Immune System Flashcards
Why do microorganisms want to infect us?
We have lots of water, proteins, nutrients, and a warm environment that they thrive in
What are some possible pathogens?
Viruses, bacteria, single-called eukaryotic parasites (yeast), parasitic worms, and maggots
What is the immune system?
A set of mechanisms that protect an organism from infection by identifying and killing pathogens
What is an autoimmune disease?
When your immune system attacks the host’s good cells
Why is it important that the immune system is adaptive?
Because pathogens are constantly evolving in order to avoid detection
What are the two types of defense mechanisms?
Innate and adaptive immunity
What is innate immunity?
A defense active immediately upon infection; includes barrier defenses; is constantly active and does not require activation, is not specific, and stops any foreign substance
What is adaptive immunity?
- Defense that is activated after the innate response and develops more slowly (because they take time to identify foreign substance)
- Is specific to certain objects and much be activated when in contact with pathogens
- Only needs to recognize something once for it to be immune for life
What makes up innate immunity?
- Recognizes traits shared by broad ranges of pathogens using a set of receptors
- is a rapid response
- Barrier defenses: skin, mucous membrane, and secretions
- Internal Defenses: phagocytes cells (phagocytosis), natural killer cells, antimicrobial proteins/peptides, and inflammatory response, and interferons
What makes up adaptive immunity?
- Recognizes traits specific to particular pathogens using a vast array of receptors
- Is a slower response
- Humoral response: antibodies defend against infections in body fluids
- Cell-mediated response: cytotoxic cells defend against infection in body cells
[ADAPTIVE] What is a humoral response?
Responses through body fluids; protects for pathogens outside of the cell
[ADAPTIVE] What is a cell-mediated response?
Controlled by t-cells which kills pathogens
Why is bone marrow so important?
It contains essential cells such as multi potent cells which branches into two different types of cells necessary for immunity
What are multipotent cells?
- Special cells in bone marrow that have stem cells (stem cells are able to keep replicating of which its progeny can differentiate into different cells)
- Gives rise to myeloid (red/white blood cells and platelets) and lymphoid (branches into 3 more lymphocyte cells)
What cells are made from myeloid cells?
-Red/white blood cells and platelets
- Granular cells: basophils, eosinophils, neutrophils, mast cells
Agranular cells: monocytes, macrophages, dendritic cells
What is made from lymphoid cells?
B lymphocytes, T lymphocytes, and natural killer cells
B AND T LYMPHOCYTES ARE THE ONLY CELLS APART OF ADAPTIVE IMMUNITY - EVERYTHING ELSE IS INNATE
[INNATE] What are the barrier defenses?
- Include skin and mucous membranes of the digestive, respiratory, urinary, and reproductive tracts
- Mucus is used to trap and allow for the removal of microbes
- Body fluids including saliva, mucus, and tears are hostile to many microbes
~ Have anti-microbial compounds that decrease the
number of pathogens (ex. Lysozymes)
~ Body fluids help to wash away pathogens, preventing colonization of microorganisms - Low pH of skin and digestive system prevents growth of many bacteria
[INNATE] What are cellular innate defenses?
- Innate immune cells in mammals detect, devour, and destroy invading pathogens
- These cells recognize groups of pathogens using TLRs or Toll-like receptors
~ Recognize fragments of molecules characteristic of a set of pathogens
~ Some are found on the surface of cells and stick out; they attack pathogens in extracellular fluid