Immunology Flashcards
What are the physical non-specific defences in the human body?
- Skin: physical barrier, preventing the entry of pathogens into the body
- Mucosa: found in various mucous membranes, serves as a protective barrier that helps trap and eliminate pathogens.
- Respiratory cilia: hair-like structures in the respiratory tract that move in coordinated waves, helping to trap and remove foreign particles, including pathogens.
- Flow of fluid in various bodily systems: such as blood and lymph, helps transport immune cells and antibodies throughout the body, enhancing the overall non-specific defence mechanism
*stomach acid very icididc can kill bugs
*saliva has enzymes which can be protective, the flow of saliva prevents bugs from getting into salivary galnds
*skin and mucosa repair rapidly
what is acute ascending parititis?
elderly
dehydrated and run down
reduced salivary flow in which bugs from mouth can move to parotid
how can our UT be infected ?
sometimes ascending infections
What is inflammation?
Inflammation is a rapid non-specific defense mechanism characterised by the body’s response to injury, infection, or irritation.
how does inflammation contribute to non-specific defenses?
involves the activation of immune cells, blood vessels, and molecular mediators to eliminate the cause of cell injury, clear out damaged cells and tissues, and initiate tissue repair.
list the stages of the inflammation process
- trigger
- vasodilation and increased permeability
- chemotaxis
- phagocytosis
- releases of mediators
explain the trigger part of the inflammation process
Inflammation is triggered by various stimuli, such as infection, tissue injury, or exposure to harmful substances.
explain the vasodilation and increased permeability process of inflammation
Blood vessels in the affected area undergo vasodilation, leading to increased blood flow. This is accompanied by increased permeability of blood vessel walls, allowing proteins and cells to move from the bloodstream to the affected tissue.
explain the chemotaxis part of the inflammation process
White blood cells (leukocytes), particularly neutrophils and macrophages, are attracted to the site of inflammation through a process called chemotaxis. cytokines are released at the site of injury or infection guide these immune cells to the affected area.
explain the phagocytosis part of the inflammation process
White blood cells (phagocytes) engulf and digest foreign particles, such as bacteria or damaged cells, through a process called phagocytosis. This helps to eliminate the source of inflammation.
explain the release of mediators part of the inflammation process
Inflammation involves the release of various chemical mediators, including cytokines, histamines, and prostaglandins. These mediators play a crucial role in coordinating the inflammatory response, including vasodilation, increased permeability, and the recruitment of immune cells.
list some properties of WBC
- antimicrobial properties - WBC release reactive substances (peroxide and oxygen radicals )which react with toxins and pathogens causing them to denature
- antigen presentation - to allow immune system recognition *similar in specific defences
- antigen/ antibody uptake
- wound healing
- phagocytosis
- bone resorption
list the 5 signs of inflammation
- CALOR - heat
- RUBOR - redness
- TUMOR - swelling
- DOLOR - pain
- FUNCTIO LAESI - loss of function
what bridges the gap between non specific and specific defences?
complement cascade - this provides a rapid non specific response to triggers
what are the 3 pathways in the complement cascade ?
classical
lectin
alternative
what is the characteristic feature of the Complement Cascade?
it Increases in size as it continues to be activated, even by the smallest triggers, showcasing its amplification in response.
What is the dependency for stimulation in the classical pathway of the Complement Cascade?
activation of C1
What are some stimuli that can activate the Complement Cascade?
- Inflammation
- Bacteria, Viruses, Fungi
- Tissue Damage
- Antibodies
What is the effect of the complement pathway known as opsonization?
the process by which the complement pathway tags a pathogen or infected cell, making it more susceptible to phagocytosis
- What is the outcome of the complement pathway related to cell lysis?
destruction of pathogens or infected cells
What is one of the effects of the complement pathway in the context of the immune response?
induction of inflammation, contributing to the overall immune response.
