Immune System Flashcards
Function of immune system
Protects you from infection and all sorts of pathogens and cancers
Overreaction of the immune disease examples
Autoimmune diseases
Lethal allergies
What does the immune system do
Mounts elabatote rracrions against foreign material
Antigen
A substance that the immune system reacts against
Antigens are usually pieces of a pathogen, can be other things as well
WhT tools can be used to prevent infection
Limit access to tissues
Limit access to nutrients
Unfriendly environments (temp, PH)
Directly attack pathogen
Barriers - first line of defense
Skin (constant shedding)
Mucus/respiratory tract
Sneezing, coughing
Example of mechanical barriers
Tears, mucus,
Something that flushed away pathogens
Even bleeding, it washes away pathogens trying to get into wound
Chemical defenses
Lysozyme, stomach acid, antimicrobial proteins
Second line of defense characteristics
Consists of group of cells that respond to common features of pathogens
Chemical and cellular responses that are the same regardless of specific pathogen
Fever, inflammation are system responses by this line of defense
Patterns!!
Not highly specific
What cells carry out the second line of defense
White blood cells— come from bone marrow where they are produced
They are known as leukocytes collectively
All white blood cells are leukocytes
Lymphocytes
A specific type of leukocytes that generate antibodies
Neutrophils
A type of granulocuytes (white blood cell with granules)
Most common type of white blood cell,
Engulfs and kill bacteria; mediate inflammation
Example, puss filled area, it drowns the pathogen with puss
The nucleus is multi loved
Eosinophils
Fight parasites, participate in allergic responses
They are granulosytes
Multi lobed nucleus, red orange stain
Basophils
They are blue, fight parasites (attract a basic dye) participate in allergic reactions
The nucleus is obscured under a microscope, bi-lobed
Macrophages and dendritic cells
Yes phagocytosis: process of engulfing and destroying foreign mosteriaks mostly in the tissues not blood
Phagocytes: engulf bacteria mediate inflammation, present antigens to T cells
Monocytes
This is a macrophage in a different place
Lymphocytes
T cells, B cells, and NK cells
T and B can create memory immunity
They are small cells with large nuclei
Key process in second line of defense
Phagocytosis: when cells engulf and destroy cellular waste
Neutrophils, macrophages, dendritic cells
Recognize pathogens based on shared molecular patterns called pattern recognition receptors
Chemotaxis
Phagocyte moves toward pathogens by chemotaxis
Inflammation
Influx of blood to the area
Local cells secrete chemicals (cytokines) to drive the inflammatory process
Blood vessels dilate, bringing more blood
Cytokines make area painful to the touch
What inflammation accomplishes
Gets immune cells to the area first
Activates immune cells that are there
Elicits protective behaviors in host (pain, etc)
2nd line of defense: fever
Can be induced by cytokines or pathogen associated molecules (pyrogens)
People believe fevers can be a good thing
Fever can
Inhibit multiplication of viruses and fungi
Increase reactions and production of immune cells
Impede nuttier ion of bacteria by reducing iron availability
2nd line of defense: antimicrobial protiens
Different chemicals with different tasks
Interferon protiens
Enhances immune cell growth
Secreted by cells infected by a virus
Accomplish three dif things:
Signals nearby cells to stop producing protein
If an interferon lands on a pathogen it will destroy itself
Activates white blood cells
Compliment system
Second line of defense
Stimulates phagocytes
Transferrens
Iron binding protiens
Proteins that bind iron molecules to prevent pathogens from getting to them
Complement system
Composed of a series of protein cascades
Inflammation
Formation of the membrane attack complex
Punches a hole in the cell membrane so the cytoplasm leaks leadining to the lysis and death of the invading cell
Cells involved in the third line of defense
B cells and T cells
Called into action by the phagocytes and cytokines in the second line of defense
B cells
Make antibodies
Plasma cells
Mature B cells make antibodies much more quickly
Cytotoxic T cells
Interact directly with all the cells of the body
Hyper T Cells
Work with all the components to help them work
Antigen for third line of defense
A unique recognizable movie file that a lymphocyte recognizes is called an integer
Antigen presenting cells
Use their own receptor to show off their captured and destroyed bacterial prey
T and B cell effects
These cells make antibodies which interact with the pathogens
Can be activated by interacting directly with pathogen but don’t directly fight the pathogens
MHC molecule
Individual cells hve their own MHC (class 1) If they are infected with a pathogen, foreign antigens might show up in the MHC class 1, if not, the resented peptides would all be self
Have an average cell
Produce protiens
Break those up
Put them onto MHC class 1, and expose them to outside world
If there is a virus then that’s also being presented because it’s also put onto MHC class 1 but usually it’s just broken down protien
MHC CLASS 2
Memory T and T effectors
memory B and B effectors
They live in the lymphatic tissue and Wsit there until we encounter the same pathogen
B CELLS PRODUCE antibodies
T CELLS
Interact with antigen presented by an antigen presenting cell activates a B cell
T cell reactivity
T cells are educated during fetal and infant development
The process which takes place in an organ called the thymus. This process removes T Cells that cannot recognize MHC molecules
Are specific for and will react against self protiens
Defects can lead to self reactive T cells that wage war on your own cells leads to autoimmune disease
T cells are selected based on what
Things can be foreign but not pathogenic
T cells have no way of telling the difference Like pollen (not pathogen but foreign to body so it reacts the same way as to a virus
Two different types of T cells
Cytotoxic
Helper T cells- help everyone perform better by releasing cytokines rhat help other immune cells
They activate B cells
B cell reactivity
Can interact directly with pathogen during activation
They need help from T cells
Opsimization
To make more susseptible to phagocytosis
IGG antibodies
Found in blood majority of antibodies made by plasma cells
IgM antibodies
First form created by B cells
Found in blood
IgA Antibodies
Found in mucus and breast milk, most common in whole body
Passive immunity
Babies at birth and breastfed babies recieve antibodies from mom resulting in passive immunity
Developing a strong immune system requires
Exposure to antigen/pathogens, overly sterile environments that contribute to allergies and asthma, important both to get sick to build immunity as well as to become immuno logically tolerant agents in our environment
The function of cortisol
It is a stress hormone, dampened the immune system
Reduces production of cytokines, both in age and acquired immune response is compromised, promotes apoptosis of lymphocytes
Cortisol can be used to suppress the immune system when necessary for example hydrocortisone poison ivy
