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Transcript of Coordination and Control Within a Body Endocrine system: transmits chemical signals (hormones) to...
Coordination and Control Within a Body
• Endocrine system: transmits chemical signals (hormones) to receptive cells throughout body via blood– Slow acting, long-lasting effects
• Nervous system: neurons transmit info between specific locations– Very fast!– Info received by: neurons, muscle cells,
endocrine cells
© 2011 Pearson Education, Inc.
Homeostasis• Maintain a “steady state” or internal balance
regardless of external environment• Fluctuations above/below a set point serve as a
stimulus; these are detected by a sensor and trigger a response
• The response returns the variable to the set point
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Negative Feedback
• “More gets you less.”• Return changing
conditions back to set point
• Examples:– Temperature– Blood glucose levels– Blood pH
Plants: response to water limitations
Positive Feedback
• “More gets you more.”• Response moves variable
further away from set point
• Stimulus amplifies a response
• Examples:– Lactation in mammals– Onset of labor in childbirth
Plants: ripening of fruit
Do Now:
• Animals get energy from FOOD• Digestion provides monomers required
for…• ATP synthesis, cellular work, and
biosynthesis (growth, repair, reproduction)
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12
What is thermoregulation?
• Maintaining of internal temperatures in an organism
• Two major classes of organisms: endotherms and ectotherms
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Are these endotherms or ectotherms?
• ENDOTHERMS
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Characteristics of Endotherms:
• Maintain constant internal body temp regardless of external temp
• Generate heat from metabolism (C.R.)• Requires more energy• Higher Metabolic Rates
– Highest in very COLD temps (why?)
• Birds and Mammals
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Characteristics of Ectotherms
• Internal temp changes with the environmental temp
• Get heat from external sources• Lower metabolic rates• Less food intake• Behavioral adaptations
Play an impt role• Reptiles, amphib, fish
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Figure 40.10
How does this graph characterize the relationship between environmental temperature and body temperature of endotherms and ectotherms?
An organisms metabolic rate is the sum of all energy requiring chemical reactions. How can scientists measure the metabolic rate of organisms?• Oxygen consumption• CO2 production• Heat Loss
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Comparing the energy expenditures in various sized endotherms and ectotherms• Observations:
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How does the size of an organism affect is metabolic rate? (Comparison of various mammals) • Observations and Predictions
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Five adaptations for thermoregulation:• Insulation (skin, feather, fur, blubber)• Circulatory adaptations (countercurrent exchange)• Cooling by evaporative heat loss (sweat)• Behavioral responses (shivering, shade, basking)• Adjusting metabolic heat production (“antifreeze”)
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25.3 Thermoregulation involves adaptations that balance heat gain and loss
• Five general categories of adaptations help animals thermoregulate.
© 2012 Pearson Education, Inc.
Figure 25.3_UN01
• 1) Increased metabolic heat production occurs when– hormonal changes boost the metabolic rate in
birds and mammals,– birds and mammals shiver,– organisms increase their physical activity, and– honeybees cluster and shiver.
25.3 Thermoregulation involves adaptations that balance heat gain and loss
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• Insulation is provided by– hair,– feathers, and– fat layers.
25.3 Thermoregulation involves adaptations that balance heat gain and loss
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• Circulatory adaptations include– increased or decreased blood flow to skin and– countercurrent heat exchange, with warm and
cold blood flowing in opposite directions.
25.3 Thermoregulation involves adaptations that balance heat gain and loss
© 2012 Pearson Education, Inc.
• Evaporative cooling may involve– sweating, – panting, or– spreading saliva on body surfaces.
25.3 Thermoregulation involves adaptations that balance heat gain and loss
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Figure 25.3_1
Heat dissipation(Via ear flapping)
EvaporativeCooling
• Behavioral responses– are used by endotherms and ectotherms and– include
» moving to the sun or shade,» migrating, and» bathing.
25.3 Thermoregulation involves adaptations that balance heat gain and loss
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Color changes
What are these organisms doing???
Torpor and Energy Conservation
• Torpor is a physiological state in which activity is low and metabolism decreases
• Save energy while avoiding difficult and dangerous conditions
• Hibernation: torpor during winter cold and food scarcity
• Estivation: summer torpor, survive long periods of high temperatures and scarce water
© 2011 Pearson Education, Inc.
Figure 25.3_UN01
• Circulatory adaptations include– increased or decreased blood flow to skin and
– countercurrent heat exchange, with warm and cold blood flowing in opposite directions.
