[Biology Class Notes] on Loop of Henle Pdf for EXAM

The human kidney comprises a million nephrons which are the filtering units of this complex and highly vascular organ. Each filters out water and solutes from the blood which passes through it into the surrounding space and is the cavity which is between the walls of the cup.The other part looks  like the form of a U-shaped loop carrying the filtered fluid deep down into the medulla. 

The Function of the Loop of Henle

The function is  to reabsorb the water and the sodium chloride from the filtrate. This helps to conserve water for the organism, which results in highly concentrated urine. The absorption of water which is within the descending limb leads to an increasing osmotic gradient within the tubule and is also known as the countercurrent multiple systems, which are responsible for maintaining the osmotic medullary gradient in the outer medullary tissue. The thick descending limb of the Loop of Henle expresses a sodium-potassium-chloride cotransporter and this helps to reabsorb approximately one-third of the filtered sodium and chloride from the fluid in the tubular lumen into the blood.

Functions of the Loop of Henle include:

1. Homeostatic mechanisms which help to regulate the extracellular fluid volume

2. Loop of Henle helps in regulating the potassium, calcium and magnesium excretion at the lowest energy costs, and

3. It also helps to regulate the composition of the urinary protein.

Role of Ascending Loop of Henle

The ascending loop of Henle function is impermeable to water. In this, sodium chloride is transported from a thick portion of the ascending limb without accompanying water so an osmotic gradient of approximately 200 mosm/kg is generated. Active sodium transport is accomplished by Na+, K+ -ATPase located in the basolateral membranes of the tubular cells.

Role of the Descending Loop of Henle

The descending limb is highly permeable to water and the reabsorption occurs via AQPI channels. During this process, low amounts of urea  Na+ and other ions are reabsorbed.

Functions of Nephron

The primary function of Nephron is to flush out waste products which include solid waste and other excess from the blood. This blood is converted into urine, secretion and excretion.

Nephron, which is a basic structural unit of the kidney, is in the form of a microscopic structure composed of a renal corpuscle and renal tubule.

The cell present in each tube absorbs different molecules, excluding glucose and beneficial molecules. The blood surrounding the Nephron travels back to the body through renal blood vessels free from toxins.