Embed Size (px)
Citation preview
2006-2007 AP Biology
Regulating the InternalEnvironment
2006-2007 AP Biology
Credit: created by
Kim Fogler
Division Avenue High SchoolLevittown
AP Biology
Conformers vs. Regulators 2 methods for organisms
regulate internal environment maintain relatively constant internal conditions
conform to external environment allow internal conditions to fluctuate along with external changes
conformer
thermoregulation
regulator
conformer
osmoregulation
regulator
AP Biology
Homeostasis Keeping the balance
animal body needs to coordinate many systems all at once temperature blood sugar levels energy production water balance & intracellular waste disposal nutrients ion balance cell growth
maintaining a “steady state” condition
2006-2007 AP Biology
Regulating the InternalEnvironmentWater Balance &
Nitrogenous Waste Removal
AP Biology
intracellular waste
extracellular waste
Animal systems designed to support multicellular life
O2
CHO
CHO
aa
aa
CH
CO2
NH3aa
O2
CH
O2
aa
CO2
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
CO2
NH3
NH3 NH3
NH3
NH3
NH3
NH3NH3
O2
aa
CH
aa
CHO
O2
Diffusion too slow!
AP Biology
Solving exchange problem Multicellular systems for
distributing nutrients circulatory system
removing wastes excretory system
overcoming the limitations of diffusion
overcoming the limitations of diffusion
aa
CO2
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
CO2
NH3
NH3 NH3
NH3
NH3
NH3
NH3NH3
O2
aa
CH
aa
CHO
O2
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 freshwater
hypotonic water flow into cells & salt loss
saltwater hypertonic water loss from cells
land dry environment need to conserve water may need to conserve salt
AP Biology
Waste disposal What waste products?
what do we digest our food into… carbohydrates = CHO lipids = CHO proteins = CHON nucleic acids = CHOPN
relatively small amount in cell
CO2 + H2O
NH2 =
ammonia
CO2 + H2O CO2 + H2O
CO2 + H2O + N
CO2 + H2O + P + N
|
| ||H
HN C–OH
O
R
H–C–
Animalspoison themselves
from the insideby digesting
proteins!
cellular digestion…cellular waste
AP Biology
Nitrogenous waste disposal Ammonia (NH3)
very toxic carcinogenic
very soluble easily crosses membranes
must dilute it & get rid of it… fast!
How you get rid of nitrogenous wastes depends on who you are where you live (habitat)
AP Biology
AP Biology
Aquatic organismscan afford to
lose water ammonia
most toxic
Terrestrialneed to
conserve waterurea
less toxic
Terrestrial egglayersneed to conserve
most wateruric acid
least toxic
Nitrogen waste
AP Biology
Freshwater animals Water removal & nitrogen waste disposal
surplus of water can dilute ammonia & excrete it
need to excrete a lot of water anyway so excrete very dilute urine
pass ammonia continuously through gills or through any moist membrane
loss of salts reabsorb in kidneys or active transport across gills
AP Biology
Land animals Nitrogen waste disposal on land
have less toxic waste product need to conserve water urea = less soluble = less toxic
kidney filter wastes out of blood reabsorb H2O
excrete waste urine = urea, salts, excess sugar & H2O
urine is very concentrated concentrated NH3 would be too toxic
AP Biology
Urea Larger molecule = less soluble
2NH2 + CO2 = urea combined in liver
Requires energy to produce worth the investment
of energy
Filtered out by kidneys collected from cells
by circulatory system
H
HN
H
HN
C O
AP Biology
Egg-laying land animals Nitrogen waste disposal in egg
no place to get rid of waste in egg need even less soluble molecule
uric acid = bigger = less soluble = less toxic birds, reptiles, insects
itty bittyliving space!
AP Biology
N
N N
N
O
HO
O
H
HH
Uric acid Polymerized urea
large molecule precipitates out of solution
doesn’t harm embryo in eggwhite dust in egg
adults excrete white pasteno liquid wastewhite bird “poop”!
And that folks,is why a male bird
doesn’t have a penis!
AP Biology
Mammalian System Key functions
filtration fluids from blood collected includes water & solutes
reabsorption selectively reabsorb needed
substances back to blood secretion
pump out unwanted substances to urine
excretion remove excess substances & toxins
from body
blood filtrate
urine
AP Biology
Organs of the Urinary systemOrgans of the Urinary system
Kidneys
Ureters
Urinary bladder
Urethra
AP Biology
Location of the KidneysLocation of the Kidneys
Against dorsal wall
Right lower than left
Attached to ureters, renal blood vessels, & nerves at renal hilus
Atop kidney is adrenal gland
AP Biology
Regions of the KidneyRegions of the Kidney
Renal cortex – outer region
Renal medulla – inside the cortex
Renal pelvis – inner collecting tube
AP Biology
Mammalian Kidney
kidney
bladder
ureter
urethra
inferiorvena cava
renal vein& artery
nephron
epithelialcells
aortaadrenal gland
AP Biology
Nephron Functional and structural units
of kidney1 million nephrons
per kidney Function
filter out urea & solutes (salt, sugar…) : form urine
Processblood plasma filtered
into nephronselective reabsorption of
valuable solutes & H2O greater flexibility & control
“counter current exchange system”
AP Biology
The Kidney
Proximaltubule
Distal tubule
Glomerulus
Collecting ductLoop of Henle
Aminoacids
Glucose
H2O
H2O
H2O
H2O
H2O
H2O
Na+ Cl-
Mg++ Ca++
Interaction of circulatory & excretory systems
Circulatory system glomerulus =
ball of capillaries Excretory system
nephron Bowman’s capsule loop of Henle
descending limb ascending limb
collecting duct
How candifferent sectionsallow the diffusion
of different molecules?