25.3 Thermoregulation involves adaptations that balance heat gain and loss
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Figure 25.3_1Ear flapping to release excess heat; water spray for evaporative cooling
Figure 25.3_2
Blood frombody corein artery
Bloodreturning tobody corein vein
Blood frombody corein artery
Bloodreturningto bodycore in vein
35
30
20
10
33C
27
18
9
Figure 40.12
What is countercurrent heat exchange?
Animation
What is countercurrent heat exchange?
• Prevents the loss
Of a large amount of
Heat by transferring
Heat from warm
Blood to cooler
Adjacent blood
36
Animation
Which body systems are involved in mammalian thermoregulation?• Integumentary (skin)• Muscular• Circulatory
37
Figure 40.16
When body temperature decreases:Shivering and Constriction of Blood Vessels
When body temperature increases: Sweating and dilation of blood vessels
• Metabolic rate: amount of energy an animal uses in a unit of time
• Standard metabolic rate (SMR): ectotherm at rest at a specific temperature
• Basal metabolic rate (BMR): endotherm at rest at a “comfortable” temperature
What is an organisms metabolic rate?
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Figure 40.19
Observations:
OSMOREGULATION
AND EXCRETION
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Osmoregulation is the homeostatic control of the uptake and loss of water and solutes such as salt and other ions.
Osmosis is one process whereby animals regulate their uptake and loss of fluids.
25.4 Animals balance the level of water and solutes through osmoregulation
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25.4 Animals balance the level of water and solutes through osmoregulation
• Osmoconformers– have body fluids with a solute concentration
equal to that of seawater,– face no substantial challenges in water balance,
and– include many marine invertebrates.
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25.4 Animals balance the level of water and solutes through osmoregulation
Osmoregulators• have body fluids whose solute concentrations differ from
that of their environment,• must actively regulate water movement, and• include
– many land animals,– freshwater animals such as trout, and– marine vertebrates such as sharks.
© 2012 Pearson Education, Inc.
25.4 Animals balance the level of water and solutes through osmoregulation
Freshwater fish• gain water by osmosis (mainly through gills),• lose salt by diffusion to the more dilute environment,• take in salt through their gills and in food, and • excrete excess water in dilute urine.
© 2012 Pearson Education, Inc.
Figure 25.4_1
Fresh water
Excretion of largeamounts of waterin dilute urinefrom kidneys
Uptakeof salt ionsby gills
Uptake ofsome ionsin food
Osmotic water gain through gillsand other parts of body surface
• Saltwater fish– lose water by osmosis from the gills and body
surface,– drink seawater, and– use their gills and kidneys to excrete excess
salt.
25.4 Animals balance the level of water and solutes through osmoregulation
© 2012 Pearson Education, Inc.
Figure 25.4_2
Gain of water andsalt ions from foodand by intake ofseawater
Osmotic water loss through gills and other parts of body surface
Salt water
Excretion of excess ionsand small amounts ofwater in concentratedurine from kidneys
Excretion of salt from gills
• Land animals– face the risk of dehydration,– lose water by evaporation and waste disposal, – gain water by drinking and eating, and– conserve water by
• reproductive adaptations, • behavior adaptations,• waterproof skin, and• efficient kidneys.
25.4 Animals balance the level of water and solutes through osmoregulation
© 2012 Pearson Education, Inc.
25.5 EVOLUTION CONNECTION: A variety of ways to dispose of nitrogenous wastes has evolved in animals
• Metabolism produces toxic by-products.• Nitrogenous wastes are toxic breakdown
products of proteins and nucleic acids.• Animals dispose of nitrogenous wastes in
different ways.
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• Ammonia (NH3) is– poisonous,– too toxic to be stored in the body,– soluble in water, and– easily disposed of by aquatic animals.
25.5 EVOLUTION CONNECTION: A variety of ways to dispose of nitrogenous wastes has evolved in animals
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• Urea is– produced in the vertebrate liver by combining
ammonia and carbon dioxide,– less toxic,– easier to store, and– highly soluble in water.
25.5 EVOLUTION CONNECTION: A variety of ways to dispose of nitrogenous wastes has evolved in animals
© 2012 Pearson Education, Inc.
• Uric acid is– excreted by some land animals (insects, land
snails, and many reptiles),– relatively nontoxic,– largely insoluble in water,– excreted as a semisolid paste, conserving
water, but– more energy expensive to produce.
25.5 EVOLUTION CONNECTION: A variety of ways to dispose of nitrogenous wastes has evolved in animals
© 2012 Pearson Education, Inc.
