Animal Physiology Flashcards
what is the difference between acclimatization and acclimation
acclimation is from an experimental climate change where as
acclimatiation is from a natural response
define plasticity
ability of living organisms to change their state in response to stimuli occurs at many levels from molecular to behavioural
at high altitude there is ____ barometeric pressure and ___ atmospheric oxygen
low
low
how many binding sites does haemoglobin have?
16
most people have between ____ and ___ % saturation in their red blood cells
96 and 100%
in the lungs hameoglobin has _____ affinty for oxygen because the oxygen saturation is very _____
high
high
what is the effect of altitude on oxygen saturation in the red blood cells? what does this lead to ?
partial pressure lower, haemoglobin has a lesser affinity for oxygen
leads to hypoxia - breathless and fatigued - body tries to reduce oxygen usage and increase oxygen intake
describe the andean and tibetan populations inn terms of altitude and time lived thert
andeans 4000 meters for 13,000 years
tibetans 4000 meters for 25,000 years
what three questions do we ask about the tibetan vs andean populations at altitude
same physiological adaptations?
are these heritable?
does the response influence fitness?
what is erythrocytosis?
an increase in the amount of red blood cells
in which population (tibetan or andean) saw erthocytosis?
Andeans had a higher concentration of haemoglobin at high altitude than low altitude
no difference in the tibetan populations
at high altitudes the populations had lower _____
oxygen saturation
the tibetans dont have more hameoglobin so what do they do to tackle their high altitude living? what advantage is there to this?
much higher respiration rate
- more nitric oxide - causes vascodialation which enbales the arteries to carry more oxygen
what is a disadvantage to the higher {Hb} in the tibetans?
more viscous blood and hencce a strained heart
Is high [Hb] heritable?
high heritbility in both populations
is oxygen saturation heritable?
NOT IN ANDEAN
heritable in tibetan
what type of gene for oxygen saturation?
dominant autosomal
- confers 5-6 oxygen saturation
give the values that: - temperture blood sugar pH water oxygen levels should be maintained at
37.5 degrees
0.1% blood sugar
pH 7.4
salt solute levels
96-99%
feedback systems start with a ____ which are monitored by a ___ then fed to a ________ which sends an impulse to the _____ which will alter the ______
stimulus receptor control centre effector stimulus
which part of the brain maintains temperture?
hypothalamus
give an example of a positive feedback loop in mammals
oxytocin stimulates contractionns
contractions stimulate oxytocin release
needs a control stimulus to stop release = giving birth
humming birds body temperture is 38-40 degrees in the day and 18-20 at night they acheive this by?
going into a state of torpor - a slowing down
in torpor body temp maps onto ______ temp. in humming bird torpor heart rate went from ___ to ___
600 to 50
when hibernating heart beat becomes _______ and ______
irregular and slows down
describe the use of EPO - erythropoietin
blood oxygen falls kidney detects it and releases EPO
stimulates red bone marrow to release RBCs which will increase the oxygen saturation
produced naturally at high altitude (heavy excerises and when haemoraging)
what does EPO increase the risk of?
heart attacks and strokes since blood thickens therefroe heart must work harder
if EPO is naturally occuring then how is it noticed in doping tests?
frequent testing works out the baseline levels - test before competition to see if there is a spike
what does meldonium do?
what is it used to treat?
increases blood flow
increases flow of oxygen
used to treat coronory heart disease
because they experince _______ larger animals tend to be slower moving
greater gravitational forces
what is allometry
study of differenital growth - how parts of the body scale with body size
three types of allometry
ontogenic allometry - body proportions change during growth
static - body proportions differ between individuals of same sex abd age within a species
isometric - body proportions stay the same
what is the equation that demonstrates the allometric relationoship
y=ax^b
y=size of body part
x = measure of whole body size
a = an intial growth index
b = scaling exponent
for different values of b (scaling exponent) describe how body parts grow in relation to body size
b=0 is no relationship
b=1 part proportional to size
b<1 body part slower than body growth
b>1 body part grows faster than body growth
in male stag bettles mandibles growth is _________ , but is _______ in females
positive allometry males
isomeric in females
why is isometery not common
small animal can maintain its weight on a small limb
body grows volume increase more rapidly than surface area
mass increases more rapidly - square cube law
if growth doubles in isometry
- mass increases by 8 times a with only a 4 fold increase in surface area to support it
equally 8 times more respiring tissue with 4 times greater surface area for respiration to occur across
endotherms have a ______ metabolic rate than eectotherms
higher
metabolic rare =?
