5.2 Excretion Flashcards
what products must be excreted
carbon dioxide
nitrogen-containing compounds e.g urea
other compounds, e.g bile pigment in faeces
what are the 4 excretory organs?
lungs
liver
kidneys
skin
page 25 sutff
what is the formula for deamination
amino acid + oxygen = keto acid + ammonia
what is the formula for urea
ammonia + carbon dioxide = urea + water
what is the function of bile
used for digestion and excretion
what is the route bile takes
liver > gall bladder where it is stored. bile pigments such as bilirubin will leave in faeces
what are the holes in liver lobules
inter-lobular vessels
what are the collumns of liver cells called
sinusoid
what are kupffers and what do they do
specialised macrophages that breakdown and recycle old red blood cells, breakdown produces bilirubin
what are the cells in the liver called
hepatocytes
what are the metabolic functions of the liver
controls glucose levels
synthesis of bile, plasma proteins, cholersterol
synthesis of rbc
storage vitamins
detoxificaiton
breakdown of hormones
destruction of rbc
enzymes used in detoxification
catalase - converts hydrogen peroxide to oxygen and water (high turnover number)
cytochrome P450 - cocaine and medicinal drugs
how is alcohol broken down
enzyme ethanol dehydrogenase , final compound is ethanoate.
page 29 ornitihine cycle or smthg
label a kidney
what are the tubules in the kidney called
nephrons
what are the two labels for the arterioles in the bowmans capsule glomerular capillary
efferent and afferent
what are the cells on the isnide of the bowmans capsule
podocytes
what is the basement membrane made of
mesh of collagen fibres
what are the 3 parts to the nephron
proximal convoluted tubules
loop of henle
distal convoluted tubule
how does blood flow through the glomerulus
the afferent arteriole is smaller and has a higher pressure than efferent
what is filtered out of the blood
water
amino acids
glucose
urea
inorganic mineral ions (NA, CL, K)
What hapopens in the PCT
85% fluid reabsorbed which decreases water potential
what happens in the descending limb
additional mineral ions and reduction of water
what happens in the ascending limb
mineral ions activley transported out and water in
what happens in collecting duct
removal of water leaves urine
what happens at the cells idk
sodium in by active transport and cotransports glucose or amino acids which reduce water potential so water enters cells
page 34 diagram
what happens to the walls of the collecting duct on a cool day
become less permeable so less water is reabsorbed
what happens to the walls of the collecting duct on a warm day
becomes more permeable so that more water is reabsorbed
What is the hormone produced to signal permeability of the collecting duct
antidiuretic hormone (ADH)
how does ADH afffect wall permeability
more adh signals for the vesicles containing aquaporins to fuse with cell surface membrane and becomes more permeable
less is the opposite and removes aquaporins
how does the body signal for more or less ADH
osmoreceptors in the hypothalamus shrivel when the water potential is low in the blood so signal for neurosecretory cells
page 37 diagram
