Excrerion - The Kidneys Flashcards Preview

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Flashcards in Excrerion - The Kidneys Deck (11)
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1
Q

What are the kidneys?

A

Excretion organs part or the urinary system

2
Q

What are the three main roles of the kidney?

A
  • Removal of urea from the blood
  • Adjustment of salt levels in the blood
  • Adjustment of water content in the blood
3
Q

Where and why is urea produced?

A
  • In the liver due to excess amino acids
4
Q

How do the kidneys preform the three roles?

A

They filter stuff out of the body at high pressure and then reabsorb the useful things - the end product is urine

5
Q

What are nephrons?

A

Filtration units in the kidneys - the kidneys contain thousands of nephrons

6
Q

What three steps take place in the nephron?

A
  • Ultrafiltration
  • Réabsorption
  • Release of wastes
7
Q

What happens in ultrafiltration?

A
  • Blood from renal artery flows through the glomerulus
  • High pressure is built up which squeezes water, urea, salts and glucose out of the blood into Bowmans Capsule
  • Membranes in the glomerulus act like filters so bog molecules like proteins are not squeezed out and say on the blood
8
Q

What is the filtered liquid in the Bowmans Capsule called?

A

Glomerular filtrate

9
Q

What happens in reabsorption?

A

Useful substances are selectively reabsorbed

10
Q

Name the three things that are reabsorbed back into the blood?

A
  • All glucose from proximal convoluted tubule by active transport
  • Sufficient salt (excess isnt)
  • Sufficient water from collecting duct to bloodstream
11
Q

What happens in the release of wastes?

A
  • Remaining substances (water, salts urea) form urine

- Urine leaves the nephrons through the ureter down to the bladder where it is stored and released via the urethra