Kidneys Flashcards
Sphincter muscle function
Keeps bladder closed
Vena cava function
Main vein returning blood to the heart
Ureters function
Carry urine to the bladder
Bladder
Muscular sac that stores urine
Urethra function
Carries urine out of the body
What takes ‘cleaned’ blood away from the kidneys
Renal vein
Renal artery function
Brings blood containing ‘waste’ to the kidneys
Main artery supplying oxygenated blood to the body
Aorta
Lighter middle layer of kidney
Medulla
Darker outer layer of kidney
Cortex
Nephron function
Filtration unit (where urine is produced)
Central cavity which collects urine
Pelvis
Main function of kidneys
To get rid of waste such as urea, extra salts/mineral ions and extra water
Effect of eating salt on urine composition (3 steps, simple)
Blood solute concentration increases
Urine volume decreases
Water kept in blood
What happens in ultrafiltration?
Small molecules are filtered out of the blood
Large molecules stay in the blood
What features make ultrafiltration work?
- high pressure of blood
- gaps in the walls of the glomerulus & bowman’s capsule
What happens in selective
Reabsorption? 3
Useful molecules are reabsorbed back into the bloodstream by active transport
Some water moves back into the blood by osmosis
Urea stays in the filtrate
Summary what happens when low water (high solute) concentration in blood 4
1) ADH secreted
2) collecting ducts become more permeable to water
3) more water is reabsorbed into bloodstream
4) less urine is produced
Summary what happens when high water (low solute) concentration in blood 4
1) no ADH secreted
2) collecting ducts become less permeable to water
3) less water is reabsorbed into bloodstream
4) more urine is produced
How comes the blood entering the kidney is at high pressure?
The renal artery which supplies the blood to the kidneys leads straight from the body’s main artery, the aorta
Main nitrogenous excretory substance in humans
Urea
When is waste urea produced?
When amino acids are broken down in your liver
What happens to amino acids in the digestive system
They are taken up into the bloodstream (in the ileum) & then transported to cells that need them to build new proteins
Toxic waste product of metabolic reaction
Ammonia
