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

What is vertebrates, What is Vertebrates ? Vertebrates are animals that...

What is Vertebrates ? Vertebrates are animals that have vertebral columns, and include the following classes: Agnatha - jawless fishes (ex. lampreys) Chrondirichthyes - cart

How to produce a similar sickling effect, Which of the following amino acid...

Which of the following amino acids would you expect to produce a similar sickling effect if placed at position 6? Select all that apply. 1. Arginine 2. Leucine 3. Lysine

Lymph, why is it known as middle man

why is it known as middle man

Which heavy metals cause toxic pollution, Besides mercury which other heavy...

Besides mercury which other heavy metals cause toxic pollution? Examples of other heavy metals that cause toxic pollution are lead, cadmium and chromium.

Explain percutaneous interventions, Q. Explain Percutaneous Interventions ...

Q. Explain Percutaneous Interventions Over the last two decades, significant strides have been made in the field of Balloon Valvuloplasties both in terms of technique as well a

Nutrition in organisms, a project on different types of heterotrophic mode ...

a project on different types of heterotrophic mode of nutrition in organisms

The smooth er and rough er are similar functions, What functions of the smo...

What functions of the smooth ER and rough ER are similar?

The hybridization reaction, As double-stranded DNA is heated a temperature ...

As double-stranded DNA is heated a temperature is reached at that the two reaction strands divided.  This procedure is called as denaturation.  The temperature at that half of the

Counselling technique of diabetic patient, Counselling a diabetic patient a...

Counselling a diabetic patient and their family members is very important as patient has to modify the life style and diet and needs family support. Therefore it is important for y

1, what are the variations of the digestive system in animals? what musthav...

what are the variations of the digestive system in animals? what musthave caused these variation

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