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

Explain risk factor global perspective in heart dieases, Explain risk facto...

Explain risk factor at the global perspective in heart diease? While the risk of Cardio-vascular diseases has been found to be variable in different ethnic groups with the high

What is determined by tube feet, What is determined by tube feet? Hollo...

What is determined by tube feet? Hollow and fluid-filled tubes which are part of the water vascular system in Echinoderms. Muscles associated with tube feet allow them to be hy

Hemodynamic measurements of tricuspid stenosis, Q. Hemodynamic Measurements...

Q. Hemodynamic Measurements of tricuspid stenosis? Unless one suspects it clinically and echocardiographically, and plans the hemodynamic study - diagnosis of tricuspid stenosi

Explain soy protein concentrates - protein concentrates, Soy Protein Concen...

Soy Protein Concentrates The Association of American Feed Control Officials, Inc. (AAFCO) specifies soy protein concentrates as follows:  "Soy Protein Concentrate is organiz

What else is carried in the plasma, What else is carried in the plasma? ...

What else is carried in the plasma? In addition to proteins, plasma having salts (ions), glucose, lipids and amino acids, hormones, carbon dioxide and urea

Draw a graph for an iv multiple infusion of a drug, Draw A graph for an IV ...

Draw A graph for an IV multiple infusion of a drug, and label on the graph where the trough (predose) blood draw would be collected and where the peak (postdose) blood draw would b

Define epithelial tissue, Epithelial tissue the cells in animals which are...

Epithelial tissue the cells in animals which are closely packed in either single or multiple layers, and which cover internal and external surfaces both of the animal body. It is

Define precaution for estimation of vitamin c in lemon juice, Define precau...

Define precaution for estimation of vitamin c in lemon juice? 1. Rinse all glassware with 3% metaphosphoric acid before you begin your practical and subsequently each time you

Pollinia and massulae, Pollinia and Massulae In most cases the pollen ...

Pollinia and Massulae In most cases the pollen grains of each tetrad become separated from one another and they lie freely in the pollen sac. In some plants, mostly members of

Explain about the zygomycota - fungi, Explain about the Zygomycota - Fungi?...

Explain about the Zygomycota - Fungi? Fungi belonging to zygomycota are called zygomycetes. Hyphae in this sub-class are coenocytic. Asexual spores develop in sporangia at the

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