2.75 Urine

1. Urine contains water, urea and salts.

2. The role of the brain influences the function of the kidneys through ADH

4. After the urine goes down the collecting duct, it goes into the bladder.

5. Salts and H2o effects the composition of the tissue fluid.

6. The removal of the urea is done through the excretion of metabolic waste.

2.74 ADH

1. ADH helps regulate the water content of blood.

2. The hormone is produced in the hypothalamus part of the brain. It flows through the blood stream and targets the kidney

3. The effect of the hormone is to control and alter the composition/quantity of water that is in blood. It has the ability to make the blood more or less concentrated.

4. Important when keeping the cells isotonic the the tissue around it.

5. ADH targets the collecting duct. It allows more water to come out of the collecting duct. The hormone makes the amount of water coming out increase

6. The water then goes into the blood stream

7. The consequence is that the urine coming out is more concentrated and it has a lower volume.

2.73 Glucose re-absorbiton

1. Happens in the PCT

2. The glucose is firstly selected

3. The glucose is taken and then put back into the blood stream.

4. In the PCT, glucose is removed and is taken back into the blood stream

5. This means that there is no glucose in urine.

2.72 Water re - absorption

1. Glomerular filtrate excrete too much water out of the collecting duct.

2. As the filtrate passes through, the water is removed from the filtrate.

3. The water is then taken back into the blood stream.

4. This is called selective reabsorption

2.71 Ultrafiltration

1. Nephron - carries out the filtration of the blood. Giving us 'clean' blood and waste. (urine)

2. Urine is largely composed of water, salts and Urea which contains the nitrogen waste.

3. The urine goes down the collecting duct and then through the pelvic and then out of the ureter.

4. Bowman's Capsule - the site of ultrafiltration

Bowman's capsule and the filtration of blood

1. Blood goes into the bowman's capsule from an artery - (high BP)

2. The bowman's capsule branches into a smaller ball of blood vessels. (the glomerular)

3. When the blood flows down the vessels, because the diameter is smaller, they gain pressure, making the blood come out with a higher blood pressure.

4. The consequence of this is that the high blood pressure forces the liquid within blood - plasma (H2O, Salts, Amino Acids, glucose and urea) to release all these substances into the inside of the bowman's capsule.

5. The substances in the plasma and the plasma itself get taken into the bowman's capsule, the name changes to glomerular filtrate

2.70 Nephron Structure

1. The aorta branches off into the renal artery and then goes into the kidney.

2.The kidney then filters the blood and the urine goes down the ureter. This then follows into the bladder.

3. The filtered blood then goes on and back into the renal vein.

4. The kidney has 3 different parts to it. the outside layer, the cortex, the middle layer, the medulla and the inner area, the pelvic.

5. In the pelvic, it collects the urine and drains it down the ureter

6. The different sections are there because the kidney is made up of millions of different tubular structures.

7. The tube starts at the pelvic and runs through the medulla in a mountain like pattern, then the tube goes into the cortex, where it is stopped. The end is called the bowman's capsule.

8. The tube is called the nephron

The Nephron

1.Mainly in the cortex, but dips into the medulla for the collecting duct and the loop of henle

2. 1st twisted section is called the proximal convoluted tubule, the second is called the distal convoluted tubule.

3.There are millions of Nephrons in the kidney.