An increase in volume DECREASES the pressure in the chest (pressure and volume vary inversely when temperature is held constant -- Boyle's law). Gas can only flow from an area of higher pressure to an area of lower pressure. It can't go uphill -- ever. It can only go from high to low pressure. When the diaphragm and intercostals contract, the diaphragm flattens and the rib cage rises. That increases the volume of the chest. That increase in volume decreases the pressure inside the chest (temperature is held constant -- because the temperature of the chest cavity does not change appreciably. It remains at body temp.). Air then flows from the area of higher pressure (atmospheric) to lower pressure (intrathoracic). That continues until the pressures are equal.
When the diaphragm and intercostals relax, the chest cavity decreases in size, the pressure increases to above atmospheric, and gas flows again from the area of higher pressure (intrathoracic) to lower pressure (atmospheric) until they are again equal.
It has nothing to do with the concentration of oxygen. You can ventilate a lung with ANY gas. It has to do with the change in pressure and only the change in pressure -- which is a function of the volume of the chest cavity.
Depend if you are more creative or more a solver(good in math).
When blood is in the lungs,
where oxygen is plentiful, oxygen easily binds to the first subunit and then quickly fills up the remaining ones. Then, as blood circulates through the body, the oxygen level drops while that of carbon dioxide increases. In this environment, hemoglobin releases its bound oxygen.
The correct option is RESILIENT.
The Alaskan forest usually undergo fire incident every year in order to enhance nutrient cycling of the ecosystem. Alaskan spruce is one of the plant find in the Alaskan forests and it is a very resilient plant, in that, when it is destroy by fire incident, it quickly grow back.
<span>Answer:
Set point theory suggests that our body has a particular range of weight that it is comfortable in, usually about 10% of a body’s weight. That means, if you weight 175, you have about an 18 pound range; if you weigh 325, you have about a 33 pound range. Most people lose and gain within this set point on a pretty regular basis. They may put on a little weight in the winter and lose it in the spring. Or get busy and drop a little weight. Or gain a little when stressed. Or lose a little during an illness. Or whatever. Movement within this range is normal. However, movement outside of that range is not. In fact the body seeks homeostasis – that is the body seeks to stay within that range. To move outside of that range something must go on, something must happen to the body.</span>
