<span>The juxtaglomerular apparatus is a structure (formed by the distal convoluted tubule and the glomerular afferent arteriole) with the function in the regulation of blood pressure and the filtration rate of the glomerulus. Its primary components are:
</span> <span><span>· </span>the macula densa- specialized epithelial cells in the distal convoluted tubule (detect Na concentration),
</span> <span><span>· </span>juxtaglomerular cells- formed from the smooth muscle cells of the afferent arteriole (secrete renin),</span>
<span><span>· </span>extraglomerular mesangial cells (lacis cells)-unknown function.</span> <span> </span>
B. Bicarbonate
<em>The blood brings bicarbonate to the lungs, and then it is exhaled as carbon dioxide. The kidneys also help regulate bicarbonate... it is excreted and reabsorbed by the kidneys.</em>
<em>The body's main response is to get rid of more carbonic acid and hold on to as much bicarbonate base in the kidneys as it can.</em>
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Last option: Preserve an ecosystem

• The establishment of a bird reservation is a way to preserve an ecosystem because reservation provides suitable environment to organism. A healthy ecosystem means large number of biodiversity.