lecture 6 animal Flashcards
animals either regulate their what - or allow their bodies to do what
give example of each
animals eithe rregulate their physiological parameters or allow bodies to conform to external conditions
river otter – internal energy stays relatively same regardless of outside temperatruwe
bass – mimics temperature outside the body
what do regulators do
use homeostatic mechanisms to control internal changes
what do conformers do
allow their internal condition to change in response to external changes
what environments do conformers tend to live in
tend to live in environments that do not flucxtate and remain the same –
conformers tolerate what (thinkparameters)
greater ranges for physiological parameters
what physilogical paramters are being regulated
thermoregulation – osmoregulation
thermoregulation
temperatrue
osmoregulation
body water, and solute concentration
thermoegulation is the maintenance of
internal temperature within a tolerable range
why does body temperature matter
- biochemical and physiological processes are sensitive to changes in temperature
- each animal species has an optimal internal temperature range
– can be narrow or wide
examples of biochemical and physiological processes relative to changes in temperature
- enzyme reaction rates will slow down as temperature decreases
- proteins can denature when temperature increases
- membrane fluidity can vary with temperature
what happens when temperature is outside og range
impairs the functioning and can lead to death
what two things can body temperature be
`variable or relatively stable (poikilotherm – variable) (homeotherm – stable)
body temperatures of poikilotherms
varies with environment
homeotherms have a relatively
constant body temperature
thermal strategies can be defined based on
source of heat – endotherms and ectotherms
endotherms
rely on metabolism as their major heat source (internal)
ectothermsq
rely primarily on external enviornment as their major hear source – dont produce enough intwrnal body heat – rely mostly on their behaviour
some endotherms are __ and some ectotherms are __
endotherms – poikilotherm
ectotherms – homeotherms
endotherms – poikilotherm
animals that undergo hibranation – use internal body heat but can withstand different environments – redsucing metabolic processes
ectotherms – homeotherms
tropical reptiles – can only survive where area does not fluctuate in temperature – rely on external source (cannot live in variable temp)
thermoregulation requires maintiaing
equal rates of heat gain and heat loss
how does animal thermo regulate loss vs hain of heat
anatomical / physiological processes and behavioural responses
examples of anatomical / physiological process
evaporate heat loss
circulatory adaptations
metabolic heat production
insulation
evaporated heat loss
water is lost from moist surfaces – cooling body down
- adaptations that augument cooling - sweating and panting
– want to cool down – splash water on face – water evaporates – skin is cooled
circulatory adaptations
vasofregulation and countercurrent
vasoregulation
common to both ectotherms and endotherms – vessel regulation – acieved through nerve impulses and hormones – vasodilation and vasoconstriction
vasodilation
relaxes smooth muscle walls of surface blood vessels – allows more blood to flow from core to surface for cooling (why face ge3ts red when hot) – outside temperature allows skin to cool
vasoconstriction
tenses smooth muscle walls of surface blood vesssels – reduces blood flow from core to prevent heat lost – only goes to important parts of body that need to function when cold (brain, organs..)
countercurrent heat exchanges
heat is transferred between fluids flowing in opposite directions
- heat from warm artery (arterial blood) transferred to cool vein (venous bllood) – then returns to body’s core– because of close proximity
metabolic heat production three main parts
metyabolic activity produces heat, muscle contraction, brown adipose tissue
metabolic heat – muscle contracton
shivering and activity – shivering warms you up – activity warms ypu up
brown adipose tissue
high concentration of mitochondria – thriough cellular respiration heat is produced instead of ATP
hypothalamus thermostatic fnction regulation negative feed back both when body temp increases
your hypothalamus is the thermastat, internal homeostasis temperature is around 36-38ºC – when body temp increases, hypo will sense this. it will send signals to surface cells to produce sweat for water evaporation to cool down and will also send signals to the blood vessels to dilate – bringing blood to surface of skin and having external temperature cool it down – this will return it back to homeostasis
hypothalamus thermostatic function regulation feed back when body temp decreased
again thermostae is hypothalamus, when body temp decreases hypothalamus will sense this. willsend signals to muscles to contract (shiver to wamr body up) as well as will send signals to blood vessels to constrict – allowing blood to only go to important parts of body that need to be warm
insulation
fur feathers and fat – adaptation to preventt heat loss in animals and birds – traps layer of air between skin and fur – airm warms up due to proximity 00 heat remains closer to skin
behavioural responses
shade seeking, sun basking, migration
osmoregulation is the control of WHAT and the balance of WGHAT
control of solute concentrations and balance of water gan or loss from body
physical parameters of osmoregulation
body water (volume) – in blood, intersitial fluid, within cells
total solute concentraton – sum of all soluteds calcium, potassium ..
