The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of:?
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D) Loop of Henle\n\nIt is the only part of the nephron of those listed in the choices that is actually in the renal medulla
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permeability of the cell membrane
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OSMOSIS IS THE MOVEMENT OF WATER MOLECULES ACROSS THE CELL MEMBRANE.  IF THE OSMOTIC PRESSURE IS HIGH i.e THERE ARE MORE WATER MOLECULES INSIDE THE CELL THEN WATER MOVES OUT TO LESSEN THE PRESSURE.  IF THE OSMOTIC PRESSURE IS VERY LOW THEN WATER MOLECULES MOVE INTO THE CELL TO KEEP THE PRESSURE OUTSIDE AND INSIDE EQUAL.\n\n(IT IS RUDE TO WRITE IN ALL CAPITALS)
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Given that a certain type of molecule is small enough to permeate through the cell membrane, the most important factor influencing the rate of diffusion is the concentration gradient.  This is simply the difference in concentration levels of the substance between the outside and the inside of the cell.  The larger the difference in concentrations, the greater the rate of diffusion.
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Facilitated diffusion (or transport) is the diffusion across a membrane which is aided by a membrane protein usually by a channel or pore this allows molecules that cannot pass through the lipid bilayer to enter the cell. The process still occurs down a concentration gradient, like normal diffusion and it requires no energy unlike active transport. For more information you could try looking up passive transport.\n\nI hope this helps
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With facilitated diffusion, proteins are needed to make an opening in the cell membrane.  However, once this opening is there, particles diffuse from the side which has the higher concentration to the side with the lower concentration, just like regular diffusion.  (The difference in concentrations is called the concentration gradient.)\n\nIn active transport, much more effort is needed to make it happen.  For example, in phagocytosis, the cell wall actually engulfs a particle and brings it inside the cell.  The difference is between the transport being facilitated or being forced.
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I answered this already.\n\nhttp://answers.yahoo.com/question/index;_ylt=AmW0Em3eAdmFrnQMc4_Xilzsy6IX?qid=1006051323791\n\nWorks the same as if you were changing permeability. If you have more Na inside the cell, there is less drive for Na outside the cell to come in. Because Na only has a minor impact on the resting membrane potential, it won't change much, but it will hyperpolarize a bit (away from the Ena and towards Ek).
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In order to have osmosis first of all you need to have a semi-permeable membrane separating two solutions. In order to have net water movement from one solution to the other you need to have different concentrations of solutes that CANNOT pass through the membrane. These solutes are osmotically active: since they cannot pass through the membrane water has to move in order to equilibrate the osmotic pressures. If they could pass through the membrane then they would just diffuse from one solution to the other until their concentration equilibrates and thus they would not contribute to the generation of osmotic pressure. \n\nSo in two words, osmotically active substances with respect to a given semi-permeable membrane are solutes that cannot pass through the membrane.
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Osmosis is a type of diffusion that relates directly to water passing the cell membrane. Diffusion is particle movement down the concentration gradient or to an area of less concentration of any substance
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OPPS SORRY, I sent incomplete. Believe it or not, it is generally described as thus: The body wants to have 2/3 of the water inside the cells \n(intracellular fluid) and 1/3 of the water between the cells (extracellular) however a Teacher is probably looking for the technical name of: interstitial fluid
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Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration.
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1. I guess You think about the nexuses. Its a metabolic and ionic connection of cells in form of ionic channels (built by proteins called conexones or conexone proteins).It provides rapid transport of membrane polarization changes. Its a form of electric synapses.\n2.I guess You think about the lysosomes. They're created by Golgi's Apart ('Trans" side).Lysosomic enzymes are created by Rough Endoplasmic Reticulum and GA. Lysosomical endoenvironment's pH is about 5. Function- to connect with endosomes, phagosomes and autophagosomes and to catalyze and guide analysis reaction (some kinds of digestive reactions).
