Presentation FISWAN

8/9/2019 Presentation FISWAN

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Thermoregulation

Insulation

Metabolic heat

production/physiological

thermoregulation

Countercurrent heat

exchangeBehavior


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Physiological thermoregulation

Altering metabolic generation of heat to

regulate temperature

Ex: Metabolism increases to raise internal

body temperature in a colder environment


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Regulation of body temperature

Cold blooded

PoikilothermicPrincipal source of heat is

from the environment

warm blooded

Homeothermic

Principal source of heat is from their own

body through metabolic activity


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Countercurrent Heat Exchange Warm and cold blood flow in

opposite directions to regulatethe temperature (arteries and

veins)

Usually around the brain/headregion

Leatherback Turtle, Sea Gull


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Homeotherms and Poikilotherms

Vertebrates (birds,mammals,reptiles &

amphibians)

Tb = body temperature

Ta = environmental temperature


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Homeotherms

warm-blooded animals- birds &

mammals

Maintain constant Tb

Endothermic (metabolism is source

of body heat)

Normal Tb range is 35-42 degrees C


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Poikilotherms

cold blooded animals (reptiles,

amphibians, fish, insects, etc)

Tb fluctuates greatly Rely on environment for much of their

Tb (ectothermic vs endothermic)

Must warm up; act like a black box


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Muscle tissue & many other body functions & biochemicalMuscle tissue & many other body functions & biochemicalreactions work best at constant, warm temperature (aroundreactions work best at constant, warm temperature (around37C)37C)

PoikilothermsPoikilotherms: (fish, amphibians, modern reptiles) low ability: (fish, amphibians, modern reptiles) low abilityto control internal temperature,to control internal temperature, intint temp similar to ambienttemp similar to ambienttemp, can only be active in warm conditionstemp, can only be active in warm conditions

Control temperature by behaviour (e.g. basking, sheltering)Control temperature by behaviour (e.g. basking, sheltering) PoikilothermsPoikilotherms restricted to tropics, subtropics in generalrestricted to tropics, subtropics in general Only one genus of lizard north of theOnly one genus of lizard north of the PyreneesPyrenees in Europe (in Europe (LacertaLacerta))

ThermoregulationThermoregulationPoikilotherms & HomiothermsPoikilotherms & Homiotherms

Lacerta viviparaLacerta vivipara (Wall Lizard, UK)(Wall Lizard, UK)

baskingbasking


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HomiothermsHomiotherms: Maintenance of constant body temperature (some: Maintenance of constant body temperature (somedinosaurs, birds & mammals): heat derived from respiration reactiondinosaurs, birds & mammals): heat derived from respiration reaction

CH2O + O2 > CO2 + H2O + energy (can be stored as fat to burn later)

Efficient circulatory system and fourEfficient circulatory system and four--chambered heart. Enables warmedchambered heart. Enables warmedblood to travel to all tissues and maintain internal body temperature.blood to travel to all tissues and maintain internal body temperature.

Fur or feathers (modified scales) to prevent heat lossFur or feathers (modified scales) to prevent heat loss

AdvantageAdvantage: animal can be active day & night, in climates with severe: animal can be active day & night, in climates with severewinters (winters (poikilothermspoikilotherms restricted to tropics, subtropics in general)restricted to tropics, subtropics in general)

DisadvantageDisadvantage: heat energy must come from food: heat energy must come from food -- higher energy intakehigher energy intakerequired a small mammal is always only half an hour from deathrequired a small mammal is always only half an hour from death --endothermsendotherms need constant food supplyneed constant food supply

The high diversity (and lack of extinctions) in Aust lizards may be becauseThe high diversity (and lack of extinctions) in Aust lizards may be becausetheir lower energy requirements enable them to survive droughtstheir lower energy requirements enable them to survive droughts(prolonged periods with little food) more easily(prolonged periods with little food) more easily

ThermoregulationThermoregulationPoikilothermsPoikilotherms && EndothermsEndotherms

Thorny devil


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Thermoregulation of Mammalia

These animals belong to a group of amniotes

known as the synapsids.

An adaptive radiation of mammals followed theextinction of the dinosaurs. There are about

4,500 extant species.

