Samenvatting
Summary Adaptive and stress physiology
This summary contains all the needed information for this course. Including the animal part of prof. Temmerman and the plant part of prof. Rolland
[Meer zien]Voorbeeld 3 van de 23 pagina's
Voorbeeld 3 van de 23 pagina's
In winkelwagen
Voorbeeld van de inhoud
Laura van den EndIntroduction
Stress: anything that changes the homeostatic state Neuro-adrenal responses
- Neural and endocrine signaling regulate the
response (not necessary specific)
- Responses can also be on something that is good
for an organism → eustress is the “good” stress
General adaptation syndrome
Alarm phase (very short)
- Homeostatic level is specific for diff organisms
- The baseline will be affected: shock (resistance ↓)
→ counter-reaction (fight to flight response)
- Alternative: tend and befriend = trying to accu- - CRH: produced by hypothalamus (senses stress
mulate stress in your life, switch lifestyle to levels) → local in the brain → activate pituitary →
prevent fighting or flighting ACTH release → stimulates adrenal gland →
glucocorticoids release (in cortex of adrenal gland)
- Catecholamines: A and NA -. Set the body in state
Resistance phase
- High E cost → at some point there will be no E left of alertness
- Relocation of sources (immune system, repro- - AVP: can also be OT (tend and befriend)
- Alarm phase: Sympathic NS; Cortisol, A etc ↑;
ductive system/drive, GI system)
mobilize resources
- Resistance phase: Parasympathetic NS; blood
Exhaustion phase glucose, cortisol, adrenalin etc remain ↑; outward
- Relocation of recourses cannot occur forever normal appearance, but resources of the body
- Visible is sickness or exhaustion remain focused on dealing with stressor; HR, BP
and breathing remain↑ ⇒ body on ‘alert’
Adaptation - Exhaustion phase: bodily resources are expended;
susceptibility to disease ↑↑; if unresolved: lethal
Homeodynamics
- Homeodynamic space shrinks when aging → less
capable of dealing w stress. also improve dealing
with stress slows down aging = tight connection
- Lot of stressors come in combinations → cross
- Deal better with it in the next exposure protection: some responses are useful for different
- Entire level goes up vs stronger response kinds of stressors
- Damage is also possible instead of adaptation →
no response in next exposure
Dealing with stress
- Neuro-endocrino and immune systems
Physiological responses to stress - Stressor-specific responses: chaperones, signaling
and adaptation
- Conformers vs regulators:
1 bold dashed line (almost straight)
2 curvy dotted line
3 Dashed and dotted
4 is light dashed line (straight)
5 bold dashed line that stops (top)
6 continuous line
Adaptive and stress physiology
, Laura van den End
Temperature
- Different species heave different temperature Blubber and fur
requirements - 2 ways (autonomous NS)
- How an animal deals with stress also limits the nr 1. Insulation layer on the inside of the skin =
of environments it can migrate into (and the other blubber
way around) - Insulating value regulated by blood vessel
- Earths range: -89ºC - 350ºC; prokaryotes are shunting
everywhere 2. Insulation layer on top of the skin: fur
- Animal life is more restricted: in order to cool - Insulating value regulated by pilomotor
down, endothermic animals need to produce control
heat - Hair traps air → flattened fur has less
- Ectotherms are capable to live in colder insulating value than fur that stands straight
environments but not in hotter - Short term: orientation → volume of trapped air
changes
Metabolism - Long term: seasonal changes
- Metabolism generates heat (protons slipping out, - Migrating (local or long term)
instead of being used in the ATPases)
- The higher the difference, the higher the transfer Biochemistry
- K - thermal conductivity → Ek is passed on
between molecules Enzyme kinetics
- The closer together, the faster the transfer - Enzymes lower Eact, do not affect reaction speeds
- Conductivity of water is bigger than air: water is
but ΔG, T affects reaction speed
more dense → more molecules to exchange heat - At eq: fwd and rev speeds = no major effects
- Convection: helping conduction by replacing
expected over non-denaturing range, but biolo-
molecules
gical interactions: often fwd favored (and P often
- Radiation: electromagnetic, no direct contact
titrated away)
required. Using radiation from the sun to warm - Deadly if:
up (also loss of heat) - Reaction too slow to sustain life
- Evaporation: get rid of the heat (e.g sweating) - Misaligned reaction speeds between multiple
- Animal’s body temperature reflects stored heat →
enzymes
depends on surface to volume (T gradient and - Denaturing of enzymes