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http://www.biologyreference.com/Ve-Z/Water-Movement-in-Plants.html\n\nThe Cohesion-Tension Theory\nThe major mechanism for long-distance water transport is described by the cohesion-tension theory, whereby the driving force of transport is transpiration, that is, the evaporation of water from the leaf surfaces. Water molecules cohere (stick together), and are pulled up the plant by the tension, or pulling force, exerted by evaporation at the leaf surface.\n\nWater will always move toward a site with lower water potential, which is a measure of the chemical free energy of water. By definition, pure water has a water potential of 0 MegaPascals (MPa). In contrast, at 20 percent relative humidity, the water potential of the atmosphere is -500 MPa. This difference signifies that water will tend to evaporate into the atmosphere. The water within plants also has a negative potential, indicating water will tend to evaporate into the air from the leaf. The leaves of crop plants often function at -1 MPa, and some desert plants can tolerate leaf water potentials as low as -10 MPa. The water in plants can exist at such low water potentials due to the cohesive forces of water molecules. The chemical structure of water molecules is such that they cohere very strongly. By the cohesion-tension theory, when sunlight strikes a leaf, the resultant evaporation first causes a drop in leaf water potential. This causes water to move from stem to leaf, lowering the water potential in the stem, which in turn causes water to move from root to stem, and soil to root. This serves to pull water up through the xylem tissue of the plant.\nFrom Root to Leaf\nPlants have root hairs and often mycorrhizal fungi at the root surface, both of which serve to filter the soil water as it enters the plant. Mycorrhizae are symbiotic associations between plant roots and fungi. The root cells and mycorrhizal fungi both actively uptake certain mineral nutrients. Mycorrhizae can be particularly important for the uptake of phosphate. The active uptake of minerals by living cells of the root and the subsequent transfer of minerals to the xylem can result in positive root pressures, with water potentials above 0 MPa. This occurs only under certain conditions, such as at night or during rainstorms, when water loss from the leaves is minimal. Such positive root pressures disappear with the onset of leaf transpiration.\n\nWater molecules move from the soil into living cells of the root, and eventually into the transport cells of the xylem, known as tracheids and vessels. These xylem cells are dead and hollow, allowing rapid water transport. They also have hardened cell walls to help them resist the tendency to collapse as water is sucked through them. Both tracheids and vessels \n\n \nA drop of guttation, water extruded by a plant's root pressure, on a blade of grass. have pits on the sides of their walls, which include porous areas for side-to-side transport. Unlike tracheids, a vessel is composed of many cells stacked end to end, with perforations between cells, allowing for more efficient transport.\n\nThe long-distance transport of the water molecule occurs first within the xylem cells of the root, then the xylem of the stem and branch, and then into the xylem of a leaf midrib and vein. Driven by transpiration, the water molecule is pulled from the nonliving tracheids and vessels of the xylem in the living cells of the leaf mesophyll (middle layer) and to the surface of mesophyll cell walls. The water molecule then evaporates into a leaf inter-cellular air space and finally out of a stomatal pore and into the atmosphere. Though photosynthetic action consumes some water, only a small fraction of the water that travels through the plant is used directly for the photo-synthetic reaction, which occurs in leaf mesophyll cells. Instead, most water is lost by transpiration through the stomates.\nThe Role of Stomates\nLeaves of land plants are covered with a waxy cuticle that pr
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likely to be due to the osmotic gradient set up due to the high carboydrate concentration in the cytosol.\n\non the other hand, who cares?
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Osmotic pressure is the hydrostatic pressure produced by a solution in a space divided by a differentially permeable membrane due to a differential in the concentrations of solute.\n\nOsmotic potential is the opposite of water potential with the former meaning the degree to which a solvent (usually water) would want to stay in a liquid.\n\nWhen a biological cell is in a hypotonic environment (the cell interior contains a lower concentration of water than its exterior), water flows across the cell membrane into the cell, causing it to expand due to osmotic pressure. In plant cells, the cell wall restricts the expansion, resulting in pressure on the cell wall from within called turgor pressure. The osmotic pressure π of a dilute solution can be calculated using the formula\n\n\nwhere\ni is the van 't Hoff factor\nM is the molarity\nR is the gas constant, where R = 0.08206 L atm/mol K\nT is the thermodynamic temperature (formerly called absolute temperature)\n\nNote the similarity of the above formula to the ideal gas law and also that osmotic pressure is not dependent on particle charge.\n\n[edit]\nApplications\n\nOsmotic pressure is the basis of reverse osmosis, a process commonly used to purify water. The water to be purified is placed in a chamber and put under an amount of pressure greater than the osmotic pressure exerted by the water and the solutes dissolved in it. Part of the chamber opens to a differentially permeable membrane that lets water molecules through, but not the solute particles. The osmotic pressure of ocean water is about 27 atm. Reverse osmosis desalinators use pressures around 50 atm to produce fresh water from ocean salt water.\n\nOsmotic pressure is necessary for most plants. It is the resulting turgor pressure on the cell wall that allows herbaceous plants to stand upright, and how plants regulate the aperture of their stomata. In animal cells which lack a cell wall however, excessive osmotic pressure can result in cytolysis.
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Oxygen transfers via osmosis through cell walls  from regions of high concentration (ie, the haemoglobin) to the tissue cells where there is a lower concentration. At the same time the tissue cells release carbon dioxide which lowers the partial pressure creating a diffusion gradient for the the oxygen to move along.
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diffusion is when molecules move from greater concentration to lesser, to achieve equilibrium. osmosis is the diffusion of water molecules.