Learning about Immunology

Learning about Immunology.

Immunity as a word was derived from a Latin word “immunis” which means exempt.

The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism’s own healthy tissue. (Wikipedia).

The immune system is divided into two:

  1. Innate or Static
  2. Responsive or Adaptive

The Innate or Static immunity is a system whcih forms the first line of defense against an attack to the system. It doesn’t change with repeated exposure and the resistance is static. Examples include skin and epithelial surfaces.

The adaptive system which is the second line of defense on the other hand is activated the moment the innate or static system becomes overwhelmed. They are specific to the infective agent and are capable of storing the information about the invader as memory which helps it to have an enhanced response to other subsequent challenge.

Immunology is the branch of biomedical sciences that is concerned with every aspects of the immune system in all multi cellular organisms.

Ways in which immune system contribute to diseases include

  1. Activation
  2. Immunodeficiency
  3. Hypersensitivity


The immune system becomes active when it mounts an immune response and when fighting an infection. This can result in fever, or an inflammation and then the removal of pathogen. The immune system also keep in memory information about the pathogen so it can fight it better the next time it attacks.


When a component of the immune system is missing or when factors such as drugs, disease e.g. HIV stops it from working properly, the immune system stops working properly and will be unable to fight against infections.


The immune system can become Hypersensitive against the normal body (autoimmunity) or against substance that are harmless (allergy). On the other hand the immune system can become hypersensitive leading to Allergies.

See post on World Malaria Day



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