specific heat conductance) - Some enzymes have T-dependent allelic
expressions
Heat transfer: general mechanisms - Occurrence of alleles according to geological
location
Blood ow
- Redirection: more easily lose or gain heat Membrane uidity and remodeling
- Also countercurrent exchangers: eg feet of birds: - Membranes need to be fluid so proteins can move
feet are not endothermic but have T of environ- around → not too fluid bc then an organism can’t
ment → heat exchange between arteries and veins regulate the moving around of proteins
→ increase T in feet - Measure: DPH → intercalated into the membrane
- Tuna: most fish have blood vessels in the center, → apolar
but tuna has under their skin - Measure anisotropy → shine polarized light
- Blood cools down when traveling pastils → into membrane → DPH will return polarized
you don’t want the cool blood to travel to the light. If membrane becomes more fluid →
central parts of your body DPH can move around more → less polarized
- Counter Curren: cool blood (O2 rich( coming light will be returned
from rolls gets heated up by the warmer - The higher the anisotropy, the more rigid the
blood membrane → doesn’t matter which animal
you take, they will always try to keep their
membrane fluidity in a certain range
Adaptive and stress physiology
fl fl
, Laura van den End
Physiological classi cation
Homeothermic vs poikilothermic
- Poliko: Tb fluctuate with the changing of Tenv →
can’t maintain Tb of narrow range (cold blooded,
fish, amphibians and reptiles)
- Homeo: Tb do not fluctuate with the change of Tenv
→ can maintain Tb of narrow range (warm
blooded, bird and mammals)
Endotherm vs exotherm
- All animals produce heat (metabolism) →
ectotherms don’t use this heat (endotherms do)
- Move membrane to colder T (1 → 2) → membrane - Endotherm: generates internal heat to regulate its
becomes more rigid → after a while, membrane body temperature (not necessarily constant)
fluidity drops (2 → 3) = membrane acclimated - Ectotherm: environment determines the body
- Move membrane to higher T again (3 → 4) fluidity temperature (not necessarily variable)
will drop even further but will evt go back up (4 - Real life is between the extremes: ectothermic and
→ 1) = homeoviscous membrane adaptation homeothermic live in thermal stable environments
- Regulation towards low fluidity when T drops
- Regulation towards high fluidity when T increases Regional and temporal heterothermy
Temporal heterothermia → hummingbird
- FA chain length → shorter = fewer interactions - Needs to eat all of the time to keep
with neighboring molecules → higher fluidity metabolism going and thus regulate Tb
- Saturation: unsaturated bonds: next FA will be - What at night when they need to sleep?
pushed further away → higher fluidity → Tb drops to conserve energy
- Phospholipid class: PC (phosphatidyl choline) =
acc to warmer; PE (phosphatidyl ethalomine) = acc Regional heterothermia → bumblebees
to colder - TA = ambient temperature (outside)
- Cholesterol content: keeps long side-chains from - TB = body temperature
interacting with each other at lower T → rigid - Tb split over thorax and abdomen
membrane becomes more fluid bc FA chains can’t - Thorax = endothermic → bc thorax
interact with each other + restricts movement in is kept warmer than the env when Ta
membrane when T↑ → more rigid drops
- Abdomen = ectothermic → bc Tb follows Ta
- Cells do this via de novo synthesis, but also in situ ⇒ only regulation of thorax T by the animal
replacement
- In situ relies on FA from diet Flying insect + pre-flight thermogenesis
- De novo FA synthesis in ER: endo- and - Warmup time ~ Tenvironment
exocytic cycles: continuous replacement - flight muscles put in anta-
gonistic movement (same as
Chaperones shivering in humans) →
- Small molecules e.g. trehalose increase of thorax T makes it
- Proteins: heat shock proteins possible to fly (wings attached
to thorax) → other animals
can’t do this at lower T but
this organism can
Heterothermic fish: typically
species that swim continuously
- Animal has rete mirabile, red
muscle ⇒ heterothermic
- Major vessels towards outside
of body → doesn’t regulate T
⇒ ectothermic
Adaptive and stress physiology
fi
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
√ Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, Bancontact of creditcard voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper lauravandenend. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €5,49. Je zit daarna nergens aan vast.
Is Stuvia te vertrouwen?
4,6 sterren op Google & Trustpilot (+1000 reviews)
Afgelopen 30 dagen zijn er 52510 samenvattingen verkocht
Opgericht in 2010, al 14 jaar dé plek om samenvattingen te kopen