Homeostasis. The biological definition of homeostasis is âthe tendency of an organism or cell to regulate its internal environment and maintain equilibrium, usually by a system of feedback controls, so as to stabilize health and functioningâ.ositive feedback mechanisms. A positive feedback mechanism is the exact opposite of a negative feedback mechanism. With negative feedback, the output reduces the original effect of the stimulus.
Bacteria produce disease in one of two general ways; some bacteria damage the cells and tissues of the infected organism directly by breaking down the cells for food, other bacteria release toxins (poisons) that travel throughout the body interfering with the normal activity of the host. Pathogens.
Primary bacterial diseases are caused by invasion of bacteria that cause disease with no other predisposing factors. Secondary bacterial diseases are caused by invasion of bacteria after a predisposing condition, such as viral infections, stresses, tissue injuries, and dietary upsets.A bacterial disease may affect a single tissue or organ, or it may affect multiple tissues and organs of the animal.iruses often infect specific types of cells causing damage to the tissues or organs that those cells make up. Similar to bacte-rial disease, viruses can be found in the bloodstream, which is called viremia. Viruses are causative agents of many types of animal diseases.