Pulmonary hypertension is a rare lung disorder in which the arteries that carry blood from the heart to the lungs become narrowed, making it difficult for blood to flow through the vessels. As a result, the blood pressure in these arteries -- called pulmonary arteries -- rises far above normal levels.
Homeostatic Control Mechanisms Homeostatic Control Mechanisms are devices for maintaining or restoring homeostasis. They involve virtually all of the bodyâs organs and systems.
The ultimate control of homeostasis is accomplished by the nervous system (for rapid responses such as reflexes to avoid picking up a hot pot off the stove) and the endocrine system (for longer-term responses, such as maintaining the body levels of calcium, etc.).ost multicellular organisms have most of their cells protected from the external environment, having them surrounded by an aqueous internal environment. This internal environment must be maintained in such a state as to allow maximum efficiency. The ultimate control of homeostasis is done by the nervous system.