C3: Host-Parasite Relationship Flashcards
The relationship between the parasite and the host, may be divided into what following types ?
Symbiosis, Mutualism, Commensalism
When the direction moves ______ direction, means that there is a reestablishment of the host health.
When the direction moves _____ means the infection of disease happens
upward
downward
is defined as the influence of each partner by the activities of the other.
Host Parasite relationship
- The person who is infected with the parasite without any clinical or subdisease is referred to as a carrier. He can transmit the parasites to others.
Carrier State
- The disease is the clinical manifestation of the infection, which shows the active presence, and replication of the parasite causing damage to the host. It may be mild, severe and fulminant and in some cases may even cause death of the host.
Disease State
- Occurs when the host gains the upper hand; host recovers from the infection.
Parasite Destruction
In general, the host-parasite relationship can be studied under two heads:
Effects on the Parasite
Effects on the Host
What Direct Effects of Parasite on the Host?
- Parasites compete with the host for nutrients
Deprivation of nutrients, fluids & metabolites
What Direct Effects of Parasite on the Host?
- Some parasites destroy (injure) the host’s tissue when they enter the host, and others inflict tissue damage after they have successfully entered
- Parasites also infects the host by means of pressure/blockage at it grows larger
Mechanical Injury and Tissue Damage
What Direct Effects of Parasite on the Host?
- Another possible consequences of parasitism associated with cell and tissue parasites is a change in the growth pattern of the affected tissue. Some of these are serious changes, whereas others are structural and have no serious systemic importance to the whole organism.
Abnormal Growth
In abnormal growth, such changes can be broadly divided into four main types:
a. _____(Increase in the rate of cell division):
b. ____(Increase in cell size):
c. _______ (Transformation of one type of tissue into another):
d. ______ (Cancer or tumour formation):
Hyperplasia
Hypertrophy
Metaplasia
Neoplasia
What Direct Effects of Parasite on the Host?
- Specific toxins or poisons, egested, secreted or excreted by parasites have been sited in many cases as the cause of irritation and damage to hosts.
Deleterious effect of toxic substances
What Direct Effects of Parasite on the Host?
- Some ectoparasites carries other pathogens that may cause other infection.
Transmission of Pathogen to Man
What Indirect Effects of Parasite on the Host?
- Majority of the hosts build resistance or immunity against the parasite and they show no visible effects. Immunity may be natural or acquired by previous infections.
Immunologic Reaction
if a host is easily parasitized by a certain species, it is said to be _____, whereas if it is difficult to parasitize, it is called as _____
tolerant; refractory