Evolution. Mammals are believed to have

evolved from mammal-like reptiles

(therapsids)


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Carnivores eat mostly fleshCarnivores eat mostly flesh

Insectivores eat insectsInsectivores eat insectsHigh energy, easy to digestHigh energy, easy to digest

Short, simple gutsShort, simple guts

Well developed canine teethWell developed canine teeth

Mammals are diverseMammals are diverse

Insectivore

www.earthlife.net/mammals/images/anatomy/teeth.jpg


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Insulation

Fur

Feathers

Blubber

Coloration


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Metabolic Activity Shivering

Panting

Evaporation of water

from respiration

and/or sweating


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Adaptations for Cold Conditions:

avoiding Hypothermia

Hibernation (also has physiological &behavioral aspects to it) Allow Tb to approach Ta

True hibernators: marmots, ground

squirrels, bats

Partial hibernators:

bears, hummingbirds

(at night)


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Cool it!

Rolling in mud

Taking a dip or standing in the water

Going underground or lying in the shade

Flying in high altitudes


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The Class Reptilia

The amniotic egg allowed for independence from water

for reproduction. The amniotic egg has a tough shell

and extra embryonic membranes. In addition

reptiles have waterproof skin (scales with keratin)and use thoracic breathing (unlike the buccal

breathing of amphibians); no cutaneous respiration

except for some turtles using moist surfaces of the

cloaca.


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THERMOREGULATION OF REPTIL


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Early line of evolution.Early line of evolution.

PoikilothermicPoikilothermic (restricted to(restricted to tropics,subtropicstropics,subtropics)) TurtlesTurtles -- marine (flippers)marine (flippers) TortoisesTortoises land (feet)land (feet) SkinSkin -- Protective armour:Protective armour:

dorsal shielddorsal shield carapacecarapaceventral shieldventral shield plastronplastron

..

ReptilReptil

TortoiseTurtles


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Crocodiles, caimans (crocodilians) and alligators.Crocodiles, caimans (crocodilians) and alligators.

Australia has two species of crocodile:Australia has two species of crocodile: CrocodylusCrocodylus johnstonijohnstoni

(freshwater) and(freshwater) and CrocodylusCrocodylus porosusporosus (saltwater(saltwater more dangerous,more dangerous,

larger).larger).

PoikilothermicPoikilothermic -- restricted to the tropicsrestricted to the tropics

SaltwaterSaltwater

FreshwaterFreshwater


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Thermoregulation of Aves


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Adaptations for Cold Conditions:

avoiding Hypothermia

On land, breeding season, bulls haul out on

Pribilof Islands,Alaska

y territorial defense= heat production

y in water, heat lost easily, not in air on land

ybreeding activities fall off once TA reaches

y54 degrees F.

y flippers- a thermal window


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Adaptations for Hot Conditions: avoiding

Hyperthermia

Birds

y

Pre-adapted for hot climates-high TB(4-5 F higher than mammals)

y Most birds are neither nocturnal norfossorial, so must meet the environment

head-on.


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Adaptations for Hot Conditions: avoiding

Hyperthermia

Structural adaptations:

yFur and feathers- same idea as hypothermia

except that you want to reduce air space

y Thermal windows: Bare places on skin-

mammals--face, feet, arm pits, belly

birdsgular pouch, feet, legs, face


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Thermoregulation

Behavioral traits

Physiological traits

Global warming andhabitat shifts

Fish gill arch showing interface

between blood and external

environment


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Adaptations forswimming

Adaptations for

dispersal

Movement and dispersal

Larval blue crab

Ekman spiral


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Amphibia

a. Amphibia produce the

heat and for the biggest

loss the heat with faster by

evaporation.

b. Adaptation behaviour

possibility amphibia formaintain the temperature

of the body.

a. Amphibia include in animal

poikiloterm land

b. The temperature of body

defi ited by by the balance

with condition of

enfironment temperature


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Order Anura


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Invertebrata

Have control of the temperature of body but

between the other adapt the temperatur of

body by physiology.

Some species have power heat internal and

the characteristic is endotermic.


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Apache cicada

Sonoran desertDicerooproctoa apache

Among the loudest insects on record Sings when TA 40oC in shade

Keeps cool by evaporative cooling from

fluid shed from dorsal pores Extravagant water loss for desert insect

made possible by xylem feeding

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