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Tubular Secretion:Name several substances that are actively secreted into the tubular filtrate-H+, NH4+, Sodium, Water, Potassium, Urea, GlucoseStudy Analogy:Pretend you are cleaning your garage but the big door is stuck. You can only move things through the smaller “people” door. So, the cars & riding lawn mower have to stay in the garage. This is analogous to the pores in the glomerulus. They are larger than ordinary capillary pores but still not large enough to let everything out, so large things like proteins or blood cells stay in the blood. You have decided to haul almost everything out that you can fit through the smaller door. Out goes the hoses, garden implements, lawn chemicals recycling etc,without any sorting. You do this until you run out of energy. (Filtration – what fits goes through filters and it is controlled by size and the pressures.) After a short rest, you realize that you need some of this stuff. So you exert some more energy (active transport!) and put some of the materials back into the garage. For example, 13 of the 27 hoses are still good so they go back (like tubular reabsorption!!) The others are put out for the trash pickup (analogous to going to the bladder). After sorting, returning and discarding, you take one last look at what is now in the garage. Do you really need 13 hoses? Isn’t that one a little holey? So you take it back out of the garage and put it in the trash pile with the others. And just like tubular secretion, you have a last chance to excrete something you don’t need. Finally, your garage (and your blood) is clean!What is glomerulonephritis? How is it related to proteinuria?Acute inflammation of the kidney, usually from immune response. Maybe by damage to the kidney from too much protein in the urineRegulation of Kidney Filtration, Secretion, and Reabsorption to maintain Blood Pressure and Volume.The body needs to maintain a normal level of blood pressure and volume so that a normal range of nutrients aretransported to the cells of the body and an adequate amount of wastes are removed. Either abnormally high or low blood pressures have negative effects on the body. Note: An increase in blood volume (the amount of blood in your blood vessels) is often associated with an increase in blood pressure.Nervous System:Constriction and dilation of arteries.What happens to blood pressure when the arteries constrict?Blood pressure rises when arteries constrictWhat happens to blood pressure when the arteries dilate?Blood pressure drops when they dilate. 4
Constriction of afferentnephron arterioles and dehydration.When you are dehydrated, the body often needs to conserve water. The constriction of the afferent arterioles will decrease the amount of filtrate and consequently decrease your urine output.Constriction of efferentnephron arterioles and over-hydration (drinking too much water).What happens to the rate of kidney filtration when the efferent arterioles constrict?