1. [Outer cortex, inner medulla, and renal pelvis]
Kidney Structure
[Outer cortex, inner medulla, and renal pelvis]
Cortex contains NEPHRON filtering units.
Nephron = Bowman's capsule containing Glomerulus (capillary bed) ---> tubules of nephron.

2. Kidney Structure
Bowman's capsule --> proximal convoluted tubule --> Loop of Henle --> distal convoluted tubule --> collecting duct -->
The urine then drains down the ureter --> urinary bladder (storage area). Passes out of the body through the urethra.
Note: There are thousands of nephrons in each kidney.

3. Make note of location
of Cortex & Medulla- now
locate the Nephron in relation
to these 2 structures

4. Nephron Function Bowman's capsule:
blood enters under very high pressure
arrives directly from the aorta
blood forced into glomerulus & Water, salts, glucose, urea, & amino acids forced out into the nephron - forms crude filtrate.
Up to 95% water & salts resorbed.

5. Nephron Function B) filtrate travels to the proximal convoluted tubule
majority water & salt resorption occurs
water moves from tubule to blood via steep
osmotic gradient
sodium/potassium exchange pump brings sodium back in
glucose & chlorine ions resorbed.

6. Nephron Function C) filtrate moves to the Loop of Henle
Descending part of the loop --> water flows out of the
filtrate [thus concentrating filtrate, by absorbing water back
into circulatory system] --> medulla tissue becomes more
salty
salty medulla --> causes a lot of water absorbed by adjacent
capillaries.
Ascending loop --> sodium pumped out (keeps medulla
salty) --> water leaves descending loop.
Note: much of the sodium is absorbed by the descending part, through a countercurrent exchange of salt.

7. Nephron Function D) Distal convoluted tubule:
sodium & chlorine ions actively transported out
water "follows" and is resorbed by cappilaries of
juxtaglomerular complex.
Tubular secretion formed:
Ammonia, urea, H+ ions pass out of tubule as waste products contained within the filtrate.
Note: ammonia is by product of protein digestion

8. Nephron Function E) Collecting tubule:
sodium ions & water move out of filtrate
other wastes move in
countercurrent exchange of urea
final filtrate forms in duct = URINE

9. 4 5 2 1
Use numbers
To trace flow of
Filtrate through
nephron. 3
Detail of Nephron structure

10. Read: Step by step process of filtration of blood brought to nephron

11. Control of Nephron Function
Antidiuretic Hormone (ADH): controls water absorbtion
Recall, main function of nephron is to help maintain osmotic
balance of your body
Hypothalamus --> signals posterior pituitary to release
ADH when dehydration detected [e.g if
you eat too much salt] .
ADH --> targets cells within collecting ducts
Function: increases cellular permeability to water.
As more water is resorbed, the osmolarity of the blood returns to "normal" and the hypothalamus switches off the production of ADH (Negative Feedback Loop).