5.1.2

Created by

Emme

Cards (91)

key excretory organs
kidneys
liver
lungs
excretion
the removal of unwanted products of metabolism
unwanted products of metabolism
urea , carbon dioxide , bile pigments
how is carbon dioxide excreted 
from the lungs via the bloodstream
why must carbon dioxide be removed 
too much carbon dioxide in the blood decreases the blood pH and supplies cells with less oxygen causing reduced metabolic rate and death
what blood supplies does the liver have?
hepatic artery
hepatic portal vein
the liver splits into
2 lobes that split into lobules
lobule 
a hexagonal shaped structure containing hepatocytes
function of the liver 
glycogen storage
detoxification
urea formation
hepatocytes 
epithelial liver cells that contain lots of mitochondria and a large nuclei so they can regenerate often
how do hepatocytes respond to insulin 
they absorb glucose from the blood converting it to glycogen. The opposite occurs in response to glucagon
portal vein 
brings blood that needs treating from the digestive system. It is big and branched
hepatic artery 
supplies the liver with oxygenated blood from the lungs and heart. It is narrow and small
sinusoid 
A channel where the blood from the portal vein and artery mix supplying oxygen to hepatocytes. It is filled with Kupffer cells that destroy dead blood cells and pathogens
what would happens if Kupffer cells were not present in the liver 
the skin would turn yellow due to all the dead blood cells still circulating
central vein 
a drain removing all the filtered blood
bile canaliculi 
where hepatocytes drain the bile into
bile duct 
where hepatocytes secrete the bile from the breakdown of haemoglobin from old red blood cells and it is taken to the gall bladder. It has no wall instead is surrounded by hepatic cells.
urea 
produced from the excess amino acids in the liver
why can amino acids not ben stored 
they are acidic so damage cells
process of dealing with excess amino acids involves
deamination and the ornithine cycle
deamination 
the removal of the amine group from the amino acid to form ammonia and a keto acid
why can ammonia not be stored in the body? 
it is soluble and highly toxic
what is a keto acid used for 
in the Krebs cycle for respiration
converted into glucose or fat
what is ammonia turned into 
urea
the ornithine cycle 
A cyclic event that requires ATP and occurs within the mitochondria of hepatocytes. It turns ammonia into urea using water and carbon dioxide
detoxification in hepatocytes 
poisonous substances produced from metabolic pathways are made harmless such as hydrogen peroxide being turned into water and oxygen within hepatocytes
conversion of ethanol in hepatocytes 
alcohol dehydrogenase turns ethanol into ethanal which is turned into other molecules used in the Krebs's cycle , this generates ATP leading to fat storage and fatty liver. This can lead to cirrhosis where the liver lacks blood and contains and increased concentration of ammonia
function of the kidney 
responsible for the extraction of nitrogenous waste and osmoregulation
osmoregulation 
the process of controlling blood water potential
renal artery 
Supplies blood that needs to be filtered
renal vein 
carries away filtered blood
cortex 
contains many capillary networks that carry blood from the renal artery to the nephrons
medulla 
contains nephrons and lots of blood giving it a darker colour
pelvis 
where the urine collects before going to the ureter
nephron 
structures where the blood is filtered
Mammalian liver diagram
A) Hepatic vein
B) hepatic artery
C) Hepatic portal vein
D) bile duct
E) gall bladder
Lobule diagram
A) bile duct
B) Hepatic vein
C) sinusoid
D) Hepatic portal vein
E) hepatic artery
lobule diagram detailed
A) hepatocytes
B) Kupffer cell
C) bile canaliculi
lobule histology
A) central vein
B) portal vein
C) bile duct
D) hepatic artery