excretory system Flashcards
what is excretion
removal of the waste product of metabolism, and substances in excess of requirements from the body.
why must carbon dioxide be excreted
Carbon dioxide must be excreted as it dissolves in water easily to form an acidic solution which can lower the pH of cells. which reduces activity of enzymes
what is the process of breaking down excess amino acids called
deanimation
how does the liver split up the amino acid
carbon is turned into glycogen
nitrogen is turned into ammonia (highly toxic) so converted to urea which is less toxic
where does the urea go
The urea dissolves in the blood and is taken to the kidney to be excreted
A small amount is also excreted in sweat
what do the lungs excrete
carbon dioxide
what is the main blood vessel that brings blood into the kidneys
renal artery
what is the main blood vessel that brings blood out of the kidney
renal vein
what carries urine from the kidney to the bladder
ureter
what are the waste substances that need to be removed from the blood
creatinine
urea
excess hormones
excess water
ammonia
uric acid
salts
in the kidney which structures help transport glucose
artery, vein
summarise the livers main 4 roles
assimilation of amino acids to form proteins
break down of the nitrogen containing parts of excess amino acids
forms urea which is excreted by the kidneys
breakdown of red blood cells
what is urine
mineral salts and urea dissolved in water
what is the urine pathway
Liver (urea) –> kidney –> ureter (urine) –> bladder –> urethera
temperature and exercise affect on volume and concentration of urine
temperature and exercise increase leads to increased dehydration and hence less volume and more concentrated urine as water content will be less.
high hydration means…
more volume and less concentrated urine
how does temperature and exercise increase dehydration
as temperature and exercise increase, more sweat is released causing the body to lose water and salts through sweat
what are the kidney’s function in the body
regulate the water content in the blood (vital for maintaining blood pressure)
excrete toxic waste products of metabolism
what is a nehpron
nephron acts as a filterate in the kidney and is the functional unit of the kidney
where is glucose reabsorbed in the nephron
proximal convuluted tube
where is urea reabsorbed in the nephron
not absorbed, excreted through urine
where are salts reabsorbed in the nephron
loop of henle