Immune system & Immune cells Flashcards
(33 cards)
What is immunity?
The state of being insusceptible or resistant to a noxious agent or process, especially a pathogen or infectious disease.
How can immunity occur?
Naturally or be produced by prior exposure or immunisation.
What are the two intrinsic systems of the immune system?
- Innate (nonspecific)
- Adaptive (specific)
What is the first line of immunological defence?
Innate immune system
What is the response time of the innate immune system?
Minutes to hours
Does the innate immune system have memory?
No memory
What characterizes the adaptive immune system?
Antigen-dependant/specific and capacity for memory via memory cells
What are the two main components of the innate immune system?
- Skin
- Mucous membranes
What is the role of skin in the innate immune system?
Provides a formidable physical barrier to the entrance of microbes.
What are mucous membranes?
Mucous is slightly viscous and traps many microbes and foreign substances.
What are some antimicrobial substances in the innate immune system?
- Substances that discourage microbial growth
- Natural killer cells and phagocytes
What percentage of lymphocytes in the blood are natural killer (NK) cells?
5–10%
What are the four characteristic signs and symptoms of inflammation?
- Redness
- Pain
- Heat
- Swelling
What is fever?
An abnormally high body temperature that occurs because the hypothalamic thermostat is reset.
What commonly triggers fever?
Infection and inflammation
What effect does elevated body temperature have on the immune response?
- Intensifies effects of interferons
- Inhibits growth of some microbes
- Speeds up body reactions that aid repair
What is the role of the adaptive immune system?
Protects against infectious agents and abnormal body cells.
What are the two overlapping arms of the adaptive immune system?
- Humoral (antibody-mediated) immunity
- Cellular (cell-mediated via lymphocytes) immunity
Where do B cells and T cells develop?
In primary lymphatic organs (red bone marrow and the thymus).
What is the maturation process for B cells?
Complete their development in red bone marrow.
Where do T cells mature?
In the thymus after migrating from red bone marrow.
What is an antigen?
Substances that are recognised as foreign and provoke immune responses.
What is the first encounter between an antigen and a naive immunocompetent lymphocyte called?
Antigen challenge
What occurs during a humoral immune response?
Antibodies are produced.
