

Preview text:
As you know, The urinary system is an organ system that helps the body 
remove excess fluids and dissolved substances from the blood 
circulation to the external environment.
The urinary system consists of the  ,  kidneys ,  ureters , and  bladder the  .  urethra
Firstly, let’s learn about the kidney. In normal human, we have two 
kidneys, 1 on the right and 1 on the left. they are shaped like peas and 
function as a water filtering factory for a city. In addition to filtering the 
blood, the kidneys also help regulate pH, volume, pressure, and control  levels of   and metabolites, horm electrolytes one production
 The kidneys are located between vertebrae T12 and L3 and are partially 
protected by ribs 11 and 12. The right kidney is pushed down by the 
liver, so it is located slightly lower than the left kidney. 
In the middle of each kidney there is an indentation forming the renal 
hilum - this is the entry and exit point of the ureters, renal arteries, renal 
veins, lymphatic vessels, and nerves entering and leaving the kidney.
When we look at the cross section of the kidney, on the outside we will  have the 
. So we've got the outer layer of the kidney and t renal cortex hen on the inside we have the 
 and then on the center we have  renal medulla the  . 
renal pelvis The renal medulla is formed from 10-18    renal pyramids
with the base of the pyramid facing the renal cortex, the top of the  pyramid (the  ) towards the center of t renal papilla he kidney. Renal  papilla towards the  , the minor calyces m minor calyces erge into the 
major calyces to form a funnel towards the renal pelvis. 
The nephron is the structural unit of the kidney. There are about 1 
million nephrons in each kidney. Each nephron is made up of renal  corpuscles and  . 
renal tubules The renal corpuscle is where blood 
filtration begins, it consists of the   - very small capillar glomerulus y 
networks - and the bowman's capsule. 
When blood flows into the glomeruli, water and some solutes such as 
sodium will go to the bowman's capsule and become filtrate (also be 
called the first unrine.) The first urine after being filtered in the 
glomerulus is still rich in nutrients, so it will be reabsorbed in the renal  tubules.  Renal tubule consists of  , the  proximal convoluted tubule loop of henle,  distal convoluted tubule  conllection duct and  . 
Here will occur the process of reabsorption and excretion of some 
substances to turn the filtrate into urine. 
 On average, about 170-180 liters of first urine are produced every day, 
but after reabsorption, only about 1-2 liters of urine are actually formed.
 Millions of urine-forming nephrons flow into the minor calyces, then to 
the major calyces, and finally into the renal pelvis. From there it goes 
down the ureter and is stored in the bladder. 
In the kidney, some substances are reabsorbed back into the blood, the 
rest are filtered and taken to the bladder to be excreted.
The kidneys of an adult filter about 150 liters of blood per day. If the 
blood in the body is assumed to be 5 liters, the entire blood volume will 
be filtered 30 times per day. The kidneys thus receive about a quarter of  the   output. cardiac