The urinary system functions to excrete waste from the body and regulate fluid balance, electrolytes, and acid-base levels. It consists of two kidneys, two ureters, a urinary bladder, and a urethra. The kidneys filter blood to form urine and are located retroperitoneally in the abdominal cavity. They contain microscopic filtration units called nephrons that filter blood to form urine, which travels through the ureters to the bladder and then exits through the urethra. Hormones regulate fluid balance and the reabsorption of water and electrolytes during urine formation.

1. Genitourinary system

2. Functions of urinary system
 Excretions of metabolic waste products
 Regulation of body fluid volume and osmolality
 Regulation of electrolytes
 Regulation of acid-base balance
 Regulation of acid-base balance
 Production of erythropoietin, 1,25-
dihydroxycholecalciferol, renin and prostaglandins
 Metabolism of hormones

3. Parts of urinary system
Two kidneys
Two ureters
Urinary bladder
Urethra

4. Kidneys
Position- Situated
on the posterior
abdominal wall,
retroperitoneally.
 Bean shaped
 7.5-10cm length,
5cm width and
2.5cm thick
 Wt- 150gm

5. Organs associated with Kidney

6. Left kidney
1. Anteriorly- Spleen, splenic
vessels, jejunum, pancreas
and stomach.
2. Posteriorly- Diaphragm and
muscles of posterior
abdominal wall, pancreas and
stomach
3. Superiorly- left adrenal
gland
Right kidney
1. Anteriorly-Duodenum,
hepatic flexure of colon,
Rt lobe of liver
2. Posteriorly- Diaphragm,
muscles of posterior
abdominal wall,
subcostal vessels and
nerves
3. Superiorly- Rt adrenal
gland

7. Covering of kidney

8. Gross structure of kidney

9. Microscopic structure of kidney- Nephrons

10. Functions of different parts of nephron

11. Path of urine

12. Blood supply to the kidney

13. Physiology of urine formation
Glomerular filtration
Tubular reabsorption
Tubular secretion

16. Calcitonin- Decreases calcium reabsorption
Angiotensin II- Increases sodium reabsorption
in proximal tubule, thick ascending limb,
distal tubule and collecting duct.

17. Ureters

18. Urinary bladder and
urethra