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

Recycling of plasma membrane components, Recycling of Plasma Membrane Compo...

Recycling of Plasma Membrane Components During exocytosis secretory vesicles fuse with plasma membrane, adding to the membrane surface area. Yet, the surface area of plasma me

How can you convert 147.05mg%, How do you convert 147.05mg% of plasma gluco...

How do you convert 147.05mg% of plasma glucose to mM/L please show work.

Determine the symptoms of cholera, Determine the Symptoms of Cholera  A...

Determine the Symptoms of Cholera  An infective dose of around one million organisms should be ingested to cause illness. The bacteria adhere to the small intestine wall, where

Augmentation therapy, Augmentation Therapy: The functional gene is intr...

Augmentation Therapy: The functional gene is introduced in addition to the defective gene endogeneous to the cell(s) in this somatic cell gene therapy,  i.e. the improved  cell

Define gray matter and white matter of the spinal cord, Q. What are the res...

Q. What are the respective constituents of the gray matter and of the white matter of the spinal cord? The gray matter or gray substance of the spinal cord contains predominant

Write the positive ion isoelectronic with neon, Write the positive ion isoe...

Write the positive ion isoelectronic with neon The positive ion isoelectronic with neon must have 10 electrons and 11 protons, and thus must have an  atomic number = 11. This i

What are called transactions, What are called Transactions? The grouped...

What are called Transactions? The grouped SQL statements are known as Transactions (or) A transaction is a collection of actions embused with ACID properties.

What are the diagnostic models, Diagnostic Models Study models made fro...

Diagnostic Models Study models made from impressions of the arches are invaluable for diagnosis and treatment planning. The model must be mounted on an adjustable or semi adjus

How are animals classified according to the germ layers, Q. How are animals...

Q. How are animals classified according to the germ layers present in their embryonic development? Cnidarians are diploblastic, that is they present only ectoderm and endoderm.

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