Figure 25.5
Proteins
Ammonia
Nitrogenous bases
NH2
(amino groups)
Nucleic acids
Urea
Uric acid
Mammals, mostamphibians, sharks,some bony fishes
Birds and many otherreptiles, insects, landsnails
Most aquatic animals,including most bonyfishes
Amino acids
25.6 The urinary system plays several major roles in homeostasis
• The urinary system– forms and excretes urine and– regulates water and solutes in body fluids.
• In humans, the kidneys are the main processing centers of the urinary system.
© 2012 Pearson Education, Inc.
• Nephrons
– are the functional units of the kidneys,
– extract a fluid filtrate from the blood, and
– refine the filtrate to produce urine.
• Urine is
– drained from the kidneys by ureters,
– stored in the urinary bladder, and
– expelled through the urethra.
25.6 The urinary system plays several major roles in homeostasis
© 2012 Pearson Education, Inc.
Animation: Nephron Introduction
Figure 25.6
Aorta
Kidney
The urinary system
Inferiorvena cava
Renal artery (red)and vein (blue)
Ureter
Urethra
Urinary bladder
Renal cortex
Renal medulla
Renal pelvis
Ureter
The kidney
Proximal tubule
Bowman’s capsule
Tubule
Collectingduct
To renalpelvis
Branch ofrenal artery
Branch ofrenal vein
Renal cortex
Renal medulla
CapillariesGlomerulus
Distaltubule
Fromanothernephron
Bowman’s capsuleArteriole
from renalartery
Arteriolefrom glomerulus
Branch ofrenal vein
Loop of Henlewith capillarynetwork
Detailed structure of a nephron
1
3
2
Orientation of a nephron within the kidney
Collectingduct
Figure 25.6_1
Aorta
Kidney
The urinary system
Inferiorvena cava
Renal artery (red)and vein (blue)
Ureter
Urethra
Urinary bladder
Figure 25.6_2
Renal cortex
Renal medulla
Ureter
Renal pelvis
The kidney
Figure 25.6_3
Bowman’s capsule
Tubule
Collectingduct
To renalpelvis
Branch ofrenal artery
Branch ofrenal vein
Renal cortex
Orientation of a nephron within the kidney
Renal medulla
Figure 25.6_4
Proximal tubuleGlomerulus
DistaltubuleCollectingDuct
Fromanothernephron
Bowman’s capsule
Arteriolefrom renalartery
Arteriolefrom glomerulus
Branch ofrenal vein
Loop of Henlewith capillarynetwork
Detailed structure of a nephron
Capillaries
1
3
2
25.7 Overview: The key processes of the urinary system are filtration, reabsorption, secretion, and excretion
• Filtration– Blood pressure forces water and many small
molecules through a capillary wall into the start of the kidney tubule.
• Reabsorption– refines the filtrate,– reclaims valuable solutes (such as glucose,
salt, and amino acids) from the filtrate, and– returns these to the blood.
© 2012 Pearson Education, Inc.
Figure 25.7
Reabsorption Secretion Excretion
Urine
To renal vein
Filtration
Nephron tubule
Capillary
Interstitial fluid
H2O, other small molecules
Bowman’s capsule
Fromrenalartery
Figure 25.7_1
Filtration
Nephron tubule
Capillary
Interstitial fluid
H2O, other small molecules
Bowman’s capsule
Fromrenalartery
Figure 25.7_2
Reabsorption Secretion Excretion
Urine
To renal veinCapillary
Nephron tubule
• Substances in the blood are transported into the filtrate by the process of secretion.
• By excretion the final product, urine, is excreted via the ureters, urinary bladder, and urethra.
25.7 Overview: The key processes of the urinary system are filtration, reabsorption, secretion, and excretion
© 2012 Pearson Education, Inc.
Figure 25.7
Reabsorption Secretion Excretion
Urine
To renal vein
Filtration
Nephron tubule
Capillary
Interstitial fluid
H2O, other small molecules
Bowman’s capsule
Fromrenalartery
• Reabsorption in the proximal and distal tubules removes– nutrients,– salt, and– water.
• pH is regulated by– reabsorption of HCO3
– and
– secretion of H+.
25.8 Blood filtrate is refined to urine through reabsorption and secretion
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• High NaCl concentration in the medulla promotes reabsorption of water.
25.8 Blood filtrate is refined to urine through reabsorption and secretion
© 2012 Pearson Education, Inc.
