Pathogens (Tasos - Parasites)

Question 1

What are the differences between eukaryotic and prokarotic cells?

Answer 1

Eukaryotic cells:

• Bigger
• True nucleus
• Membrane bound organelles
• Cytoskeleton
• Cell division through mitosis (instead of binary fission)

Question 2

What is ‘parasitism’?

Answer 2

• Relationship in which the parasite is dependent on the host, feeding at its expense

Question 3

Name some advantages of parasitism as a ‘lifestyle’

Answer 3

• No need to move after host location
• Food permanently available
• No complicated food capturing mechanisms
• Protection from environmental stresses
• Protection from predators and pathogens

Question 4

Name some disadvantages of parasitism as a ‘lifestyle’

Answer 4

• Extreme host specificity can increase vulnerability to extinction
• Must locate to optimum site in host to ensure food
• Overcoming host immune defenses
• Transmission is risky and dangerous

Question 5

Name some factors that contribute to problems of parasitic diseases

Answer 5

• Poverty
• Lack of sanitation
• Poor nutrition
• Movement of infected people
• Natural disasters
• Lack of effective drugs
• Parasite resistance
• Lack of health infrastructure
  And many more

Question 6

Name some host factors and parasite factors that influence pathogenesis

Answer 6

Host factors:

• Genetics
• Age
• Gender
• Underlying health
• Immune status
• Presence of co infections

Parasite factors:

• Genetics
• Growth rate
• Reproduction
• Virulence factors

Question 7

Name some direct and indirect mechanisms by which parasites cause disease

Answer 7

Direct:

• Consumption of host tissue
• Competition for nutrients
• Production of toxins etc
• Physical destruction of host tissue

Indirect:

• Overstimulation of the immune system
• Stimulating auto-immunity
• Compromising immune system
• Alteration of gut microbiota
• Altering homeostasis
• Increasing susceptibility to other diseases

Question 8

Name some types of parasitic pathologies

Answer 8

- Abortion pathology
> Toxoplasma
- Anemia
- Anorexia 
- Apoptosis
- Calcification
- Cancer
> Tania solium
- Dilusional parasitosis
- Diarrhea
> Cryptosporidium
- Elephantiasis
- Fever
- Hyperplasia
- Hypertrophy
- Jaundice
- Damage to specific organs
> Bladder
> Brain
> Kidney
> Lungs
etc

Question 9

Names some mechanisms of parasite transmission

Answer 9

• Contaminative transmission
• Transmission associated with reproduction
• Autoinfection (life cycle in one organism)
• Hospital-acquired infection
• Active parasite transmission
• Can be influenced by religion, war and environmental factors