Name the six main areas of the nephron...
- bowman's capsule - glomerulus
- collecting duct
- blood capillaries
- convoluted tubules
- loop of henle
Summarise the process of the nephron in three points...
- filtration: lots of water, ions, urea and sugar are squeezed from the blood into the tubules
- selective reabsorption: ions and sugars are reabsorbed back into the blood from the tubules and the amount of water in the blood is regulated at a constant rate
- excretion of waste: urea, excess water and ions travel to the bladder as urine
What is osmoregulation?
It is the regulation of water in the blood in the kidneys, keeping it at a constant rate
What hormone controls the kidneys and the concentration of urine within them?
- ADH (anti-diuretic hormone)
- this is produced by the pituitary gland
If water concentration in the kidneys falls, what happens?
- more ADH is produced
- the kidney absorbs more water
- a small volume of very concentrated urine is produced, reducing water loss
If water concentration in the kidneys rises, what happens?
- less ADH is produced
- the kidney absorbs less water
- a large volume of very dilute urine is produced
- this increases water loss
What is meant by the term 'negative feedback mechanism'?
When a substance is produced in our bodies to return a system to normal
How is ADH an example of a negative feedback mechanism?
ADH is produced in response to low blood water levels
What is the darker outer region of the kidney called?
What does the cortex contain?
- tiny blood vessels that branch off from the renal artery
- microscopic tubes and filtering units known as kidney tubules or nephrons