the chest
movements while the subject performs the following procedures.
1. The subject breathes quietly at rest.
2. The subject takes a deep breath and holds the breath until the breaking point is
reached. Keep recording until the breathing comes back normal pattern.
3. The subject breaths pure oxygen and holds breath at the end of normal inspiration
until breaking point is reached. Keep recording until respiration comes back
normal pattern.
4. The subject breathes as fast and deep as possible. The subject relaxes when it
becomes impossible to breath any more. Keep recording until the respiration
comes back to normal.
5. Allow the subject to relax and connect one-meter long tube to the mouth piece
with the nose closed. Remove the tube when a steady state of breathing is reached
and record until the breathing comes back to normal pattern after removing the
tube.
6. The subject coughs and sneezes violently.
Respiration
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