Table of Contents
What are the responsibilities of nephron loops in Juxtamedullary nephrons?
The long nephron loops of juxtamedullary nephrons first concentrate and then dilute the filtrate. In the descending limb, water is reabsorbed as it moves down its osmotic gradient and concentrates the filtrate. In the ascending limb, solutes (Na+ and Cl−) are actively pumped out and reabsorbed.
What is the purpose of the long loop of the nephron?
This part of the nephron is called the loop of Henle. Its main function is to reabsorb water and sodium chloride from the filtrate. This conserves water for the organism, producing highly concentrated urine.
Why do Juxtamedullary nephrons produce concentrated urine?
Although both cortical and juxtamedullary nephrons regulate the concentrations of solutes and water in the blood, countercurrent multiplication in the loops of Henle of juxtamedullary nephrons is largely responsible for developing the osmotic gradients that are needed to concentrate urine.
How does the length of the loop of Henle impact urine concentration?
Average lengths of loops of Henle are not directly proportional to urine concentration when comparing large with small species of mammals. The relative thickness of the medulla is related to urine-concentrating ability because the medulla contains the loops of Henle.
Which is responsible for production of concentrated urine?
The renal medulla produces concentrated urine through the generation of an osmotic gradient extending from the cortico-medullary boundary to the inner medullary tip.
What causes more concentrated urine?
Increased urine concentration may be due to different conditions, such as: Heart failure. Loss of body fluids (dehydration) from diarrhea or excessive sweating. Narrowing of the kidney artery (renal arterial stenosis)
What conditions cause urine to become concentrated?
If your urine is very concentrated, your doctor may suspect one or more of the following conditions:
- dehydration.
- diarrhea.
- excess sweating.
- glycosuria (too much sugar in your urine)
- heart failure.
- narrowing of the renal arteries.
- inappropriate ADH secretion.
- excess vomiting.
Why do we urinate more in wet and cold months?
During the Cold and the wet seasons, the amount of sweat produced by our bodies to keep us cool decreases greatly. This means that we are no longer losing water through sweat. This excess water has to be filtered out in some other way. Which is why the amount of urine produced goes up quite a bit.
Why does the juxtamedullary nephron concentrate and dilute urine?
The juxtamedullary nephrons concentrate or dilute urine. As a result of the short loop of Henle, the vasa recta of the cortical nephrons is small. The long loop of Henle of the juxtamedullary nephrons is surrounded by a large vasa recta network.
Where does the loop of Henle of the cortical nephron extend?
The loop of Henle of the cortical nephron extends only to the outer renal medulla while that of the juxtamedullary nephron extends to the deeper of the renal medulla. Cortical nephrons are mainly involved in the excretory and regulatory functions of the body while juxtamedullary nephrons concentrate or dilute urine.
Which is the final filtrate of a cortical nephron?
Since the loop of Henle is short, the vasa recta is also small in the cortical nephrons. The final filtrate of a nephron is called the urine. Juxtamedullary nephron refers to nephrons whose loop of Henle extend deep into the renal medulla.
Which is more susceptible to blood pressure cortical or juxtamedullary nephrons?
Cortical nephrons account for about 80% of all the kidneys’ total filtration capacity and are more susceptible to damage from high blood pressure than juxtamedullary nephrons. Because they filter such large amounts of blood, cortical nephrons are also sometimes referred to as “major” nephrons.