1. Urine Formation

2. Review of nephron structure

3. The Nephron glomerulus proximal convoluted tubule efferent arteriole
blood
distal convoluted tubule
blood
afferent arteriole
Loop of Henle

4. The Nephron
- Most components of the nephron are within the cortex.

5. Review of Nephron Structure

6. Glomerulus Structure

7. Normal URINE 95% water Urea Uric acid Amino acids (trace)
Electrolytes (NA, K, H, Cl)
Urochrome =yellow pigment
Kidney filter 180 L/Day
Urine

8. Abnormal URINE RBCs- popped vein or artery in kidney
WBCs- indicate infection
Glucose- lack of insulin to move glucose into muscle
Increased amt. of proteins- serious problem
Crystals/kidney stones- calcification, formed in renal pelvis
Ketones- poorly controlled diabetes, starvation
Microbes
drugs

10. Steps to Urine Formation
1. Glomerular filtration- water and other dissolved substances are filtered out of blood and into glomerular capsule Filtrate- liquid filtered out of capillaries and passes through nephron

11. Tubular reabsorption and Tubular secretion

12. Steps to Urine Formation
2. Tubular Reabsorption- taking needed substances from the filtrate and transferring them back into the blood
Occurs in PCT, LOH, DCT
Passes substances from tube to blood via osmosis and active transport
Reabsorbs water, glucose, amino acids, electrolytes, urea, uric acid, protein

14. Steps to Urine Formation
3. Tubular Secretion- substances move from blood into the nephron and enter filtrate, larger substances
Occurs in PCT, LOH, DCT
Wastes
electrolytes
water
drugs
H ions, penicillin, ammonia, K
Happens faster than filtration

15. Tubular reabsorption and Tubular secretion

16. Control of Urine Formation
At the same time as tubular absorption takes place in the PCT, tubular excretion is also occurring in the DCT.

18. Checkpoint
On your notes, write the pathway that filtrate/urine takes from the blood and out of your body.

19. Path of Urine Glomerulus PCT Nephron loop (LOH) descending limb
Nephron Loop (LOH) ascending limb
DCT
Collecting duct
Renal Papilla
Minor calyx
Major calyx
Renal pelvis
Ureter
Urinary bladder
urethra

20. Factors that can affect the filtration rate
1. Diameter of the arterioles (both afferent and efferent) 2. Permeability of the membrane of the glomerulus 3. Obstruction of the flow of urine.