1. Urinarysystem

2. Anatomical structure The kidney present in the lower back of t the abdominal wall Adrenal gland kidney ureter Urinary bladder urethra

3. The nephrone Bowman’s capsule and glomerulus

4. The nephrone

5. Nepherone • Its small functional unit, which is equal one million on each kidney. • Its two types: 1) cortical nepheron (85%), responsible for formation of urine 2) medullary nepheron (15%), responsible for concenration of the urine

6. Structure of the nephron the kidney is composed of about 1 million functional units called nephron. one nephrone consist of : 1-glomerular capsule (Bowman”s capsule & glomerulus) 2- the proximal convoluted tubule 3- loop of Henle ( medullary (long) and cortex (short) loop) 4- distal convoluting tubule 5- collecting duct

7. function of cortical nephrone ((Urine formation • Glumerular filtration (movement of the blood from glumorulus toward Bowman’s capsule) • Tubular reabsorption (movement of filtrated fluids from convoluted tubules toward the blood) • Secretion (movement of the blood from the blood capillaries around the tubules toward convoluted tubules) • excretion (movement of filtrated blood from renal tube to outside the body)

8. I- Glumerular filtration • Glumerular filtration is move the fluid (plasma-protein) from glumorulus toward Bowman’s capsule. • Glumerular filtration depends on three pressures. These pressures are: 1) glomerular capillary hydrostatic pressure (60 mmHg) 2) intracapsular pressure (18 mmHg) 3) colloidal pressure (plasma protein pressure) (25mmHg)

9. (Glomerular filtration rate) GFR Definition: its volume of the blood filtrate from the glomeruli into Bowman`s space per unit time. Normal value: in 70Kg person the volume of filtration equal 125ml\min or 180L\day. plasma volume filtrate by the kidney is about 60 times a day

10. II- Tubular reabsorbtion(movement of filtrated fluids from convoluted tubules toward the blood) This process help to maintain fluids and electrolyte balance and blood PH Proximal tubule 1- glucose • all glucose molecules filtrated in Bowman’s capsule are reabsorbed again toward the blood by active transport process. • Tubular maximum absorption for glucose is equal 300mg/ min • Normal amount of glucose in the blood is about 100mg/ 100ml • If the amount of glucose in the blood is more than 180mg/100ml the glucose molecules will appear the urine (glucouria)

11. Proximal tubule 2- protein • Small amount of protein filtrated from Bowman’s capsule (30-50mg\day), but its reabsorbed again in proximal tubule by active transpose process • If the protein molecule not absorbed due to kidney diseases, it will appear in the urine (albuminuria)

12. Proximal tubule 3- water and electrolyte (Na) • 70% of water and Na reabsorbed in proximal tubule by active transport 4- urea • 50% of urea absorbed

13. 20-30% of water and electrolyte absorbed in lube of Henley by diffusion for the water and active transport for electrolyte • (descending lube of Henley is thin and mainly its reabsorbed the water, but ascending lube of Henley is thick and reabsorbed Na and electrolytes)