AP Biology Kidney Structure & Function Collecting duct Loop
of Henle Amino acids Glucose H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O
H2OH2O Na + Cl - Mg ++ Ca ++ Na + Cl - Removing Intracellular
Waste
Slide 3
AP Biology intracellular waste Animal systems evolved to
support multicellular life O2O2 CHO aa CH CO 2 NH 3 aa O2O2 CH O2O2
aa CO 2 NH 3 O2O2 aa CH aa CHO O2O2 Diffusion too slow! single cell
but what if the cells are clustered? for nutrients in & waste
out extracellular waste
Slide 4
AP Biology Overcoming limitations of diffusion Evolution of
exchange systems for distributing nutrients _____________________
removing wastes _____________________ systems to support
multicellular organisms aa CO 2 NH 3 O2O2 aa CH aa CHO O2O2
Slide 5
AP Biology Osmoregulation Why do all land animals have to
conserve water? always lose water (breathing & waste) may lose
life while searching for water Water balance vs. Habitat freshwater
___________________________ water flow into cells & salt loss
saltwater ___________________________ water loss from cells land
dry environment need to conserve water may also need to conserve
salt hypotonic hypertonic
Slide 6
AP Biology Intracellular Waste What waste products are made
inside of cells? what do we digest our food into carbohydrates =
CHO lipids = CHO proteins = CHON nucleic acids = CHOPN CO 2 + H 2 O
NH 2 = ammonia CO 2 + H 2 O CO 2 + H 2 O + N CO 2 + H 2 O + P + N |
||| H H N COH O R H C Animals poison themselves from the inside by
digesting proteins! lots! very little cellular digestion cellular
waste
Slide 7
AP Biology Nitrogenous waste disposal Ammonia (NH 3 )
__________________________ carcinogenic __________________________
easily crosses membranes must dilute it & get rid of it fast!
How you get rid of ___________________depends on who you are
(evolutionary relationship) where you live (habitat)
aquaticterrestrialterrestrial egg layer
Slide 8
AP Biology Nitrogen waste _____________________ can afford to
lose water ___________________ most toxic _____________________
need to conserve water ___________________ less toxic
______________________ ______________________ need to conserve
water need to protect embryo in egg ___________________ least
toxic
Slide 9
AP Biology Freshwater animals Hypotonic environment water
diffuses into cells Manage water & waste together remove
surplus water & waste use surplus water to dilute ammonia &
excrete it also diffuse ammonia continuously through gills overcome
loss of salts reabsorb in kidneys or active transport across
gills
Slide 10
AP Biology Land animals Nitrogen waste disposal on land need to
conserve water must process ammonia so less toxic _______= larger
molecule = less soluble = less toxic 2NH 2 + CO 2 = urea
_________________________ __________________ filter solutes out of
blood reabsorb H 2 O (+ any useful solutes) excrete waste _______ =
urea, salts, excess sugar & H 2 O urine is very concentrated
concentrated NH 3 would be too toxic O C H N H H N H Urea costs
energy to synthesize, but its worth it! mammals
Slide 11
AP Biology Nitrogen waste disposal in egg no place to get rid
of waste in egg need even less soluble molecule ___________ =
BIGGER = less soluble = less toxic birds, reptiles, insects
Egg-laying land animals itty bitty living space!
Slide 12
AP Biology N N N N O H O O H H H Uric acid And that folks, is
why most male birds dont have a penis! Polymerized urea large
molecule ______________________________ doesnt harm embryo in egg
white dust in egg adults still excrete N waste as white paste no
liquid waste uric acid = white bird poop!
Slide 13
AP Biology Mammalian System Filter solutes out of blood &
reabsorb H 2 O + desirable solutes Key functions
______________________ fluids (water & solutes) filtered out of
blood ______________________ selectively reabsorb (diffusion)
needed water + solutes back to blood ______________________ pump
out any other unwanted solutes to urine ______________________
expel concentrated urine (N waste + solutes + toxins) from body
bloodfiltrate concentrated urine filtrate
Slide 14
AP Biology Mammalian Kidney kidney bladder ureter urethra renal
vein & artery nephro n microvilli on epithelial cells adrenal
gland inferior vena cava aorta
Slide 15
AP Biology Nephron Functional units of kidney 1 million
nephrons per kidney Function filter out urea & other solutes
(salt, sugar) blood plasma filtered into nephron high pressure flow
selective reabsorption of valuable solutes & H 2 O back into
bloodstream greater flexibility & control counter current
exchange system why selective reabsorption & not selective
filtration?
Slide 16
AP Biology Mammalian kidney Proximal tubule Distal tubule
Glomerulus Collecting duct Loop of Henle Amino acids Glucose H2OH2O
H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O Na + Cl - Mg ++ Ca ++
Interaction of circulatory & excretory systems How can
different sections allow the diffusion of different molecules?
Bowmans capsule Na + Cl -
Slide 17
AP Biology Nephron: _______________ At glomerulus high blood
pressure in kidneys force to push (filter) H 2 O & solutes out
of blood vessel BIG problems when you start out with high blood
pressure in system hypertension = kidney damage H 2 O & solutes
cells & large molecules
Slide 18
AP Biology Nephron: _______________ Proximal tubule reabsorbed
back into blood
Slide 19
AP Biology Nephron: Re-absorption structure fits function! Loop
of Henle ___________________ reabsorbed _________________
structure
Slide 20
AP Biology Nephron: Re-absorption structure fits function! Loop
of Henle ___________________ reabsorbed _________________
structure
Slide 21
AP Biology Nephron: Re-absorption Distal tubule reabsorbed
AP Biology Osmotic control in nephron How is all this
re-absorption achieved? tight osmotic control to reduce the energy
cost of excretion use diffusion instead of active transport
wherever possible the value of a counter current exchange
system
Slide 24
AP Biology Summary why selective reabsorption & not
selective filtration?