The image below may help you (ʘᴗʘ✿)...
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.
Since the average osmotic pressure of the brain is 300mM and the concentration of the solution is 280mM, that means there is 20mM difference between the brain cells and CSF. This will induce osmosis and cause water to move from the CSF into the brain until the concentration becomes same. Assuming brain volume is 1200ml and the CSF constantly replaced., then the estimation of fluid should be: 20mM/300mM * 1200ml= 80 ml
If it made percent it should be: 80ml / 1200ml= 6.67%
Answer:
C.
Explanation:
I have done this question before.
From the question you can immediately infer that it's either B or D, as A and C basically mean the same thing and it isn't anything related to a microscope. I can tell you now that you don't need an electron microscope to see cells, they're only required for the atomic level.
Therefore, the answer is B, as you can't see cells without a microscope but you only need a light microscope, not an electron microscope.
