Hormones & Diseases

Reabsorption

CONDITIONS THAT CAUSE MORE WATER TO BE REABSORBED:

CONDITIONS THAT CAUSE MORE WATER TO BE EXCRETED:

Too Much Water Intake
Diuretics (like Coffee, Alcohol, etc.)
- Diuretics cause our tubular membrane to become less permeable to water and this prevent water from being reabsorbed back into the blood and rather leaves it to be excreted in our urine.
  - Hypertonic Urine: More salt than water in urine
  - Hypotonic Urine: More water than salt in the urine.

In the kidney hormones regulate all functions
As conditions in our internal environment change the composition, volume and osmolarity of water is adjusted
- More salt intake means less water intake and this equals more water to be reabsorbed.
- Less salt intake means more water intake and this equals less water reabsorption and diluted urine that has high water concentrations and low salt concentration.

The Antidiuretic Hormone (ADH) is produced in the Hypothalamus and stored/released by the Pituitary Glands in the brain.
Osmoreceptors in the hypothalamus detect and monitor the osmolarity (water-salt concentration) of the blood
- When it RISES (ie. loss of water due to sweating) MORE ADH is released into the blood so it can reach the kidney.
ADH targets the Distal Convoluted Tubule and Collecting Duct in the nephron and makes them more permeable to water.
- This reduces the amount of water in our urine and also decreases the urine volume to help increase blood osmolarity.
When there is a LARGE consumption of water then LITTLE ADH is released
- ADH is called the antidiuretic hormone since it opposes diuresis, which is the production of urine, as it reduces the urine volume.

When the blood pressure or blood volume decreases in the AFFERENT ARTERIOLE then an enzyme renin initiates a response where a plasma protein turns into a peptide that begins to act as a hormone.

INCREASED BLOOD PRESSURE:

When arteriole become constricted, to increase blood pressure in the body, Aldosterone will function to narrow these blood vessels so the pressure within them rises.
Aldosterone stimulates the Adrenal Gland to produce Aldosterone, this hormone acts on the Proximal and Distal Convoluted Tubules and increases their permeability to water and salt.
- More water and salt are reabsorbed into the blood to increase blood volume and pressure
  - Less salt and water is excreted in our urine as a result

If the blood volume is high, but the blood salt concentration increases (due to sweating for example) then ADH is released to lower the salt concentration in the blood and to increase its water concentration.

If the blood pressure or volume decreases (due to injury or diarrhea for example) then Aldosterone is released so more water and salt is reabsorbed into the blood (na+ reabsorption and K+ secretion)

KIDNEY DIALYSIS:

Is a technique used to remove waste and excess fluid from the body
Treatment for kidney failure where one must be hooked up to a machine for several hours a day that helps function like a kidney and regulates waste, nutrients and water to maintain your blood volume, pH and composition.

KIDNEY TRANSPLANT:

Done when one reaches the end stage of kidney failure, which can be caused by high blood pressure or diabetic problems.
Recipient must be genetically similar to the donor in order for this procedure to be successful with little to no chance of rejection or failure.
To perform the procedure an incision is made in the lower right abdomen.
- Iliac vessels and the ureter are connected to and from the kidney
- o kidney is removed, but rather a third kidney is just attached to the vessels that run to the second kidney. This is done to lower the risk of rejection so they procedure is successful.

Kidney stones are hard stone-like objects that are created from calcium salts and other ions
High calcium and salt diets and low water intake results in the creation of kidney stones.
They form in the renal pelvis and can block the ureter
However, they can be broken using high frequency sound waves, but te removal processes is very painful as these broken down stones must still pass through your urinary system to get out.

PREVENTION OF URINARY DISEASES:

CONTROL HYPERTENSION: Which ultimately means keep your blood pressure low to reduce the stress on the blood vessels in the kidney.
CONTROL DIABETES: High glucose levels cause high blood pressure and can damage the glomerulus capillaries.
CONTROL WEIGHT: This increases the risk of diabetes and high blood pressure so it's good to keep your weight low and normal according to your height, mass and gender.