Excretion Flashcards
What is excretion?
Excretion is the removal of waste products of your body’s metabolism
What role do the kings play in excretion?
The kings excrete carbon dioxide as a gas when we exhale
Carbon dioxide is a waste product of respiration
I’d allowed to build up in the blood it can lower the ph of the blood and damage cells
What role do the kidneys play in excretion?
The kidneys filter out urea
Urea is produced by the liver
I’d allowed to build up in the body it can enter cells and lower their water potential causing them to burst
They kidneys filter out urea from the blood and excrete it as urine
What role does the liver play in excretion?
The liver helps break down many harmful substances in the blood including metabolic waste products, drugs, alcohol and toxins in our food
Draw and label liver structure
See pictures for diagram
State the functions of:- Hepatic artery- Hepatic vein Hepatic portal vein Bile duct
HA- supplies oxygenated blood to the liver
HV- takes deoxygenated blood away from the liver
HPV- brings blood from the small intestine to the liver. Any harmful substances digested are broken down straight away
Bile duct- take bile ( a substance produced by the liver to emulsify fats) to the gall bladder for storage
What shape are liver lobules?
What cells are they full of?
Liver lobules are cylindrical shaped
Full of hepatocytes
Describe the structure of a liver lobules
In the middle is a branch of the hepatic vein Around the outside are branches of the Bile duct Hepatic portal vein Hepatic artery
Which direction does the blood flow in a live lobule?
Blood flows from the hepatic artery and hepatic portal vein to the hepatic vein in the middle. On the way, the hepatocyte cells break down any harmful substances
What is the function of Kupffur cells?
Found in wall of sinusoids. They remove bacteria and break down old red blood cells
Explain scientific drawing should include?
Be done in pencil
Have clear lines
Have horizontal labels drawn with ruler
Be a simple tissue plan
Draw a liver lobule
Hepatocytes either side of a vein and artery connecting to a central vein
Explain how proteins are broken down in the liver
Protein in food is taken into the alimentary canal.
The protein molecules are broken down to amino acids during digestion
The amino acids are absorbed into the blood and taken to the liver in the hepatic portal vein
Amino acids that are needed are released into circulation
Amino acids that are not needed are reanimated, into carbohydrates and ammonia
The carbohydrates are used or stored in the liver
The ammonia is converted into urea
The urea is excreted and the amino acids to be used by the body are taken away by the blood
Draw the Ornithine cycle
NH3 + CO2 + ATP—— carbamyl PO4 ——- citrulline——- arginiosuccinate——— arginine——— ornithine
Urea comes off in between arginine and ornithine
Aspartate comes inbetween circulline
