As the bear enters hibernation, its metabolic processes such as body temperature, heart rate, and respiratory rate are reduced. But bears do not lower the body temperature as much as once thought. Their hibernation temperature is around 88 degrees and waking temperature is 100 degrees F. This relatively high sleeping temperature allows bears to become fully alert if aroused, perhaps to enable the bear to protect itself from predators and other dangers without unnecessarily taxing their energy reserves. Over the course of a hibernating season it is thought that bears use approximately 4 thousand calories a day, which results in a weight loss of about 20 percent of it body weight by spring.
<span>Nasal insufflation, also commonly referred to as snorting, is the inhalation of a crushed or powdered substance through the nose. It leads to a number of problems including perforation of the nasal septum, irritation of the nasal cavity, nose bleeds, and loss of smell.</span>
Answer:
The correct answer is ''G-protein coupled receptors on the surface of cardiac muscle cells.''
Explanation:
Adrenaline is a catecholamine whose pharmacological effects occur at alpha and beta adrenergic receptors. The mechanism of action of all beta adrenergic receptors is the activation of a G protein that activates adenylyl cyclase and increases cyclic AMP production. Adrenaline by b-adrenergic stimulus increases the contractile force of the myocardium (positive inotropic action) and increases the frequency in which the myocardium contracts (positive chronotropic action), consequently there is an increase in cardiac work, with a greater demand for oxygen due to the myocardium to be able to contract. Therefore, the blood flow to the heart is indirectly increased, bringing with it a greater supply of oxygen.
