- Specialized proteins called transporters are located on the membranes of the various cells of the nephron.
- These transporters grab the small molecules from the filtrate as it flows by them.
- Each transporter grabs only one or two types of molecules. For example, glucose is reabsorbed by a transporter that also grabs sodium.
- Transporters are concentrated in different parts of the nephron. For example, most of the Na transporters are located in the proximal tubule, while fewer ones are spread out through other segments.
About the kidneys , you have any doubts, please click on this sentence, I'll give you the answer
In the nephron, approximately 20 percent of the blood gets filtered under pressure through the walls of the glomerular capillaries and Bowman's capsule. The filtrate is composed of water, ions (sodium, potassium, chloride), glucose and small proteins (less than 30,000 daltons -- a dalton is a unit of molecular weight). The rate of filtration is approximately 125 ml/min or 45 gallons (180 liters) each day. Considering that you have 7 to 8 liters of blood in your body, this means that your entire blood volume gets filtered approximately 20 to 25 times each day! Also, the amount of any substance that gets filtered is the product of the concentration of that substance in the blood and the rate of filtration.
- Renal Capsule - a thin, outer membrane that helps protect the kidney
- Cortex - a lightly colored outer region
- Medulla - a darker, reddish-brown, inner region
- Renal Pelvis - a flat, funnel-shaped cavity that collects the urine into the ureters
If you look closely at the cortex and medulla, you can see many tiny, tubular structures that stretch across both regions perpendicular to the surface of the kidney. In each kidney, there are one million of these structures, called nephrons. The nephron is the basic unit of the kidney. It's a long, thin tube that is closed at one end, has two twisted regions interspaced with a long hairpin loop, ends in a long straight portion and is surrounded by capillaries.
About the kidneys , you have any doubts, please click on this sentence, I'll give you the answer
Your kidneys are two bean-shaped organs, each about the size of your fist. They are located in the middle of your back, just below your rib cage, on either side of your spine. Your kidney weigh about 0.5 percent of your total body weight. Although the kidneys are small organs by weight, they receive a huge amount -- 20 percent -- of the blood pumped by the heart. The large blood supply to your kidney enable them to do the following tasks :