What is Hereditary Angioedema?
an inherited deficiency of C1 esterase inhibitor, leading to uncontrolled activation of the complement cascade through the classical pathway and resulting in excess swelling, particularly in areas such as the lip, tongue, and airways
head and neck swelling
What triggers the excessive swelling in Hereditary Angioedema?
can be triggered by trivial trauma or may occur spontaneously
how do we manage hereditary angidema ?
C1 esterase inhibtor drug
and regulate complement cascade
What is meant by Specific Immunity?
the body’s ability to mount a targeted and precise immune response against specific pathogens or substances, providing a tailored defense mechanism.
What characterizes Antigen-Specific Immunity?
the immune system’s ability to recognize and respond to specific antigens, which are typically proteins, peptides, or complex molecules.
What are Antigens, and what forms can they take?
substances that can induce an immune response. They can take the form of proteins, peptides, or complex molecules, serving as triggers for the immune system
what are antibodies? what is their role in immunity?
Antibodies, also known as immunoglobulins, are proteins produced by the immune system in response to specific antigens. They play a crucial role in recognizing and neutralizing pathogens
How does the interaction between Antibodies and Antigens work?
Antibodies have complementary regions that “fit” onto specific antigens, creating a lock-and-key mechanism. This interaction allows antibodies to bind to antigens with high specificity.
besides binding to antigens, what other functions can the effector end of Antibodies perform?
the effector end of antibodies can bind to complement proteins, immune cells, and other molecules, mediating various immune responses such as complement activation and immune cell recruitment.
What is the primary source of antibody production in the immune system?
b cells
How do antigens interact with B cells to initiate antibody production?
Antigens, whether circulating in the blood or present on mucosa surfaces, can come into contact with B cells. The B cell receptor recognizes the antigen, initiating the production of antibodies by the B cell
What is the process by which B cells multiply and produce more antibodies when stimulated by an antigen?
clonal expansion
Besides producing antibodies, what additional role can the multiplied B cells play?
The multiplied B cells can also differentiate into memory cells. These memory cells store information about the encountered antigen, leading to a quicker and more efficient immune response upon subsequent exposures.
What is the primary mechanism of Humoral Immunity?
it works through the production of antibodies in response to the presence of antigens.
very effective against bacterial and viral antigens
In lymph nodes
what is cell mediated immunity?
requires direct engagement of cells with the target to initiate the immune response, in contrast to B cells producing antibodies
Cell-Mediated Immunity is effective against tumor cells, virus-infected cells, and non-self cells
What is depicted in the image regarding Adaptive Immune Memory?
The image illustrates the concept of clonal expansion in Adaptive Immune Memory, showcasing an exaggerated response upon the second exposure to a pathogen.
What occurs upon exposure to an antigen in the context of Immunological Memory?
Exposure to an antigen triggers both Humoral and Cell-Mediated responses in the immune system
- What is the significance of clonal expansion of antigen-specific lymphocytes in Immunological Memory?
Clonal expansion leads to the persistence of antigen-specific lymphocytes in lymph nodes, contributing to a faster and more robust immune response upon second or third exposure to the same antigen.
What is the primary goal of immunisation?
to capitalize on immunological memory, enabling the host to mount an effective immune response if exposed to antigens in the future.
What is the causative agent of Tetanus?
Clostridium tetani.
common in developing countries
in soil
What is the primary effect of the toxin produced by Clostridium tetani?
The toxin produced by Clostridium tetani travels to the central nervous system (CNS) and causes uncontrolled muscle spasms. can lead to respiratory failure and can be fatal
locked jaw too
Tetnus - Treatment Options
- How does passive immunity work when considered as a treatment option?
- Immunoglobulin: antibodies against tetanus toxin.
-Passive immunity = No “engagement” of immune system - Antibodies infused into patient
No lasting immunity
No lasting protection
tents - tx options -How does tetanus toxin work when considered as a treatment option?