individual solute concentrations – calcium vs potassium – diff parts of body have diff concentrationd
osmosis
movement of water across selectively permeable membrane (from high concentrations of water to low concentrations of water)
hyperosmotic solution
higher solute concentration – lower free water concentration
hypoosmotic solution
lower solute concentration – higher free water concentration
selectively permeable membrane
only allows wate rthrough
animal cells are affected by the relative
osmolarity of their surrounding fluid
hyperosmotic fluid cell example
red blood cell in fluid that has hifgher conentration of solutes (hyperosmotic fluid) water from cell leaves through osmosis to try to balance concentrations – cell sshrivels and dies because lose too much water
hypoosmotic fluid cell example
red blood cell is placed in fluid with lower solute concentrations than within cell (hypoosmotic fluid) water from fluid will flow into cell to balance concentratins – bursting the cell
isoosmotic fluid cell example
both the fluid and the blood cell have the same amount of solute concentration therefore it is balance and no net movement of water is coming in or out the cell
animals maintain water balance in two ways
osmoconformers and osmoregulators
osmoconformers
are isoosmotic with their environment – they conform to environment in which they are in – no tendenct to gain or lose ater – are all marine – some have stable osmolarities while others tolerate variable osmolarities
– to ensure equal concentrations of solute ATPis used to activeyl transport specifric solutes to maintain homeostasis
osmoregulators
maintain a stable internal osmolarity – found in marine, freshwater, and terrestrial environments – particukar internal osmolarity is achieved by actively transporting solutes in and out of cells – water follows in response
osmoregul;ation requires..
energy
energy costs are reduced by
minimizing osmotic differences between body fluids and surrounding environment – freshwater molluscs have lower internal osmolarities than do marine molllucsc
why arent all animals osmoconformers
because they access more niches – benefits outweigh costs
the osmotic challenge faced by osmoregulators depends on their
environment
body fluids of most vertebrates
~300
freshwater lake/pond fluid
20-40se
seawater fluid
1000+
fresh water osmoregulators gain or lose
gain water – natural tendency to gain water bc of difference in osmolarity
marine osmoregulators gain or lose
lose water – too salty outside
terrestrial animals gain or lose
lose water – evaporated processes
marine fisah are what relative to sea water
hypoosmotic – meaning seawater has higher solute concentration
step 1 osmoregulation marine fish
osmotic water is lost through gills and other parts of body surface – but now fish loses water internally – how does it replace water
step 2+3 osmoregulation marine fish
to recoup for the water loss fish drinks lots of seawater – but also obtains salt ions
– another way is that they get water from food too – but also obtain salt ions
– how does it get rid of the excess salt
step 4+5 osmoregulation marine fish
excretion of salt from the gills through Cl- cells as well as excretion od salt and small amounts of water throuhg urine
freshwater fish are what relative to llake / river
hyperosmotic meaning it has higher solute concentration within it than water
osmoregulation freshwater fish step 1
have to gain water to decrease internal osmolarity – does this by gaining water through gills and other surfaces and someee ions and water from food – drink hardly any water
osmoregulation freshwater fish step 2 3
freshwater has to excrete excess water but also take up salts to maintain balance – uptake of salt ions by gills through Cl- cells and excretion of large amounts of water in dilute urine – also some salt lost though
dehydration is a challenge for terrestrial animals – adapations to reduce water loss
body coverings – shells, cuticles
nocturnal - limit their time in hot environments (daytime) to prevent sweating and loss of water
how do terrestrial animals maintain water balance
by drinking and eating moist food and by producing metabloic water through cellular respiration
animals control the solute concentration of an internal body fluid via
transport epithelia
what are transport epithelia
one or more layers of epithelial cells specialized for mocving particular solutes in controlled amounts in specific directions – active transpot (facilitated diffusion) or passive transport (simple diffusion and/or facilitated
transport epithelia have large surgface areas
some face external environment directly (gills)
– many line tubular networks connecting to outside by by opening on body surfaces – salt glands or kidneys
transport epithelia are closely connected to
circulatory fluid
how do seabirds sea turtles and marine iguanas remove excess salt
salt excreting glands
salt glands have transport epithelia that rely on +process
countercurrent exchange
– salt concentration is always higher in blood vessel than secretory tubule – throiugh secretory cell solutes will transport to secretory tubule – will eventually make its way to outside of body (blood and salt movement are in opposite directions
