Resume
Summary Adaptive and stress physiology: Previous exam questions with answers
- Établissement
- Katholieke Hogeschool Leuven (UCLL)
This document contains previous exam questions with a very elaborated explanation and answers.
[Montrer plus]
Aperçu du contenu
Laura van den EndAdaptive and stress physiology
———————————————————————————————————————————-
Temmerman
———————————————————————————————————————————-
1. Hypoxia causes in animals an increase in oxygen binding capacity of haemoglobin
• False
• lowlander → to high altitude they increase the Hb capacity to deliver O2 to the right places = lowering affinity.
• Highlanders are adapted to hypoxic conditions and have an elevated [RBC] (bc of HIF-1 that promotes EPO
production)→ they have more Hb and have a greater carrying capacity of O2. They did not, however, increase
the affinity if Hb itself.
2. Hans Seyle could agree with the concept of hormesis
• True
• Hormesis: phenomenon that something that is bad for you in high dose, can be good for you in a low dose. It
keeps the body alert without exhausting it ~ eustress
• Seyle: founder of the general adaptation syndrome: consists of 3 phases: alarm, resistance and exhaustion →
describes the negative effects of chronic stress
• In the alarm phase, the stressor is noticed and the body experiences some shock → induces the fight or
flight response
• The sympathetic NS is active and cortisol and A levels rise (produced by adrenal gland, stimulated
by ACTH from pituitary gland after stimulus of CRH and VP from the hypothalamus = HPA axis of
neuron-adrenal response)
• In the resistance phase, de body stays focussed on dealing with the stressor (outside appearance is
normal, though recourses are used extensively)
• Parasympathetic NS is active and the levels of cortisol and A remain high → HR, BP and breathing
remain high
• The exhaustion phase occurs when the resistance phase takes too long or a new stressor induces a new
alarm phase without the time to recover from the first one. The recourses are depleted and the body is
e.g. more susceptible for diseases → can result in death if unresolved
• While Selye's emphasis was on the damaging effects of stress, he acknowledged the existence of adaptive
responses and the potential for beneficial effects in certain situations ~ in line with hormesis.
3. Hans Seyle zijn model bestaat uit drie fasen. →True (see Q2)
4. De hypoxia response kan ook in normoxia worden uitgelokt
• True
• Normoxia: O2 levels of the environment are normal for the animal - differs between diff species that live in diff
environments
• Hypoxia-inducible factor 1 (HIF-1) controls activation of hypoxia-sensitive genes
• Epo → stimulate RBC production
• VGEF → growth capillaries → more supply to tissues
• Glycolytic enzymes → more E without the need for O2
• HIF-1 is regulated:
• ↑[O2]: HIF-α is ubiquitinated by PHD → O causes hydroxylate cysteine branch of the response →
degradation by proteasome (happens in normoxia)
• At ↓[O2], harder for PHD to get by → HIF-α escapes hydroxylation → moves into nucleus to act TF →
promotes O2 response at genome level (happens in hypoxia)
• When HIF-1 is degraded in normoxic conditions, a feedback mechanism can occur where this degradation is
inhibited → hypoxic response
Adaptive and stress physiology — Examenvragen— 1/8
, Laura van den End
5. Vascular rete structure help actively moving animals retain heat. (Rate mirabile)
• True
• The vascular rete: countercurrent heat exchange system, a network of blood vessels found in animals that are
adapted to cold environments → conserve heat and prevent excessive heat loss.
• Warm arterial blood and cool venous blood flow in close proximity to each other, allowing for heat transfer
between the two.
• The warm arterial blood coming from the body core transfers heat to the cool venous blood returning from
the extremities → conserve body heat + keep vital organs warm
• Beneficial for actively moving animals (like some fish) because their increased muscle activity generates heat,
which can be lost through the limbs or extremities
6. The actogram of a per0 mutant would look the similar to that of a fruit fly kept in constant darkness.
• False
• per (period) gene: involved in the regulation of circadian rhythms in fruit flies. Per0 mutant → loss of circadian
rhythmicity.
