Lesson4 - Immune System Flashcards
what is the function of the immune system?
target and destroy the pathogens that invade the animal’s body
what are pathogens?
microbes and viruses that cause disease
what is the microbiota?
beneficial bacteria, non-pathogenic or commensal microbes
the immune system of animals can be split into 2 things, which are?
- innate immunity
- adaptive immunity
what is innate immunity?
A defense system that operates in all animals. ex: barrier defenses, cells specialized in the rapid recognition of pathogens, and chemical defenses
adaptive immunity is a defense system exclusive to…?
vertebrates
which cells are specialized cells of the adaptive immune system?
B cells and T cells called lymphocytes
what is the function of lymphocytes?
target specific pathogens by recognizing specific parts of specific molecules of specific pathogens
in insects, what is the innate immunity barrier?
chitin exoskeleton - a barrier defense that protects against intruding microorganisms
what happens once the first line of defense is breached in insects?
specialized cells circulating in the hemolymph seek and destroy invading pathogens
what are hemocytes?
-the phagocytic cells that recognize pathogens from molecules on their cell surface.
-once engulfed by a hemocyte, the pathogen is confined to a vacuole that fuses with a lysosome containing enzymes that destroy it.
-digested pathogen is exported out of the phagocytic cell via exocytosis.
what are the functions of hemocytes circulating in the hemolymph? (2)
- secrete short-chain amino acids called antimicrobial peptides
- recognize and engulf pathogens
what can antimicrobial peptides do?
can perforate the plasma membrane of pathogens and instantly cause them to lyse
what do bacteria lack? what does that have to do with pathogens?
- a cytoskeleton
- puncturing plama= contents of the cell spill out
where do lymphatic vessels equipped with one-way valves, that move fluid unidirectionally, move the fluid towards by bulk flow?
a vast network of lymph nodes
where does the interstitial fluid collected from the top right half of the body drains into?
the right subclavian vein
where does the interstitial fluid collected from the left and bottom half of the body drain into?
left subclavian vein
what are the primary tissues of the immune system?
bone marrow and the thymus, where the cells of the adaptive immune system develop and mature
what are the secondary tissues of the immune system?
- adenoid gland
- tonsils
- spleen
- peyer’s patch
- appendix
- large intestine
what does the barrier defense include in mammals?
1.skin
2. secretion from glands
3. mucous membranes of the digestive, respiratory, and urogenital tracts
what prevents the growth of pathogenic microbes?
- commensal bacteria
- skin
- lining of urogenital tracts