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.
Most homeostatic regulatory mechanisms involve negative feedback. Consider the control of body temperature, a process called thermoregulation. In thermoregulation, the relationship between heat loss, which occurs primarily at the body surface, and heat production, which occurs in all active tissues, is altered. The control center for thermoregulation is in the hypothalamus, a region of the brain (Figure 1-4a).