Immune System Flashcards
Why is the internal environment of an animal favorable to a pathogen?
Full of nutrients, protected from outside sources, acts as a means of transportation, and is climate-controlled.
What are the four ways pathogens enter the body?
- The skin
- The digestive system
- The respiratory system
- The urogenital tract
What is a pathogen?
An organism or virus that causes disease.
What are the three approaches to fighting pathogens?
- Physical barriers
- Immunological barriers
- Branches of the immune system
What do immunological barriers accomplish?
They recognize the foreign invader by differentiating it from self (molecular recognition) and employ mechanisms to destroy the foreign invader.
What are the two branches of the immune system?
Innate and adaptive immunity.
How does the broad recognition of innate immunity work?
Occurring in all animals, innate immunity molecularly recognizes pathogens using a small set of receptors that bind to molecules or structures that are absent from animals but are common in a group of viruses, bacteria, or other microbes.
How does the speed of innate vs adaptive immunity compare?
Innate immunity has a rapid response while adaptive immunity is slower.
How does the specific recognition of adaptive immunity work?
This system molecularly recognizes pathogens using a vast arsenal of receptors, each of which recognizes a feature typically found only on a particular part of a particular molecule of a particular pathogen.
How does the specific killing of adaptive immunity work?
Defenses elicited are against a specific pathogen or closely related pathogens, and these specific mechanisms also activate the innate arm of the immune system.
What does it mean to say the adaptive immunity system has memory?
Adaptive immunity is enhanced by prior exposure to the infecting pathogen.
What is the main goal of the immune system?
To keep you from getting sick–not to keep you from getting infected.
What is the physical barrier of the innate immunity of insects?
The exoskeleton.
How does the innate immunity of insects perform recognition?
Pattern recognition receptors recognize macromolecules that are characteristic of a broad class of pathogens.
What do hemocytes of the insect immune system do?
They broadly respond to invaders.
Which signaling pathways broadly respond to pathogens in the insect immune system?
Toll, Imd, and Jak/Stat pathways.
What is the Toll pathway especially effective against?
Gram-positive bacteria.
What is the Imd pathway especially effective against?
Gram-negative bacteria.
What are the effector mechanisms of the insect innate immunity system?
Phagocytosis, lytic antimicrobial peptides, and others.
What is phagocytosis?
An evolutionarily conserved immune response. It is a type of endocytosis in which large particulates or small organisms are taken up by a cell.
What are the phagocytic cells of arthropods?
Hemocytes.
What are the phagocytic cells of mammals?
Mainly macrophages, neutrophils, and dendritic cells.
List the six steps of phagocytosis.
- Pseudopodia surround pathogens.
- Pathogens are engulfed by endocytosis.
- Vacuole forms.
- Vacuole and lysosome fuse.
- Pathogens destroyed.
- Debris from pathogens released.
What is the barrier defense of innate immunity in vertebrate animals?
The skin and the mucous membranes that line the digestive, respiratory, urinary, and reproductive tracts.