1. The Interaction Between the Urinary System, the Endocrine System, and the Nervous System

2. Anyone Thirsty?
The sensation of thirst and your body’s ability to maintain a proper water balance are controlled by the communication between the
nervous system
the endocrine system
the urinary system

3. Regulation of Salt and Water
Hypothalamus
Senses via osmoreceptors that the salt content within the body is either to high or too low.
High Levels
Due to sweating/loss of water
Stimulates posterior lobe of pituitary to release Anit- diuretic hormone (inhibits urine formation)
ADH travels via blood to kidneys
Causes the tubules to be more permeable to water (reabsorption into blood)
This causes less urine output

4. Example Think of a hot summer day
Your out working, sweating, not drinking a whole lot.
You don’t realize it, but you really don’t pee a lot.
Your body is trying to keep as much water as possible.

5. Regulation of Salt and Water
Hypothalamus
Senses via osmoreceptors that the salt content within the body is either to high or too low.
Low Levels
Posterior lobe of pituitary DOES NOT release Anit-diuretic hormone
Causes the tubules to be LESS permeable to water (little to no reabsorption into blood)
This causes MORE urine output

6. What Does the Adrenal Glands Have to do With Urine?
Has two parts
Medulla
Cortex
Has three different regions secreting different types of steroids

7. Adrenal Cortex
Glucocorticoids are secreted by the middle region of the adrenal cortex.
The principal glucocorticoid is cortisol
helps maintain blood pressure and cardiovascular function
helps balance the effects of insulin in breaking down sugar for energy
helps regulate the metabolism of proteins, carbohydrates, and fats
helps maintain proper arousal and sense of well- being

8. Adrenal Cortex
Another group of steroids secreted by the adrenal cortex is the gonadocorticoids, or sex hormones.
These are secreted by the innermost region.
Male hormones, androgens, and female hormones, estrogens, are secreted in minimal amounts in both sexes.

9. Adrenal Cortex Last group secreted is the Mineralocorticoids
Mineralocorticoids are secreted by the outermost region of the adrenal cortex.
The principal mineralocorticoid is aldosterone, which helps maintain blood pressure and the balance of water and salt in the body by helping the kidney retain sodium and excrete potassium.
How does this work?

10. Aldosterone and K+
Acts to maintain the homeostasis of sodium and potassium ions.
It causes the kidneys to conserve sodium ions (Na+) and to excrete potassium ions (K+).
At the same time, it promotes water conservation and reduces urine output.

11. Aldosterone and K+
As K+ levels increase within the body, receptors on the adrenal cortex are stimulated.
This causes the adrenal cortex to release aldosterone into the blood.
The blood travels through the kidneys
The aldosterone inhibits the absorption of K+ back into the blood stream = more excreted in the urine

12. Aldosterone and Na+
The Adrenal Cortex is also sensitive to sodium as well.
Levels are low = aldosterone is released to prevent Na + from being excreted in the urine.
We have TWO mechanisms in place to prevent excess loss of sodium. Why is sodium so important in the body that we have TWO mechanisms to prevent its loss?

13. Nerve Impulses!

14. Aldosterone and Water
The Adrenal Cortex is also sensitive to levels of water.
Levels are low = aldosterone is released to prevent water from being excreted in the urine.
Again…what are TWO mechanisms the body uses to conserve water?

15. Aldosterone
Antidiuretic Hormone

16. Drugs that Change Urination
Diuretics
Promote the loss of water
Some prevent water reabsorption along the tubules
Can be dangerous because they cause you to excrete a lot of water along with sodium and potassium
Used for edema
Build up of fluid = maybe heart failure
Some block sodium and chloride transport
Helps accelerate the loss of sodium in fluid to reduce blood pressure (hypertension – high blood pressure)