• Actogram: shows activity of circadian rhythms (every 20-24h → activity after a cue (light))
• Circadian clocks have the characteristic that they run endogenously (without a cue). Taking away the cue has
the effect of a short or long running clock, where the activity occurs earlier or later resp. ≠ losing rhythmicity
• Losing rhythmicity can be caused by presenting the cue all the time
7. The concept of hormesis says that it is good that your tissues suffer from damage.
• False
• Hormesis: phenomenon that something that is bad for you in high dose, can be good for you in a low dose. It
keeps the body alert without exhausting it ~ eustress
• In this state the body is alert but not suffering
8. Seals can tolerate lactate so they can dive longer but they have to take a longer recuperation time.
• False
• Seals can not tolerate lactate
• In longer dives, the aerobic metabolism depletes O2 reserves → HIF-1 stimulates glycolysis → lactate
production
• [Lactate]↑ in longer dives when resurfacing → need to get rid off in the local muscles → into the blood so that
the entire body can detoxify → convert again into pyruvate and into the Krebs cycle (O2 is available again)
• The longer the dive, the longer the recovery → efficient to stay below the ADL (aerobic diving limit)→ able to be
longer under water in the long run
9. A human with non-functional melanopsin will deal with negative health conditions.
• True
• Light comes in through eyes (even when blind) → not by rods and cones but by retinal ganglion cells: some are
photo-sensitive → have their own opsin: melanopsin → plays a role in synchronizing the internal clock with the
ext light-dark cycle
• When the melanopsin is non-functional, light perception is decreased and the person will experience a more
dark/dark cycle which can result in seasonal affective disorder (SAD); mutation: pro10leu.
10. Thermoregulators always use more energy than thermoconformers.
• True
• Conformers: match inter and external environment, typically small animals without exoskeleton
• Regulators: internal environment remains constant, is very energy-costly, typically large animals
• Though all kind of combinations can be made
Adaptive and stress physiology — Examenvragen— 2/8
Les avantages d'acheter des résumés chez Stuvia:
Qualité garantie par les avis des clients
Les clients de Stuvia ont évalués plus de 700 000 résumés. C'est comme ça que vous savez que vous achetez les meilleurs documents.
L’achat facile et rapide
Vous pouvez payer rapidement avec iDeal, carte de crédit ou Stuvia-crédit pour les résumés. Il n'y a pas d'adhésion nécessaire.
Focus sur l’essentiel
Vos camarades écrivent eux-mêmes les notes d’étude, c’est pourquoi les documents sont toujours fiables et à jour. Cela garantit que vous arrivez rapidement au coeur du matériel.
Foire aux questions
Qu'est-ce que j'obtiens en achetant ce document ?
Vous obtenez un PDF, disponible immédiatement après votre achat. Le document acheté est accessible à tout moment, n'importe où et indéfiniment via votre profil.
Garantie de remboursement : comment ça marche ?
Notre garantie de satisfaction garantit que vous trouverez toujours un document d'étude qui vous convient. Vous remplissez un formulaire et notre équipe du service client s'occupe du reste.
Auprès de qui est-ce que j'achète ce résumé ?
Stuvia est une place de marché. Alors, vous n'achetez donc pas ce document chez nous, mais auprès du vendeur lauravandenend. Stuvia facilite les paiements au vendeur.
Est-ce que j'aurai un abonnement?
Non, vous n'achetez ce résumé que pour €5,49. Vous n'êtes lié à rien après votre achat.
Peut-on faire confiance à Stuvia ?
4.6 étoiles sur Google & Trustpilot (+1000 avis)
79202 résumés ont été vendus ces 30 derniers jours
Fondée en 2010, la référence pour acheter des résumés depuis déjà 14 ans