Immune System Flashcards
antibodies deal with antigens by:
- combine with bacterial/viral toxins/enzymes that inhibit them
- bind to viruses to prevent cell entry
- coat bacteria for easy phagocytosis
- cause agglutination of foreign particles
- make substances insoluble to phagocytose
passive immunity
immunity produced by the introduction of antibodies from another person. (breast milk,natural) or (tetanus shot, artificial)
do not undergo an immune response
active immunity
immunity produced by the body.
manufacturing antibodies against a foreign antigen.
contracted disease and undergoing an immune response
(chicken pox, natural) (vaccinated, artificial)
natural immunity
occurs without human interaction.
no injections
artificial immunity
giving people an antigen or antibody (human intervention)
needles
attenuated
micro-organisms that have been reduced in virulence so the body has the ability to reduce disease symptoms
pathogen
disease causing organism
non-specific defences
work against all pathogens
fever, inflammatory response, phagocytosis
specific defences
provide protection against a specific micro-organism
B and T cells
Humoral response, cell mediated response
antibodies
Protein substance which circulate around the body and attack invading agents
B Cell
involved in Humoral response
produced in bone marrow and matured in bone marrow
develop into plasma cells which secrete antibodies and also into memory cells
T Cell
involved in cell mediated response
produced in bone marrow and matured in thymus
develop into Killer T cells, Helper T cells, Suppressor T cells and Memory T cells
Killer T Cell
migrate to a place where large numbers of antigens are present. Attach to antigen and destroy it
Helper T Cell
secrete substances that 1. sensitises more lymphocytes 2. attract more macrophages 3. enhance macrophage activity
Suppressor T Cell
release substances that inhibit B and T cells after infection is over
Memory T Cell
respond to antigen previously exposed to the body faster and antibodies in larger quantities.
stored in lymphoid tissues around the body
Antigen
Any substance capable of causing a specific immune response
Plasma Cell
secrete specific antibodies capable of attaching to the active site of an antigen
Inflammatory Response
- damage occurs, mast cells release histamine and heparin that attract phagocytes into intercellular fluid
- histamine increases blood flow and increase capillary permeability
- heat, redness and swelling
- heparin prevents clotting to allow WBC to get to the area
- phagocytes move in to clear debris
- pain receptors stimulated
Fever
elevation of body temperature. inhibits the growth of some bacteria and viruses. can become dangerous to the body if temperatures get to 44-45.
Transmission of Pathogens
- direct or non-direct contact
- transfer of body fluids
- droplets (sneeze)
- ingestion
- airborne
- transmission by vectors
Humoral Response
antibodies are specialised proteins (group: immunoglobulins)
Antigen- Antibody Complex
antibody attaches to a specific antigen which destructs the antigen.
Humoral Response Steps
- B cells in lymphoid tissue
- one type of B cell is sensitised, then enlarges and divides
- clones of B cells are formed
- most B cells become plasma and secrete antibodies and some B cells become memory cells
- antibodies combine with antigens to form antigen-antibody complexes
Cell Mediated Immunity Steps
location: intracellular fluid. targets bacterial and viral infections and cancer cells
1. B cell presents an antigen to a T cell
2. One type of T cell is sensitised, enlarges and divides
3. clones of T cell are formed
4. most T cells become Killer T cells which migrate to the place where large numbers of antigens are present. They attach to antigens and destroy them. Some become helper T cells which secrete substances that; sensitises more lymphocytes, attracts more macrophages and enhances phagocytosis
4a. some T cells become memory T Cells and some become Suppressor T cells which secrete substances that inhibit B and T cell activity after infection is over
Antibiotics
Used to fight infections of micro-organisms.
They work by blocking translation during protein synthesis of bacteria
Bactericidal
kills bacteria by changes or damaging the structure of their cell wall, allowing contents to leak out
Bacteriostatic
Stop bacteria from reproducing by blocking protein synthesis
Antivirals
treat viral infections only.
inhibit action of viral pathogens
target viral specific proteins and disable them or work by inhibiting the life cycle of the virus
enhance the body’s immune system to attack the virus
components of the immune system
lymph nodes, lymph vessels, lymphoid tissues and many leucocytes.
carries our specific and non-specific immune responses
self-antigen
materials recognised by the immune system as NOT belonging to the organism. stimulates an immune response
vaccine
artificial introduction of antigens into the body so the body has the ability to produce the appropriate antibodies without having to suffer the disease.
injection, oral, nasal spray
Herd Immunity
high proportion of population is immune to disease and they can protect vulnerbable others
non-self antigen
foreign compounds that trigger an immune response as it is not recognised by the immune system
First Line of Defence`
prevent entry into the human body and prevent reproduction
- skin- tough impervious barrier
- mucous membrane produce mucous which traps pathogens and debris
- hairs and cilia trap microbes
- gastric juice and vaginal secretions which can inhibit/ destroy microbes
- tears, sweat and saliva contain antibacterial properties
- cerumen (earwax) traps microbes and debris
- lysozyme kills bacteria in tears, sweat and nose secretions
Immune system
consists of lymph nodes, lymph vessels, lymphoid tissue and different leucocytes.
Lymphatic System
drains intercellular fluid back to the heart
Lymphocytes
WBC, involved in both specific and non-specific defence.
produced in bone marrow and some lymphoid tissue and circulate around the body
Macrophages
WBC, involved in both specific and non-specific defence.
large cells capable of carrying out phagocytosis
Vector
an agent (mozzie) capable of transferring a disease from one person to another.
Contagious
disease passed on by direct contact
Bacteria- Pathogen
Consists of a single cell, slime wall, DNA, cell membrane, flagella, cytoplasm and a capsule
Types: cocci, bacilli, spirilla, vibrio
Diseases Caused: chlamydia, whooping cough, gonorrhoea, dental cavities
Viruses- Pathogen
Consists DNA or RNA (never both). This is surrounded by a coat of protein.
Diseases Caused: HIV, chicken pox, ebola
Broad-Spectrum Antibiotics
work on a wide range of bacteria
Narrow-Spectrum Antibiotics
work on specific types of bacteria
