Solo disponible en BuenasTareas
  • Páginas : 3 (740 palabras )
  • Descarga(s) : 0
  • Publicado : 20 de febrero de 2012
Leer documento completo
Vista previa del texto
1.1Entry points
In spite of its barriers, pathogens still have several various entry points to the body. The principal points of entry are: wounds, the respiratory system, thedigestive system or the genitals.
1.2 The route of transmission
Each pathogen has a way of spreading from one person to another. This is known as its route of transmission. There are four main routes oftransmission.

1.3 Protection
Tissue specialized in protection:
Skin: covers the exterior of the body.
Mucous: covers the inside internal cavities that interact with the exterior (digestive,respiratory, recproductive system)
Secretions specialized in protection: saliva, gastric juices, mucus, and tears.
But sometimes foreign elements still manage to penetrate the body.
We havespecialized system that is permanently working to destroy or neutralize the intrusion : the immune system

The immune system defends us from any intrusion that might cross our protective barriers andsecretions
It is made up of organs molecules, and some very special cells: white blood cells or leukocytes
White blood cells are produced in the bone marrow. These cells are our defense against foreignelements or infectious agents.
Non-specific response:
An immediate response to any type of external attack. It only occurs where the attack is taking place.
1.8 Specific response:
It is produced whenthe non-specific response doesn’t stop the invasive agent. It is a specific attack.
Specific response bases itself on the recognition of pathogens . It recognizes a specific part of thepathogen, its antigen
An antigen is a molecule situated on the exterior of the pathogen .
Antibodies are released by white blood cells in order to detect the antigens of the pathogensAntibodies fulfill two functions:
1. Blocking pathogens and immobilizing them.
2. “Marking” the antigen for destruction by the phagocytes.
Antibiotics are substances that kill...
tracking img