The Kidneys And The Excretory System - Part 3 (T2) Flashcards
1
Q
Name the six main areas of the nephron…
A
- bowman’s capsule - glomerulus
- collecting duct
- blood capillaries
- convoluted tubules
- loop of henle
2
Q
Summarise the process of the nephron in three points…
A
- 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
3
Q
What is osmoregulation?
A
It is the regulation of water in the blood in the kidneys, keeping it at a constant rate
4
Q
What hormone controls the kidneys and the concentration of urine within them?
A
- ADH (anti-diuretic hormone)
- this is produced by the pituitary gland
5
Q
If water concentration in the kidneys falls, what happens?
A
- more ADH is produced
- the kidney absorbs more water
- a small volume of very concentrated urine is produced, reducing water loss
6
Q
If water concentration in the kidneys rises, what happens?
A
- less ADH is produced
- the kidney absorbs less water
- a large volume of very dilute urine is produced
- this increases water loss
7
Q
What is meant by the term ‘negative feedback mechanism’?
A
When a substance is produced in our bodies to return a system to normal
8
Q
How is ADH an example of a negative feedback mechanism?
A
ADH is produced in response to low blood water levels
9
Q
What is the darker outer region of the kidney called?
A
The cortex
10
Q
What does the cortex contain?
A
- tiny blood vessels that branch off from the renal artery
- microscopic tubes and filtering units known as kidney tubules or nephrons
