1. Kidney Physiology (pg 4)

2. Macroscopic Structure of the Kidney
• Cortex: Outer region

3. Macroscopic Structure of the Kidney
• Cortex: Outer region
• Medulla: Inner region

4. Macroscopic Structure of the Kidney
• Cortex: Outer region
• Medulla: Inner region
• Renal pelvis: large cavity that collects the
urine as it is produced. Continuous with ureter

5. Nephrons
• Nephrons are the functional unit of the kidney

6. Nephrons
• Nephrons are the functional unit of the kidney
• Over 1 million nephrons per kidney

7. Nephron Structure
Nephrons have two parts:

8. Nephron Structure
Nephrons have two parts:
1. Renal corpuscle
a. Glomerulus: cluster of capillaries

9. Nephron Structure
Nephrons have two parts:
1. Renal corpuscle
a. Glomerulus: cluster of capillaries
b. Glomerular (Bowman’s) Capsule: cup that
surrounds the glomerulus and receives
blood filtrate from it

10. 2. Renal tubule
a. Proximal convoluted tubule: Highly coiled.
Located in cortex

11. 2. Renal tubule
a. Proximal convoluted tubule: Highly coiled.
Located in cortex
b. Loop of Henle: A hairpin loop that dips into
the medulla, makes a U-turn, and ascends
back to the cortex

12. 2. Renal tubule
a. Proximal convoluted tubule: Highly coiled.
Located in cortex
b. Loop of Henle: A hairpin loop that dips into
the medulla, makes a U-turn, and ascends
back to the cortex
c. Distal convoluted tubule: Coiled, in cortex

13. Urine Formation
• Nephrons form urine in 3 steps
1. Filtration: Water and small solutes enter the
nephron (blood cells and proteins do not
enter). Filtrate is similar to blood plasma.

14. Urine Formation
• Nephrons form urine in 3 steps
1. Filtration: Water and small solutes enter the
nephron (blood cells and proteins do not
enter). Filtrate is similar to blood plasma.
2. Reabsorption: Useful substances (water,
glucose, amino acids, needed ions) are
transported out of the filtrate and back into
the blood

15. Urine Formation
• Nephrons form urine in 3 steps
1. Filtration: Water and small solutes enter the
nephron (blood cells and proteins do not enter).
Filtrate is similar to blood plasma.
2. Reabsorption: Useful substances (water,
glucose, amino acids, needed ions) are
transported out of the filtrate and back into the
blood
3. Secretion: Harmful substances (H+, excess K+,
some drugs and poisons) are removed from the
blood and put into the filtrate

16. Output (pg 5)
• Color code nephron diagram

17. Hormonal Control
• Hormones regulate the reabsorption of water
and electrolytes by the kidneys

18. Hormonal Control
• Hormones regulate the reabsorption of water
and electrolytes by the kidneys
• If blood volume drops, the pituitary gland
releases antidiuretic hormone (ADH)

19. Hormonal Control
• Hormones regulate the reabsorption of water
and electrolytes by the kidneys
• If blood volume drops, the pituitary gland
releases antidiuretic hormone (ADH)
• ADH causes the kidney duct cells to reabsorb
more water and produce less urine

20. Hormonal Control
• Hormones regulate the reabsorption of water
and electrolytes by the kidneys
• If blood volume drops, the pituitary gland
releases antidiuretic hormone (ADH)
• ADH causes the kidney duct cells to reabsorb
more water and produce less urine
• Alcohol inhibits ADH production

21. Hormonal Control
• Hormones regulate the reabsorption of water
and electrolytes by the kidneys
• If blood volume drops, the pituitary gland
releases antidiuretic hormone (ADH)
• ADH causes the kidney duct cells to reabsorb
more water and produce less urine
• Alcohol inhibits ADH production
• Inability to produce ADH is called diabetes
insipidus (water diabetes). Affected individuals
produce up to 25 liters of very dilute urine per
day and are constantly thirsty