B2 W1 - Innate Immunity Flashcards
What is the primary function of the immune system?
The immune system protects against infectious diseases.
What is an antigen?
An antigen is any molecule that can trigger an immune response in both the innate and adaptive immune systems.
Which branch of the immune system provides the first line of defence?
The innate immune system is the primary line of defence, offering a more immediate response.
How quickly does the innate immune system respond to a threat?
- Rapid response
- Typically within hours or a few days.
How long does it take for the adaptive immune response to develop?
Usually several days to weeks.
What types of threats does the innate immune system recognise?
General molecular patterns commonly found in pathogens, but absent in humans.
How does the adaptive immune system’s recognition abilities differ from the innate system?
The adaptive immune system can potentially recognise a vast array of threats, including specific antigens.
Does the innate immune system exhibit memory of past infections?
- No
- The innate immune system lacks memory.
Why does the adaptive immune system have memory?
- Clonal selection
- A process where cells that recognise a specific threat are expanded and some are retained as memory cells.
What is the consequence of the adaptive immune system’s memory?
Immunological memory allows the adaptive immune system to mount a faster and stronger response upon re-exposure to the same threat.
What characterises the innate immune system’s specificity compared to the adaptive immune system?
The innate immune system is non-specific, while the adaptive immune system is highly specific.
How is innate immunity described in terms of its presence and induction?
Innate immunity consists of natural defences that are present at birth and do not require prior exposure to a pathogen to become active.
How long does a typical innate immune response last?
The innate immune response is relatively short-lived.
What is a potential drawback of the innate immune system’s regulation and amplification?
The innate immune system’s response has relatively poor amplification and regulation, which may pose a risk of damaging self-antigens.
From an evolutionary perspective, how is innate immunity viewed?
Innate immunity is the more ancient form of immunity, found widely across various species.
What are the three main components of the innate immune system?
The three main components of innate immunity are:Physical barriersWhite blood cells (leukocytes)Humoral elements (plasma proteins)
What is the fundamental principle of barrier immunity?
Barrier immunity aims to prevent microorganisms from entering the body, or more specifically, from penetrating beyond body cavities and luminal spaces.
What is the body’s primary physical barrier against infection?
Skin acts as the primary physical barrier, effectively preventing most infectious agents from entering the body.
Besides the skin, what other physical barriers contribute to innate immunity?
Mucous membranes and the mucus they secrete, along with cilia in the respiratory system, also play a crucial role as physical barriers.
What are some examples of ‘biochemical barriers’ in innate immunity?
Biochemical barriers include skin secretions, enzymes like lysozyme in tears, stomach acidity, and the presence of commensal organisms.
How do commensal organisms contribute to barrier immunity?
The body’s normal microbiome, or commensal organisms, protect against harmful organisms, primarily by competing for resources.
Where do most infectious agents typically enter the body?
Most infectious agents enter the body through mucosal surfaces like the nasopharynx, respiratory, gastrointestinal, and genitourinary tracts.
What is the function of mucus on interior epithelial surfaces?
Mucus, containing secreted mucins, prevents pathogens from adhering to epithelial surfaces and aids in their clearance by cilia.
What are defensins, and what is their role in barrier immunity?
Defensins are peptides found in mucus, such as in the GI tract, that kill or inhibit the growth of pathogens.