2.75- Urine

Recall that urine contains water, urea and salts

• Urine contains water, urea and salts
• Salts and urea are removed by Osmoregulation to maintain to isotonic tissue fluid with the cells
• The removal of urea is a part of excretion of metabolic waste 

2.74- ADH

Describe the role of ADH in regulating the water content of the blood


ADH- Anti- Diuretic Hormone

• It is produced in a region of the brain known as the Hypothalamus
• It flows through the blood streams to the kidney
• Its effect is to control and alter the quantity of water in blood
• The tissue fluid should be isotonic with the cells
• ADH targets the collecting duct
• It allows more water to come out of the collecting duct
• ADH makes the collecting duct walls more porous
• Consequences of ADH- urine becomes more concentrated and the volume decreases

2.73- Glucose Re-absorption

Understand that selective reabsorption of glucose occurs at the proximal convoluted tubule


Selective Re-absorption- 

• A molecule is selected and is reabsorbed into the blood
• The molecule is removed from the blood and then it is put back in
• Normally, there is no glucose in urine
• If there is glucose, it could result in the person having diabetes
• In the first convoluted tubule, glucose is removed and reabsorbed into the blood

2.72- Water Re-absorption

Understand that water is reabsorbed into the blood from the collecting duct

• When the ultrafiltration occurs in the Bowman's capsule, too much water is filtered.
• The water is removed from the filtrate
• It is then added into the blood vessels
• This is called selective reabsorption

2.71- Ultrafiltration

Describe ultrafiltration in the Bowman’s capsule and the composition of the glomerular filtrate


The filtration of the blood takes place in the Nephron. There are two products- Filtered blood (clean) and the waste (urine).
The urine (water, salts and urea) drains into the bladder from the pelvic region.

• The blood arrives in the kidney through the Afferent Arteriole
• The Arteriole begins to branch off and create a twisted knot-like structure Glomerulus
• The diameter of the Efferent Arteriole is smaller
• This creates a high pressure
• Plasma (water, salts, amino acids, glucose and urea) forced out of the blood vessel and into the inside of Bowman's capsule
• This is now called the Glomerular filtrate
  

2.70- Nephron Structure

Describe the structure of a nephron, to include Bowman’s capsule and glomerulus, convoluted tubules, loop of Henlé and collecting duct

Nephron-  The functioning part of the kidney, it does the filtration and the controlling of the composition of the blood.
Bowman's capsule- The dead end to the Nephron
Proximal Convoluted tubule- The first twisted section
Distal Convoluted tubule- The second twisted section
Glomerulus- Filters the blood and is surrounded by the Bowman's capsule
Loop of Henlé- Leads the Proximal tubule to the distal tubule
There are millions of Nephrons in the kidney.