Intro to immunity Flashcards
What is a pathogen?
Pathogens are causative agents of disease
What are pathogens classified into
Cellular and Non cellular
Give me a list of each cellluar and non cellular pathogens
Cellular
1. Bacteria
2. Protists
3. Fungi
4. Parasites
Non cellular
1. Viruses
2. Prions
Bacteria. explain about it a little
It is prokarytoic,
Unicellular THAT has NO nucleus but has DNA and no membrane bound organelles
Reproduces via binary fission and so can rapidly develop infection
How do bactria cause diseqse
They release toxins and enzymes which disrupt functioning of cells
Viruses aim and about them
They are not living
Viruses are composed of genetic material (DNA or RNA) encased in a protien coat. (Capsid)
They aim to cause diseases through the lysis of cells when infecting and replicating.
They reproduce by injecting genetic material into a host cells and using the cell to replicate continously.
What is it called when a virus is inside and outside a host cell
Inside: Virus
Outside:Virion
Does the virus infect any cells?
No, it recognises specific receptors on cell membrane
Fungi
They are unicelluar OR multicelluar
Eukaryotic organisms that contain long branch filaments Hyhae
They reproduce via forming spores
And they infect similarly to bacteria
Are fungis more common in aniamals or plants
Plants
What are protists
They are unicelluar eukarytoic organism
They live in the host and reproduce 2 ways ( binary and budding)
eg malaria
What 2 ways do protists reproduce:
Binary fission nd budding
What is a prion
An incorrectly folded protiens in the brain that can cause other normal protiens to unfold as well
Do prions contain genetic material
No, its just a protien, so nucleic acids
How do prions reproduce
By inducing other properly folded protiens to convert them into the diease causing prion form
What are parasites
They are eulkarytoic organisms and can live on or in a host
What are hte most common parasite and how to they reproduce
Worms, sexually ( egg larval) or asexually ( breaking off segments )
what are antigens?
Molecules or parts of a molecule that may trigger an specific immune response
How will the immune systwem interact or recoginse a molecule
By cellular signalling
What is a disease
Disease refers to imparied functioning of cells or processes in the body.
What different types of antigens can exists
RNA DNA Protiens sugrs
Antigens are found on the surface of a pathogen?
Not always, they can be free floating
What are the two types of antigens that the immune system uses tro recognise if its one of the gang or nah
Self antigens and non self antigens
What are self antigens
They are antigens that are present on the surface of ALL self cells which allow the immune syustem to distinguish its self from non self antigens
What are the MOST IMPORTANT self antigens
MHC protiens
What are non self antigens
Non self antigens are from outside the body that is recognised as foreign material and initates a immune response
What are MHC protiens
They are protiens found on the surface of cells which display antigens to other cells in the body to show whether the cell is healthy or not healthy.
What are the two types of MHC protiens and explain
MHC class 1- They are found on all nucleated cells in the body ( it presents a little part of what the cell is making on the mhc clas 1, like its saying hey this is whars happening inside me)
MHC class 2- Only found on specialised immune cells ( note they will have both mhc 1 and 2)
This isnt completely true for eveything but for VCAA what are the cells that display MHC 2 markers
Macrophages, dentritic cells, and B lymphocytes
Do MHC 1 markers differ between individuals?
YUP
What happens if the immune system cant drecoginse the antigen markers
It is therefore a non self antigen and then attacked
WHat is called when self antigens are recognised incorrectlty as an non self
An autoimmune disease
What is an autoimmune response
WHen immune response is produced against its own cells due to recgognising self cells as non self.
But why tf does immune system mistake my self antigens
Autoimmune disorders may be triggered by infection , this is as the shape for a non self antigen from a pathogen could be similar in shape compared to a self antigen
What happens when recognising non pathogenic **NON ** self antigens as pathogenic?
An allergic response.
What is an allergic response
A specific type of immune respinse where the immune system overeacts to the antigen
So blood cells dont have mhc markers so then what?
All blood cells instead have a H antigen and varying types of antigens on their red blood cell surface
What are the differentt types of blood group is there and what type of antibody does it produce
Type A- red cell with a A antigen - produces ANTIbody B
Type B- red cell with a B antigen- produces ANTIbody A
Type AB-Red cell with A and B- doesnt produce any antibodies
Type O-Red cell wiht NO antigens- produces BOTH Antibody A and b
What is the aim of the immune system?
To prevent diseases and stop the disease from being progessively worse.
What are types of Immune syem and the lines of defence it dalls under
Innate system- First and second line of defence
Adaptive system- Third line of defence
What is the first lline of defense
And the three types
It is mechanisms used to prevent pathogens from entering the organism
Physical, chemical and microbiological
What is physical barriers
Solid or fluid that prevents the pathogen from entering animals / plants
What are examples of physical barreirs in animals and plants
Animals- Intact skin
Mucus secretion and cilia
Plants- Closing of stomata
Waxy cuticles
Formation of galls
Thorns/ trichomes
Why does intact skin prevent infection?
The outer layer of skin cells are layers of dead cells, therefore viruses on the skin can infect dead cells.
Explain mucus scretion ands cilia
The lining of the airway secrete mucus which trap the bacteria, the lining of the airway have cilia on the surface which vibrate and push the pathogens into our throat to be vomited/coughed out or to be destroyed by stomach acid
What is cehmical barriers
Toxins and enzymes produced that inhibit growth or destroy pathoens
What are some chemical barriers in animals and plants
Animals
1.Enzymes that digest the protiens in bacterial walls found in sweat,tears,saliva
2.Stomach acid (low ph, strong acid kills many pathogens)
3.Antibacterial protiens in semen
Plants-
1.Produce chemicals which is toxic if ingested
What is microbiota barriers
THe presence of normal flora that prevents the growth or spread of microorganisms that may be pathogenic by producing chemicals or due to competiton.
What is the second line of defense?
A non specific response that involves various cells and molecules that destroy pathogens rapidly
What pathogens have a cell wall
Bacteria and Fungi