body weight ^0.75
mass specific metabolic rate =
metabolic rate /weight =weight^0.25
give the proportional heat lsot from each of the heat exchange processes
radiation - 60%
conduction - 3%
convection -15%
three methods of minimsing heat loss
reduce SA:v
alter temp gradient
insulation
describe a behaviour used by the bullfrog to reduce convection
covers itself in mucus
pros and cons of ectotherms
5 x slower metabolic rate
less water
larger proportion of energy to reporoduction
good colonisers
but
cant be nocturnal
cannot sustain high activity
cant live in colder environments
what is the thermal neutral zone?
range of temps where no energy is needed to maintain body temperutres
- upper and lower crictical limit
how does vascoconstriction effect regulation of body temperture
decreased diameter of blood vessels blood flow to skin decreases skin cools less heat lost heat trapped in body core reduces conduction and convection
how does shrivering increase temperture
uses ATP to cause body movements and therfore increases heat
adrenalines role in heat exchange
released from adrenal medulla increases heart rate to increase heat
thyroxine role in heat exchange
released from thyroid gland increases basal metabolic rate
why does brown fat increase ability to insulate ones self? where is it most common
brown fat rich in mitochondria - break down fuel into energy
found in new borns and hibernating mammals
describe countercurrent heat exchange
blood in hot artery flows by colder veins and exchanges heat. cold blood does not return to the heart
what is another name for ectotherms
poikilotherms
another name for endotherms
homeotherms
what is blubber
thick layer of vascularized adipose tissue under the skin of sea mammals
gular fluttering
rapidly flap membrane in the throat to increase evaporation
urohydrosis
deficate on legs for evaporative cooling
hypothermia
too cold
hyperthermia
too hot
which hormone triggers sweating
adrenaline
where can the hypothalamus send messages to about increasing temp
smooth arteriole sweat glands arrector pili muscle in skin skeletal muscles adrenal and thyroid glands
four factors that effect diffusion
temperture
particle size
electrical charge
concentration gradient
define osmolarity
measure of osmotic pressure exerted by a solution across a perfect semi permable membrane = number particles divided by the number of molecules x concentrations
define tonicity
effect of a solution on a cell volume
what is an osmoregulate
kepp internal osmolarity of boyd fluids with differing environmental osmolrity
what is an osmoconformer
internal body fluids match the external envirnoments
the marine teleost is ______ to the environment. which means it…
hypoosmotic
loses water to the environment
the marine teleost takes in large amounts of water and thus brings in lots of salt how does it tackle this?
active transport of salt out of the cells
- many Na/K pumps on basolateral surface of gill membrane - huge sodium gradient in chloride cell
- cl- transported using Na+
gradient - (cl-/Na+)
- cl- builds up and diffuses out
- na+ follows Cl- charge by smeaking through leaky tight cell junctions
also only excretes small amounts of concentrated urine
the freshwater teleost is ______ to the environment
hyperosmotic
freshwater teleosts are hyperosmotic to their environment which means they lose large amounts of salts how do they tackle this
active tack up of salts through gills
at apical surface ATP used to bring in chlroide and sodium (symporters pump chloride into the intra cellular tissue)
- Na+ follows chlorine gradient into the body
- very tight , tight junctions hence no ion leak
what is formed by breakdown of proteins and nucleic acids?
toxic ammonia which raises the pH of body fluids
- disrupts homeostasis and key enzymes
three methods of removing nitrogenous wastes and whuch organisms use them
ammonia - aquatic organisms
urea - mammals
uric acid - birds and reptiles
describe waste removed as ammonia
bony fishes and aquatic amphibains
- very little energy needed
small molecule hence rapid diffusion
- but very toxic therefore cant build up
urea as a waste remover
mammals amphibians and cartilagnous fishes
1000x less toxic than ammnoia
- requires less water
but requires 1.5ATP used to convert every 1 ammonia to urea
uric acid as a waste remover
birds insects reptiles
completely insoulable so has no effect on water potential
- nor pH
- less toxic than urea
- excreted as semi solid - good for water conservation
but requires 3 times more energy to produce than urea
in what types of organism is uric acid especially useful?
egg layers
- urea would build up to toxic concnetrations inside impermeable egg
describe waste removal in frog life history
excrete ammonia as tadpoles
become frogs and excrete urea since water acsess has decreased
how do protazoa deal with nitrogenous waste?