Animation: Bowman’s Capsule and Proximal Tubule
Animation: Collecting Duct
Animation: Effect of ADH
Animation: Loop of Henle and Distal Tubule
Figure 25.8 Bowman’scapsule
Blood
Nutrients H2ONaCl
Proximal tubule
Somedrugsand poisonsCortex
Medulla
Interstitialfluid Loop of
Henle
H2O
Filtrate composition
Reabsorption
Filtrate movement
Secretion
Distal tubule1
2 NaCl
NaCl
NaCl
UreaH2O
3K
H
Collectingduct
Urine (torenal pelvis)
H2ONaCl HCO3
H2O
Salts (NaCl and others) HCO3
H
Urea Glucose Amino acids Some drugs
HCO3
H
Figure 25.8_1
Blood
Filtrate composition
Reabsorption
Filtrate movement
Secretion
Bowman’scapsule
Nutrients H2ONaCl HCO3
Proximal tubule
Somedrugsand poisonsCortex
Medulla
H
H2O
Salts (NaCl and others) HCO3
H
Urea Glucose Amino acids Some drugs
Figure 25.8_2
Reabsorption
Filtrate movement
Secretion
NutrientsNaCl HCO3
Somedrugsand poisonsCortex
Medulla
Proximal tubule
Interstitialfluid Loop of
Henle
H2O
NaCl
NaCl
NaCl
UreaH2O
Collectingduct
Urine (torenal pelvis)
Distal tubuleH2O
NaCl HCO3
1
3
2
H2O
H HK
• Antidiuretic hormone (ADH) regulates the amount of water excreted by the kidneys by– signaling nephrons to reabsorb water from the
filtrate, returning it to the blood, and– decreasing the amount of water excreted.
• Diuretics– inhibit the release of ADH and– include alcohol and caffeine.
25.9 Hormones regulate the urinary system
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• Kidney failure can result from– hypertension,– diabetes, and– prolonged use of common drugs, including
alcohol.
• A dialysis machine– removes wastes from the blood and– maintains its solute concentration.
25.10 CONNECTION: Kidney dialysis can be lifesaving
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Figure 25.9
Line from artery to apparatus
Pump Tubing made of a selectively permeable membrane
Dialyzingsolution
Fresh dialyzingsolution
Used dialyzing solution(with urea and excess ions)
Line fromapparatusto vein
Figure 25.9_1
Line from artery to apparatus
Pump Tubing made of a selectively permeable membrane
Dialyzingsolution
Fresh dialyzingsolution
Used dialyzing solution(with urea and excess ions)
Line fromapparatusto vein
Figure 25.9_2
1. Explain how bear physiology adjusts during dormancy.
2. Describe four ways that heat is gained or lost by an animal.
3. Describe five categories of adaptations that help animals thermoregulate.
4. Compare the osmoregulatory problems of freshwater fish, saltwater fish, and terrestrial animals.
You should now be able to
© 2012 Pearson Education, Inc.
5. Compare the three ways that animals eliminate nitrogenous wastes.
6. Describe the structure and functions of the human kidney.
7. Explain how the kidney promotes homeostasis.
8. Describe four major processes that produce urine.
9. Describe the key events in the conversion of filtrate into urine.
10. Explain why a dialysis machine is necessary and how it works.
You should now be able to
© 2012 Pearson Education, Inc.
Figure 25.4_UN01
Figure 25.UN01
35 33C
2730
20
10 9
18
Figure 25.UN02
FreshwaterFish
Osmosis
Gain Water
Drinking,eating
Saltwater Fish
Land Animal Evaporation,urinary system
Drinking Osmosis
Excretion Pump in
Excrete,pump out
Lose Water Salt
Figure 25.UN03
Urea
Figure 25.UN04
Kidney
Ureter
Bladder
Figure 25.UN05
Homeostasis
involves processes of
(a) (b)
(d)
animal maybe
maintainsbalance of
water andsolutes
humankidney
both done by
(c)
involvesremoval of
nitrogenouswastes
(e)
(f)
(g)
form may be
depends on
reproduction(where embryo
develops)
(i)
may be
endotherm
mechanismsinclude
requirementsdepend on
mechanismsmostly
(h)
heatproduction, insulation,
countercurrentheat exchange
ocean, freshwater,land
Figure 25.UN06
(a) (b)
Bowman’scapsule
From renalartery
To renalvein Glomerulus
Tubule
CapillariesLoopof Henle
(d)
(c)
Collectingduct