Title: The Renal Tubule: Definition, Function & Terms - Video & Lesson Transcript | Study.com
Headings: The Renal Tubule: Definition, Function & Terms
The Renal Tubule: Definition, Function & Terms
The Ultrafiltrate in the Renal Tubule
Proximal Convoluted Tubule
The Loop of Henle
Distal Convoluted Tubule and Connecting Tubule
The Role of PTH in the Regulation of Calcium
Register to view this lesson
Are you a student or a teacher?
The Renal Tubule: Definition, Function & Terms
Related Study Materials

Content: This difference in functionality is what establishes the kidney's medullary osmotic gradient for maximal conservation of water. Distal Convoluted Tubule and Connecting Tubule
Once the filtrate passes through the thick ascending limb of Henle, it enters the distal convoluted tubule, which is a duct of the renal tubule located in the kidney's cortex that reabsorbs calcium, sodium, and chloride and regulates the pH of urine by secreting protons and absorbing bicarbonate. The reason this is called the distal, as opposed to proximal, convoluted tubule is because it is the segment farthest away in terms of position and connection to the renal corpuscle. The distal convoluted tubule will then connect to a section called the connecting tubule, which will do many of the same things as the distal convoluted tubule, but it is not, however, considered to be a part of the renal tubule. The Role of PTH in the Regulation of Calcium
It's important to know that a hormone in your body, called parathyroid hormone, or PTH for short, plays a role in the distal and proximal convoluted tubules. Recall that the majority of calcium is reabsorbed, through passive means, in the proximal convoluted tubule. This is the case under normal conditions. However, if PTH is secreted in response to low levels of calcium in the blood, then the proximal convoluted tubule will not be allowed to reabsorb calcium. Instead, the majority of calcium will be reabsorbed actively in the distal convoluted tubule and connecting segment as well as part of the loop of Henle. In addition, PTH will prevent the proximal tubule from reabsorbing phosphate, causing a net excretion of phosphate out of the body via urine.