Internal Environment and Homeostasis in Organisms

Trachea

Trachea are elongated cells, with thick walls and lose their cytoplasm at maturity, so they are dead cells. The terminal walls dissolve and form continuous tubes called vessels.

Sieve Tube

These cells are at the end to end and form long sieve tubes. Polyhedral cells of epithelium lining the trachea have cilia that beat synchronously to move substances.

DNSO

The fibers are arranged in different directions and at different levels, allowing them to endure stretching in all directions.

Internal Environment

Unicellular organisms trade directly with the extracellular environment they live in, while multicellular organisms rely on an internal environment as an intermediary between the external and intracellular environments.

Benefits

• Cells provide a suitable environment for their operation.
• Allows different exchanges between cells.
• Provides relative independence from changes in the external environment.

In plants, the internal environment consists of liquids circulating through intercellular spaces, xylem vessels, and phloem. In animals, the internal environment includes blood plasma and interstitial fluids.

Homeostasis

Homeostasis is the set of physiological processes that maintain stability in the internal environment of organisms. In animals, this stability is maintained by coordinated activity of the circulatory, nervous, and hormonal systems, as well as organs that exchange with the external environment.