Lets learn about the anatomy of the urinary system.
The urinary system consists of the kidneys, ureters, urinary bladder and urethra.
The kidneys are located behind the peritoneal membrane of the abdomen and extend from about
T12 to L3.
Lets take a closer look at the kidneys.
Each kidney is surrounded by a tough fibrous outer layer called the renal capsule.
The outer portion of the kidney is called the cortex.
The inner portion is called the medulla.
The medulla contains large structures called pyramids.
This is where urine formation occurs.
Renal columns are located between the pyramids they contain the same tissue as the cortex
Each pyramid ends in a renal papilla.
Urine drains from the renal papillae to the minor calyces.
The minor calyces combine to form major calyces which combine to form the renal pelvis.
Urine drains from the renal pelvis to the ureter.
The area where the ureter exits the kidney and the renal artery and vein enter is called
the hilum.
The kidney is filled with microscopic structures called nephrons.
There are cortical nephrons and juxtamedullary nephrons which extend deep into the medulla.
Here are the parts of a nephron.
The glomerulus is a capillary tuft that filters blood.
It is surrounded by a fibrous capsule called the glomerular capsule or Bowmans capsule.
The afferent arteriole carries blood into the glomerulus while the efferent arteriole
carries blood out.
The glomerulus filters the blood and the filtrate flows through the proximal convoluted tubule.
Urine flows to the nephron loop or loop of Henle.
Urine flows from the nephron loop to the distal convoluted tubule.
From there it flows to the collecting duct which drains into the renal papilla.
The nephron is surrounded by peritubular capillaries.
Capillaries surrounding the nephron loop are called vasa recta.
The ureters carry urine to the urinary bladder.
The area between the ureter connections to the bladder and the urethra is called the
trigone area.
An area of smooth muscle called the detrusor muscle surrounds the bladder.
The urethra carries urine out of the body.
Males have an internal urinary sphincter muscle which shuts off urine flow during sexual arousal.
Both males and females have external urinary sphincter muscles which relax when urinating.
We hope you have learned something about urinary anatomy and see you next time.