Explain the kidney function in human biology, Biology

Assignment Help:

Explain the Kidney Function in human biology?

Blood first enters the capillaries in Bowman's capsule where it is filtered. The pores in the capillary walls allow water and small molecules to pass through, but are too small to allow red blood cells and large protein molecules to pass. The process by which material is filtered into Bowman's capsule is not very selective, and some of these substances that are of value to the body need to be reclaimed. Material filtered through the capillary walls into Bowman's capsule flows along the renal tubules. The process by which material is returned to the blood through the walls of the tubules is called tubular reabsorption.

Sodium, potassium, calcium, other minerals, and glucose are returned by active transport. These substances then enter the capillaries by diffusion. Water is returned by osmosis mostly in the proximal convoluted tubule, following the movement of glucose. There is additional reabsorption of salts and nutrients from the distal convoluted tubule, but this section of tubule also removes wastes and other substances not originally filtered out by Bowman's capsule through a process called tubular secretion. The pH of the blood is adjusted by the secretion of hydrogen ions into the filtrate. Potassium ions, ammonia, and certain drugs are eliminated by secretion from the distal convoluted tubules.

The loops of Henle function to concentrate the filtrate by establishing an osmotic gradient in the extracellular fluid around the loops that will later pull water from the collecting ducts. The ascending limb of the loop pumps NaCl out by active transport, but the ions cannot diffuse back in because this portion of the loop is impermeable to water. Salts can diffuse into the descending limb, but these are pumped out again when they reach the ascending loop, increasing the extracellular ionic concentration. When the filtrate reaches the collecting ducts, its osmotic concentration is much lower than the extracellular fluid of the medulla, so it loses water by osmosis and becomes more concentrated. As much as 99% of the water that goes through the tubules and collecting ducts is returned to the blood.

 


Related Discussions:- Explain the kidney function in human biology

The glomerular filtrate in comparison to the blood, What is the main transf...

What is the main transformation presented by the glomerular filtrate in comparison to the blood? Glomerular filtrate is the name given to the plasma after it has passed the glo

Compare and contrast covalent and ionic bonds, Compare and contrast covalen...

Compare and contrast covalent and ionic bonds in molecules, give an example of each.

Explain about g-protein, Explain about G-protein   A.  When an agonist ...

Explain about G-protein   A.  When an agonist binds to the binding site of a G-protein-coupled receptor (GPCR), this leads to GTP displacing a GDP bound to the alpha subunit of

What are the possible effects on the fetus, What are the possible effects o...

What are the possible effects on the fetus if, during pregnancy, the mother (a) smokes, (b) catches rubella?   a) Smoking during pregnancy can lead to an underwe

What are the typical fauna of the taigas, What are the typical vegetation a...

What are the typical vegetation and the typical fauna of the taigas? Taiga, or the boreal forest, is characterized by coniferous trees, pine forests. There are also mosses, lic

Describe in brief about retina, Describe in brief about retina The reti...

Describe in brief about retina The retina is a highly complex layer of nervous tissue. The photoreceptors are rods and cones for scotopic and photopic vision respectively. The

Mosaic and regulative eggs, Mosaic and Regulative Eggs Eggs as well a...

Mosaic and Regulative Eggs Eggs as well as early cleavage embryos are occasionally divided into two categories: i) Mosaic or determinate embryos and ii) Regulative or i

Why we use overgloves, Q. Why we use Overgloves? Overgloves are used wh...

Q. Why we use Overgloves? Overgloves are used when: supplies or equipment are retrieved or returned to the Dispensary or from the unit mobile the operator is charting

Joint, Ask question #Minimum 100 words what is joint accepted#

Ask question #Minimum 100 words what is joint accepted#

Plant, what is the scientific explanation of "touch me not" plant that can ...

what is the scientific explanation of "touch me not" plant that can react due to any touch

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd