Investigating what makes you tick
WHATEVER activity we are involved in, be it sitting and reading
The Micro User or competing in a quadrathon, our brains make sure
that the body processes are maintained between fine limits.
This system of feedback, or homeostasis, involving the body organs
and the brain is essential to life. At last there is a software
package designed to demonstrate this vital physiology in a form
intelligible to all biology students.
Physiological Simulation is an MEP subsidised biology package
published by Heinemann Computers in Education. It is designed
for use with pupils aged 13 and above.
The program's greatest asset is that it allows physiological
investigations to occur which would not normally be within the
scope of school laboratory facilities. It also allows the effect
of a simple variable to be assessed in a complex physiological
system.
Put simply, the user (playing the part of the brain) has to keep
the body, (played by the computer) alive while performing one
of a dynamic range of activities, such as running, sleeping, walking,
hockey, rock-climbing and rowing.
The user begins by opting to use preset values or to input pupil
details (sex, age, mass, blood volume and vital capacity), activities
(already mentioned) and parameter values (breath. volume. rate
of breathing and sweating rate).
Do not let the idea or measuring pupil blood volumes put you
off. The detailed booklet provided has a simple-to-use nomogram
which enables this variable to be quickly calculated from the
subject's height and mass. Vital capacity is easily measured in
class using the normal spirometer apparatus.
Once these data have been provided dynamic graphs show the person
5 progress over a simulated 50 minute period. A colour monitor
is an advantage as the background colour changes from red to blue,
while the display remains white.
Apart from a clock showing the time elapsed, graphs of oxygen
debt, sugar used, oxygen supply, body temperature and water loss
are all provided. A word of warning: the interpretation or the
oxygen debt graph needs clear explanation before the simulation
otherwise it is very misleading.
The user must maintain all five of these variables within displayed
upper and lower limits or the activity ceases and a message indicates
the reason for failure, for example "Person is DEAD"!
The secret of success is to freeze the action when the body is
in danger and change either the parameters or activity. Unfortunately
the axes of the graphs do not show any scale or units. This facility
would make the graphical display more intelligible and bring the
software up to A-Level requirements.
Once the simulation has finished it is possible to begin the
program again, terminate it or display further options such as
beginning a comparative simulation for a second person. After
such a comparison the user can replace ~ any one of the two sets
or data and try another comparison.
The program is well "student-proofed". It is very difficult to
make an error which throws the program haywire.
Clearly such a package is of most use in a teacher demonstration
situation -maybe using more than one monitor if the group is large
- or possibly by the more able pupil in small well-supervised
groups.
Hard copy is not provided for users. This is a pity as a printout
would provide a permanent study/revision piece.
A program is only as good as the mathematical model it is based
on. The medical data used was mainly derived from a Swiss sample
taken in 1956-57.
One cannot help but wonder how different the pupils are today
when compared with those used for the present values. but the
program's saving grace is that it does allow fresh data to be
inserted. The source of the calculations used to plot the graphs
is not disclosed - a glaring omission.
The notes for teachers are well documented on the whole and particularly
useful for teachers using computer-aided learning material for
the first time. It is unfortunate that no bibliography is provided
to aid teachers in background/further reading.
Visual presentation in this software package is top class. The
program is fun to use. but be prepared to spend an hour or two
in preparation time to master its principles first. It is not
an instant lesson, nor is it designed to be one. but it is a flexible
and powerful educational tool which should be in every biology
teacher's "toolbox".
At £12.50 - for disc or tape - this package is good value for
money and recommended for use by all secondary school biologists.
Peter Hillman
