Lecture 15 (19)

Question 1

Why is Nutrition important?

Answer 1

Diet- paramount to health in humans/other animals
Resources from diet- used for immune response
Starvation/nutrient limitation can constrain immunity
Parasites ask use host resources- can change host requirement

Question 2

Give examples of what happens when resources are limited?

Answer 2

Starved mice + Tcells in both thymus and spleen decrease. Reduced immunity

Starved bees = reduced survival when challenged with parasites

Question 3

Does the source of energy affect parasite resistance?

Answer 3

Yes.

E.g caterpillars less likely to survive infection on low protein diets

Question 4

How can nutrition affect the outcome of parasitic infection?

Answer 4

Providing the immune system with nutrients required to work effectively

Changing the hosts ability to tolerate infection

Question 5

How does self medication work in animals?

Answer 5

Specific nutrients rather than energy content affects immunity/parasite success
Infected hosts should seek out diet that gives the best chance of survival

Question 6

Define therapeutic self medication

Answer 6

A specific therapeutic and adaptive change in feeding behaviour in response to disease or parasitism
- behaviour should be…
Increase fitness of infected
Decreased or have no affect on fitness of uninfected
Should be triggered by infection

Question 7

What is illness induced anorexia?

Answer 7

Feeling sick and don’t feel like eating

Specifically associated with parasitic infection: helminths, protozoa, bacteria and viruses

Seen in both vertebrae and invertebrate

Question 8

Why does illness induced anorexia occur?

Answer 8

1. Is induced by the parasite for its own benefit
2. Starves parasites of macro and micronutrients
3. Prevents sick animals from continuing to consume contaminated food
4. Reduces the risk of pathogens moving from the gut into the blood during a systemic infection
5. Enhances immune function
6. Reduces potential conflicts between digestion related processes and immunity