Immune System Flashcards
What is a pathogen?
A disease-causing organism, such as a virus, bacteria, protozoa, or fungus
The scientific study of pathogens is called Pathology.
What are the characteristics of bacteria?
Prokaryotes, divide by binary fission, can cause diseases such as:
* Food poisoning (e.g. Salmonella)
* Ear and eye infections
* Strep throat
* Cholera
* Diarrhea
What is a virus?
Acellular, requires a host cell for life functions, can have DNA or RNA, cannot be killed by antibiotics, mutates quickly
Causes diseases such as flu, HIV, smallpox, measles, common cold, herpes, and ebola.
What are fungi?
Eukaryotes that reproduce with spores, cell walls contain chitin, can cause:
* Athlete’s foot
* Mould
* Ringworm
* Vaginal candidiasis
* Allergic reactions and respiratory problems
What is protozoa?
Unicellular eukaryotes that can be parasitic or symbiotic, causing diseases like:
* Malaria
* Leishmaniasis
* Toxoplasmosis
* Giardia
* Lyme’s disease
What are helminthic parasites?
Multicellular eukaryotic parasites that can cause:
* Elephantiasis
* Schistosomiasis
* Toxocariasis
* Pinworm
* Roundworm or tapeworm infections
How can pathogens be transmitted?
Through:
* Inhaled droplets
* Direct contact
* Bodily fluids
* Animal vectors
* Blood contact
* Ingestion
What is innate immunity?
Nonspecific defense mechanisms that come into play immediately or within hours of an antigen’s appearance
Includes physical barriers and macrophages attacking pathogens.
What is adaptive immunity?
Specific defense mechanisms using antibodies
Includes active immunity (produced by the organism) and passive immunity (acquired from another organism).
What are the two layers of skin?
The dermis (underneath layer) and the epidermis (outer layer)
The epidermis mainly consists of dead cells that provide a barrier against pathogens.
What role does stomach acid play in pathogen defense?
Kills pathogens that enter the body through food and water due to its acidic environment.
What is the process of blood clotting?
Involves:
* Platelets and damaged tissue release clotting factors
* Conversion of prothrombin into thrombin
* Thrombin catalyzes conversion of fibrinogen into fibrin
What are the two types of lymphocytes?
B cells and T cells
B cells produce antibodies, while T cells mediate B cell activity and destroy virus-infected cells.
What is phagocytosis?
The process by which macrophages engulf and digest invading pathogens.
What is a primary immune response?
The initial response to a novel pathogen, involving non-specific immune response and antibody production.
What triggers antibody production?
Antigens, which are substances or molecules found on cell or virus surfaces.
What is clonal selection?
The process by which activated B cells divide to produce clones of plasma cells that secrete the same antibody type.
How do memory B-cells function?
Remain inactive until the same pathogen infects the body again, allowing for a rapid immune response.
What is humoral immunity?
The pathway by which antibodies are produced by B lymphocytes to target exogenous antigens.
What is cell-mediated immunity?
Targets endogenous antigens, involving cytotoxic T cells that bind to and kill infected or cancerous cells.
What is antigen presentation?
The process where a macrophage engulfs a pathogen and presents its antigen to a Helper T-cell via MHC proteins.
What are plasma cells?
Mature B lymphocytes that secrete a large number of antibodies during an immune response.
Plasma cells are crucial for the adaptive immune response, producing antibodies that target specific pathogens.
What is the primary immune response?
The initial response to a novel pathogen, involving non-specific immune response and antibody creation.
Symptoms of disease typically develop during this response due to the time it takes for the body to produce antibodies.
What is the secondary immune response?
The response to a second or subsequent exposure to a pathogen, characterized by rapid antibody production from memory B cells.
This response is usually faster and produces more antibodies than the primary response.
What is HIV?
Human Immunodeficiency Virus that gradually attacks the immune system, making it harder to fight infections.
HIV infection can lead to AIDS if not treated effectively.
What is AIDS?
Acquired Immune Deficiency Syndrome, a condition caused by HIV where the immune system is too weak to fight off infections.
Individuals with AIDS are susceptible to opportunistic infections due to weakened immunity.
How is HIV transmitted?
Through the exchange of body fluids, including unprotected sex, blood transfusions, and breastfeeding.
Using latex protection can minimize the risk of transmission.
What cells does HIV specifically target?
T-helper cells (CD4+ macrophages).
These cells are crucial for coordinating the immune response.
What are attachment inhibitors?
Drugs that prevent HIV from connecting to the CD4 receptor, blocking its ability to inject genetic information.
They are part of the treatment strategy for HIV.
What is a zoonosis?
A disease that can be transmitted from animals to humans.
Examples include measles, syphilis, and Lyme disease.
What is vaccination?
A method that allows an individual to become immune to a disease without experiencing it.
Vaccination triggers a primary immune response, producing memory cells for future protection.
What is herd immunity?
When a large portion of a population becomes immune to a pathogen, protecting non-immune individuals.
It is essential for controlling the spread of infectious diseases.
What are antibiotics?
Drugs used to treat and prevent prokaryotic bacterial infections by disrupting bacterial processes.
Antibiotics are ineffective against viruses.
What leads to antibiotic resistance in bacteria?
Indiscriminate use of antibiotics, allowing resistant strains to proliferate.
Resistance can occur through natural selection as bacteria mutate.
What are integrase inhibitors?
Drugs that prevent the integration of viral DNA into the host’s genome.
They are part of the treatment regimen for HIV.
What is the role of helper T cells in the immune system?
They communicate with B lymphocytes to initiate antibody production.
Without helper T cells, the immune response is severely impaired.
What is the significance of memory cells?
They enable a faster and stronger secondary immune response upon re-exposure to a pathogen.
Memory cells are essential for long-term immunity.
What are some examples of opportunistic infections associated with AIDS?
- Tuberculosis
- Salmonella
- Pneumonia
These infections are more severe in individuals with weakened immune systems.
What is the consequence of HIV destroying helper T cells?
The immune system cannot communicate effectively, leading to reduced antibody production.
This leaves the body vulnerable to infections.
What is the impact of inadequate medical care on HIV infection rates?
It can lead to increased infection rates due to lack of education and resources.
Addressing healthcare disparities is crucial for controlling the epidemic.
What are the steps to blood clotting?
- When a small blood vessel is damaged, cells release chemicals that cause platelets to
adhere to the damaged area. - The damaged tissue and the platelets then release chemicals called cloning factors to
convert prothrombin (inactive protein) into thrombin (active enzyme). - Thrombin is an enzyme that catalyzes the conversion of fibrinogen into fibrin
- Fibrin is a fibrous protein which forms a
mesh-like network that helps to form a clot - Cellular debris gets trapped in fibrin mesh
and helps to form a stable clot
