Coordination and Control Within a Body Endocrine system: transmits chemical signals (hormones) to receptive cells throughout body via blood –Slow.

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


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)

11

12

What is thermoregulation?

• Maintaining of internal temperatures in an organism

• Two major classes of organisms: endotherms and ectotherms

12

Are these endotherms or ectotherms?

• ENDOTHERMS

13

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

14

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

15

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

17

Comparing the energy expenditures in various sized endotherms and ectotherms• Observations:

18

How does the size of an organism affect is metabolic rate? (Comparison of various mammals) • Observations and Predictions

19

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”)


25.3 Thermoregulation involves adaptations that balance heat gain and loss

• Five general categories of adaptations help animals thermoregulate.


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.



• Insulation is provided by– hair,– feathers, and– fat layers.



• Circulatory adaptations include– increased or decreased blood flow to skin and– countercurrent heat exchange, with warm and

cold blood flowing in opposite directions.



• Evaporative cooling may involve– sweating, – panting, or– spreading saliva on body surfaces.



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.



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


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.



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

http://www.biology.ualberta.ca/facilities/multimedia/uploads/zoology/counter%20current.html

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

http://www.biology.ualberta.ca/facilities/multimedia/uploads/zoology/counter%20current.html

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?


Figure 40.19

Observations:

OSMOREGULATION

AND EXCRETION


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



• 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.



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.



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.


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.



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.



25.5 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.


• Ammonia (NH3) is– poisonous,– too toxic to be stored in the body,– soluble in water, and– easily disposed of by aquatic animals.



• Urea is– produced in the vertebrate liver by combining

ammonia and carbon dioxide,– less toxic,– easier to store, and– highly soluble in water.



• 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.



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.


• 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


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.


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


Bowman’s capsule

Fromrenalartery

Figure 25.7_2


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


Figure 25.7


Urine

To renal vein

Filtration

Nephron tubule

Capillary

Interstitial fluid


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


• High NaCl concentration in the medulla promotes reabsorption of water.

25.8 Blood filtrate is refined to urine through reabsorption and secretion


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


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


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


• 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


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


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


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

Coordination and Control Within a Body Endocrine system: transmits chemical signals (hormones) to receptive cells throughout body via blood –Slow.

Documents

heat gain

organisms metabolic

metabolic rate of organisms

external tempgenerate

environmental tempget

skin andcountercurrent

characteristics of endotherms

body temperature of