How Is a Homeostatic System Formed?

Environmental Adaptation

• Organisms often adapt to their environment. Plants can gradually acclimate to a particular environment and adjust their physiology accordingly. However, if someone suddenly takes a plant to its old environment, it might adapt too slowly and may perish in an environment in which it originally thrived. Another example is the adaptation that a person goes through when she becomes addicted to drugs. The body changes its chemistry to adapt to the new substances, but when these substances are suddenly taken away, the body experiences withdrawal symptoms that can be fatal. Every change that an organism experiences can lead to a different modification that creates the opposite effect in the effort of achieving balance.

Set Points

• Biological organisms regulate concentrations of ions, molecules and temperature to keep up homeostasis. Biological organisms have phenotype flexibility. In other words, they can adjust their physiology based on particular circumstances. Homeostatic systems have set points the system tries to return to. The organism compares the real physiological state to the reference signal. The genome, nervous system, endocrine system and various other processing structures send signals that are in proportion to the deviation of the internal state. In response to the signal, the system sends enzymes and triggers reactions in organs and tissues to respond to the deviation.

Evolution

• The ways in which organisms adjust their phenotype flexibility results from common problems that the organism faces. For example, most land insects are under serious risk of dehydration. Insects have various organs that help them maintain stable water balances. Numerous Malpighian tubules control the release of urine and the absorption of water through the rectum. Information processing systems decide how the insect's body manages its water intake and release.

Embryogenesis

• Homeostasis begins during embryogenesis, which is the set of processes that occur when fertilization leads to the development of an organism. Cells divide and create new cells while arranging themselves. For tissue to grow and develop a structure, cells must be produced faster than they are lost.