Nefrona partes y funcionamiento | Epitelios del túbulo contorneado proximal, asa de la nefrona y mas
Understanding the Structure and Function of Nephrons
Introduction to Nephrons
- The video welcomes viewers and introduces the topic of nephron physiology, emphasizing its fascinating functions.
- Each segment of the nephron has a unique epithelial structure, with specific cells performing distinct functions related to membrane surface area, mitochondria presence, enzymes, and central cilia.
Epithelial Types in Nephrons
- The glomerular capsule's epithelium transitions into the tubular system at the urinary pole, forming a continuous tube that connects to a collecting duct.
- This tubular structure features a lumen (or tubular space) where filtered liquid flows; each region has specialized epithelium for substance absorption and secretion necessary for urine formation.
Proximal Tubule Characteristics
- The first segment after the glomerular capsule is the proximal convoluted tubule (PCT), which has numerous curvatures close to the capsule.
- PCT epithelial cells are simple cuboidal with brush borders (microvilli), enhancing contact with filtrate. They also contain abundant mitochondria and significant central cilia for function optimization.
Structural Divisions of Proximal Tubule
- The proximal tubule can be divided into convoluted and straight sections or further segmented based on ultra-structural characteristics.
Loop of Henle: Structure and Function
- Following the PCT is the nephron loop (Loop of Henle), which consists of descending thin limbs, ascending thin limbs, and thick ascending limbs.
- The descending and ascending thin segments have simple squamous epithelium with few mitochondria; in contrast, thick ascending limbs feature simple cuboidal epithelium with more mitochondria.
Distal Tubule Overview
- The distal convoluted tubule (DCT), located at the end of this segment, contains simple cuboidal epithelial cells rich in mitochondria.
- DCT connects to principal cells and intercalated cells—both types differ structurally and functionally but share mitochondrial abundance.