Anatomía del sistema renal - Parte 1
Human Urinary System Overview
Structure and Function of the Human Urinary System
- The human urinary system is located between the peritoneum and the dorsal bones and muscles, consisting of two kidneys, two ureters, a bladder, and a urethra. These components work together to produce urine from an initial plasma filtration process through reabsorption and secretion.
- Urine travels to the bladder via the ureters, where it is temporarily stored until eliminated through the urethra.
Anatomy of the Kidneys
- The kidneys are reddish-brown organs symmetrically positioned on either side of the spine at the level of the 10th and 11th ribs; typically, the left kidney is higher than the right. They account for approximately 0.5% of total body weight and have a bean-like shape.
- Each kidney is covered by a fibrous tissue capsule; internally, there are two regions: cortex (outer) and medulla (inner). The medulla consists of several renal pyramids that drain into calyces leading to renal pelvis.
Nephron Structure
- The functional unit of each kidney is called a nephron, with about 1.5 million nephrons in each human kidney. Each nephron includes a filtering component known as Bowman's capsule along with a tubular system responsible for secretion and reabsorption processes that determine final urine composition.
- Bowman's capsule contains glomeruli (capillary networks) receiving blood from afferent arterioles branching from renal arteries; filtered liquid enters Bowman's space before moving into renal tubules for further processing.
Renal Tubule Segments
- Following Bowman's capsule are various segments: proximal tubule (longest), loop of Henle (with descending/ascending limbs), distal tubule, and collecting duct shared among multiple nephrons which empties into calyces in renal pelvis. Each segment has distinct epithelial cell structures crucial for its function.
- Proximal tubule features numerous spirals; loop of Henle's descending limb leads to an ascending limb that parallels it before connecting to distal tubule followed by collecting duct systems that manage urine concentration levels effectively.
Juxtaglomerular Apparatus