Homeostasis works to maintain the organism's internal environment,
where the body's processes are able to function at a level that would
allow life to continue in that organism. The three systems which are
controlled by homeostasis are the respiratory, cardiovascular, and
Changes to the cardiovascular system are often a result of changes in
the activities of other systems. The heart rate, the cardiac output
and the blood pressure change to different degrees of bodily activity.
The heart rate slows and cardiac output falls when demands on bodily
systems are less high. However the opposite is true when demands on
the bodily systems are high, the heart rate increases and also the
cardiac output also increases.
Breathing is essential to life: it allows oxygen to be taken in and
carbon dioxide to be given off. Processing food in order to obtain the
energy needed for a wide range of activities is dependent on a
continuous supply of oxygen to the cells. The respiratory system takes
in oxygen and excretes carbon dioxide. Homeostasis allows the
respiratory system to take in oxygen in many different situations
where the breathing rate is irregular.
Muscular activity requires a source of energy. When muscles are
working aerobically, three main products are created: heat, carbon
dioxide, and water. The heat produced by active muscles helps to
maintain body temperature, so muscle is contributing to heat
homeostasis. However, if more heat is being produced than is needed,
as for example during vigorous exercise, the excess heat has to be
lost from the body to prevent a harmful rise in body temperature.
Therefore, homeostasis helps by controlling the bodies physical output
and the stress that is put upon muscles, which keeps the muscles from
All systems must have homeostasis to maintain stability and to
survive. Homeostasis is so important because it can allow an animal to
adapt to a changing environment. The body attempts to maintain a
constant level of physical output to achieve homeostasis. However, it
can only work within its limits, where extreme conditions can disable
the negative feedback mechanism.
In humans, the process is a little different. It involves a constant
monitoring of lots of different factors. An example of one of the