Bowman’s capsule
Na+ Cl-
AP Biology
Nephron: Filtration At glomerulus
filtered out of blood H2O
glucose salts / ions urea
not filtered out cells proteins
high blood pressure in kidneys force to push H2O & solutes out of blood vessel
high blood pressure in kidneys force to push H2O & solutes out of blood vessel
BIG problems when you start out with high blood pressure in systemhypertension = kidney damage
BIG problems when you start out with high blood pressure in systemhypertension = kidney damage
AP Biology
Nephron: Re-absorption
Descendinglimb
Ascendinglimb
Proximal tubule reabsorbed
NaCl active transport Na+
Cl- follows by diffusion
H2O glucose HCO3
-
bicarbonate buffer for
blood pH
AP Biology
Descendinglimb
Ascendinglimb
Nephron: Re-absorption Loop of Henle
descending limb high permeability to
H2O
many aquaporins in cell membranes
low permeability to salt
reabsorbed H2O
structure fitsfunction!
AP Biology
Nephron: Re-absorption
Descendinglimb
Ascendinglimb
Loop of Henleascending limb
low permeability to H2O
Cl- pump Na+ follows by
diffusion different membrane
proteins
reabsorbed salts
maintains osmotic gradient
structure fitsfunction!
AP Biology
Nephron: Re-absorption Distal tubule
reabsorbed salts H2O
HCO3-
bicarbonate
AP Biology
Nephron: Reabsorption & Excretion Collecting duct
reabsorbed H2O
excretion urea passes to
bladderDescending
limbAscending
limb
AP Biology
Osmotic Control of nephron How is all this re-absorption achieved?
tight osmotic control to reduce the energy cost of excretion
use diffusion instead of active transportwherever possible
the value of acounter current exchange system
AP Biology
AP Biology
Summary Not filtered out
remain in blood (too big) cells proteins
Reabsorbed: active transport Na+ amino acids Cl- glucose
Reabsorbed: diffusion Na+ Cl-
H2O Excreted
urea (highly concentrated) excess H2O excess solutes (glucose, salts) toxins, drugs, “unknowns”
2006-2007 AP Biology
Any Questions?
2006-2007 AP Biology
Regulating the InternalEnvironment
Regulation of Homeostasis
AP Biology
Sensorconstantlymonitors
conditions
Negativefeedback loop
completed
ResponseReturn toset point
Stimulusdeviation from
set point
Perturbingfactor
Effectorcauses changesto compensatefor deviation
Integratingcentercomparesconditions toset point
Negative Feedback Loop Maintaining homeostasis
AP Biology
sensor
Negative Feedback Model
high
low
hormone 1
lowersbody condition(return to set point)
hormone 2
gland
raisesbody condition (return to set point)
gland
sensor
specific body condition
AP Biology
Controlling Body Temperature
high
low
nerve signals
sweat
nerve signals
brain
body temperature
shiver brain
dilates surfaceblood vessels
constricts surfaceblood vessels
Nervous System Control
AP Biology
nephron
low
Blood Osmolarity
blood osmolarityblood pressure
ADH
increasedwater
reabsorption
increasethirst
high
Endocrine System Control
pituitary
AP Biology
H2O
H2O
H2O
Maintaining Water BalanceGet morewater intoblood fast
Alcohol suppresses ADH…
makes youurinate a lot!
High blood osmolarity level too many solutes in blood
dehydration, high salt diet stimulates thirst = drink more release ADH from pituitary gland
anti-diuretic hormone increases permeability of collecting duct
& reabsorption of water in kidneys increase water absorption back into blood decrease urination
AP Biology
nephron
low
Blood Osmolarity
blood osmolarityblood pressure
ADH
increasedwater
reabsorption
increasethirst
renin
increasedwater & saltreabsorption
high
Endocrine System Control
pituitary
angiotensinogenangiotensin
nephronadrenalgland
aldosterone
JuxtaGlomerularApparatus
AP Biology
Maintaining Water Balance
Low solutes
renin (from JGA) activatesangiotensinogen
angiotensin triggers aldosterone
aldosteroneincreases absorption
of NaCl & H2O in kidney
Oooooh,zymogen!
Low blood osmolarity level or low blood pressure
AP Biology
Maintaining Water Balance Low blood osmolarity level
or low blood pressure JGA releases renin in kidney renin converts angiotensinogen to angiotensin angiotensin causes arterioles to constrict
increase blood pressure angiotensin triggers release of aldosterone from
adrenal gland increases reabsorption of NaCl & H2O in kidneys
puts more water & salts back in blood
Get morewater & salt into
blood fast!
adrenalgland
AP Biology
Homeostasis Osmoregulation
solute balance & gain or loss of water Excretion
elimination of nitrogenous wastes
Thermoregulation maintain temperature within tolerable range
AP Biology
Maintaining Water Balance Monitor blood osmolarity
amount of dissolved material in blood
in brain
ADH = anti-diuretic hormone
High solutes