- Give the pt the toxin instead of the antibodies
- Would engage immune system
- This is active immunity
- But toxin is dangerous
- can give modifies version
- Same antigencity as toxin
- No toxic effect
- Engages Immune System
- Active Immunity
- Lasting protection
Tetnus - Treatment Options
- How does immunisation work?
- Toxins/toxiods: aim to neutralise effect
- Virus/bacteria
- Dead
- Live attenuated
- Viral Particles
- DNA/RNA
Define autoimmune disease?
condition in which the immune system, which is designed to protect the body from harmful pathogens, mistakenly attacks its own cells, tissues, or organs
Examples of bone and tissue autoimmune disease?
RA
lupus
Examples of Endocrine autoimmune diseases?
- Type 1 DM
- Addison’s
- Autoimmune thyroiditis - more or less thyroxine
Examples of autoimmune GI tract diseases?
- Coeliac
- Pernicious anaemia - attacks stomach and small bowel causing malabsorption of vit b
examples of autoimmune PNS/CNS examples?
- Multiple Sclerosis
- Myasthenia Gravis - affects neuromuscular junction can cause weakness can’t move muscles
examples of autoimmune skin/mucose diseases
- Pemphigus
- Pemphigoid
- eczema
- scleroderma
eg of autoimmune Saliva/Tear Gland diseases
Sjogren’s syndrome
examples of autoimmune heart conditions
rheumatic fever - strep infection
What role does the Major Histocompatibility Complex (MHC) play?
- Involved in cell-cell interactions
- Allows immune system to tell self from non-self
- Non-self cells are treated as foreign and attacked.
Why is compatibility between donor and recipient blood types crucial in blood transfusions?
Compatibility ensures that the recipient’s immune system does not react adversely to the transfused blood, preventing complications
What is the purpose of cross-matching in blood transfusions?
Cross-matching checks for compatibility by mixing samples of the recipient’s and donor’s blood to detect potential adverse reactions.
How does MHC matching impact organ transplantation?
The closer the match between donor and recipient MHC molecules, the lower the risk of rejection in organ transplantation.
What is the role of immunosuppressive medications in organ transplantation?
Immunosuppressive medications are used to prevent rejection by suppressing the recipient’s immune response against the transplanted organ.
Why does organ rejection occur when the MHC of transplanted tissue is different from the recipient?
Organ rejection occurs because the recipient’s immune system recognizes the transplanted tissue as foreign due to differences in the Major Histocompatibility Complex (MHC)
What is the term for the immune response that leads to organ rejection?
“host vs graft disease.”
What is the primary purpose of stem cell transplant?
repopulate the patient’s bone marrow and blood with immunocompetent stem cells
n the context of leukaemia, what type of cancer is it?
blood cancer
How is the preparation for a stem cell transplant typically done in terms of existing blood cells?
Chemotherapy and radiotherapy are used to kill all blood cells, including haematopoietic stem cells, as part of the preparation for a stem cell transplant.
Blood Transfusion and Transplant - Dental
- Can you see host vs graft disease?
yes in mouth
patches
What happens when grafted cells in a stem cell transplant recognise the patient’s tissues as foreign?
Grafted cells may attack the patient’s tissues, recognizing them as foreign, particularly based on the Major Histocompatibility Complex (MHC)
In graft vs host disease, which tissues are commonly affected?
Graft vs host disease can affect various tissues, including the skin, gastrointestinal tract (GIT), liver, and oral tissues
might need to give them saliva if they have dry mouth or fluoride toothpaste
how would we manage autoimmune diseases and rejections
steroids
methoteraxte
biological response modifiers
What are some common iatrogenic causes of immunodeficiency?
autoimmune and inflammatory diseases, chemotherapy, and patients who have undergone transplantation
Name some conditions, often related to blood disorders, that can lead to immunodeficiency.
lymphoma, leukemia, and myeloma are associated with immunodeficiency
in what cases might immunodeficiency be inherited?
Immunodeficiency can be inherited, meaning it is passed down genetically, leading to deficiencies in the immune system.