expel water into the environment with it comes nitrogneous wastes
describe waste removal in the lung fish at two points ini its life history
aquatic - pond dry out it covers itself in mucus cocoon.
excretes urea in dry phase but ammonia when in water
what organ is used by annelids and moluscs to remove waste
the nephridia
insects use the _________ for waste removal
malpighian tubule
why do insects secrete waste as uric acid
to conserve water
describe malpighian tubules
blinf ended
one cell thick
between midgut and hindgut
float in haemolymph
how does the malpighian tubule work?
salt water and nitrogenous wastws are actiely transported into the tubules
net movement of water into tubules
products move into the gut and out of the rectum
kidney recieves _____ % of bodies cardiac output
20-25%
what are the four stages of waste removal in the kidney
filtration
reabsorbtion
secretion
excretion of filtrate
where does ultrafiltratuion occur?
renal cortex
what is the role of the renal medulla
regulates water and salt in blood
describe the process of ultrafiltration
blood pressure in glomerulus forcecs fluid into the lumen of bowmans capsule
fluid contains small solutes
non selective filtration
what occurs in the proximal tubule
water and salt reabsorbed from gromelular filtrate
what happens in the decending loop og henle
water leaves filtrate
what happens in the accednding loop of henle
salt leaves filtrate
- it is impermable to water
what happens in the distal tubule
regulates salt concentrations
regulates pH
water balance
describe the countercurrent muliplier system in the kidney
osmotic gradinent down loop of henle
- fluid in descending limb flowing in the opposite way to the ascending limb
- fluid in tubule in desending limb flows in opposite direction acending limb
describe the homestatic control of nephron permability
increased osmolarity of extra cellular fluids
- osmoreceptors
- hypothalamus
- vasopressin and andtidiuretic hormone is released
- which increases water permeability of the distal tubule and collecting duct
what are the two strategies to living in extreme tempertures?
tolerate
avoid damage
how do heat shock proteins work?
promote proper refolding of proteins that have been denatured
prevent damage interactions with proteins
aid in disassembally or formation of proteins aggregates
heat shock proteins are themselves proteins, how do they not denature
stronger H bonds
more h bonds
better able to hold primary structure
harder to denature
how are heat shock porteins used by the immune system ?
cell breaks found in extra cellular fluid and body knows something is up
what is supercooling
water requires a nucleate to freeze
remove any ice nucleating agents
no nucleating agents ice can be cooled to -42 degrees without freezing
describe cryoprotectant synthesis
alternation of biochemistry
increased solute concentration so decreased freeezing point
most common = glycerol which reduces the amount of ice formed outside of the ccell - stops water molecuels leaving
supercooling and cryoprotectants are examples of _____ and occur more in the ______
freeze avoidance
occur more in northern hemisphere
three methods of freeze tolerance
limit supercooling by initiating the freezing of body fluids - control where ice is formed
produce ice structuring proteins - antifreeze, change strutuer fo ice bind to small crystals to stop them growing any larger
ice nucleating proteins - avoids sudden freezing
how does the arctic wolly bear mpth tolerate -70 tempertures in annual diapause
accumulates glycerol and betanine in late arctic summer
formulates hibernaculum to elimainate nucleators
how does the snow flea dela with extreme cold
synthesises an antifreeze protein - rich in glyceine
- used for storage or donor organs in medical setting
rate of diffusion =
(differnce in partial pressure x surface area x temperature x solubility) / distance x sqrt of molecuar weight
insects use tidal ______. what is this?
ventilation
gases exit and enter the same way
fetal haemoglobin has a _____ affintiy to oxygen
higher
describe the inhilatinos and exhilations of a bird
first inhilation moves air through trachea into prosterior sacs which expand
exhale and move air into lungs
inhale air from lungs to anterior sacs
exhale again and ir goes into trachea and back out of the body - flow is unidirectional
why do birds need their adaptaions to breathing?
altitude and flight
- lower oxygen partial pressures
- lungs small for boy size - high metabolic demands
intercostal muscles ___ as well as diaphragm cauysing pressure to _____ and air moves in
contract
decrease
what is the residual volume
the air left in the lungs after exhilation
marine mammals can store oxygen in the _______
muscles
how is the level of CO2 maintained in animals
CO2 level rises
sends message to chemorecptors
then to medulla
increased breathing rate which lowers CO2
currently ____ of brid species are experiencing higher temps than their max which is predicited to rise to ___ by 2080
for mammals this is _____ to _____
15%
36%
16%
47%
