4.1 communicable diseases Flashcards
What are the types of primary responses
- lysozymes (tears)
- cilia and mucous membranes
- skin
- expulsive reflexs
- ear wax
- stomach acid
- blood clotting
Types of expulsive reflexes
- coughing
- sneezing
- vomiting
- diarrhea
Why are primary defences non-specific
they act the same towards all pathogens
Why is it important that blood clots do not form in the blood vessels
it would reduce the blood flow around the body, this reduces oxygen to the site
Role of a neutrophils
- multi-lobed nucleus which allows them to change shape
- short lived
- large numbers are released during infections
- move around actively and leave the blood
- mini
Role of macrophages
- travel in the blood as monocytes (unactive form)
- long lived
- initiate immune response
- antigen cell presenting
- line passages and alveolar walls
- big
Stages in phagocytosis
- chemotaxis and adherence of microbe to phagocyte (opsonin)
- ingestion of microbe (endocytosis)
- formation of a phagosome (vesicle)
- fusion of a phagosome with a lysosome to make a PHAGOLYSOSOME
- digestion of ingested microbe
- formation of residual body
- discharge of waste through exocytosis
Definition of opsonins
proteins that can bind to the antigen on a pathogen which allows phagoctyes to bind to the pathogen and engulf it
What is a major histocompability complex (MHC)
when the macrophage has digested a pathogen and combines the antigens from the pathogen with special gyloproteins in the cytoplasm
Types of bacterial disease
- bacterial meningitis
- tuberculosis
- ring rot
Types of viral disease
- HIV/AIDS
- influenza
- TMV(tobacco mosaic virus)
Types of protoctisa disease
- malaria
- potato blight
Types of fungal diseases
- black sigatoka
- ringworm
- athlete’s foot
What is tuberculosis caused by
Mycobacterium tuberculosis and M.bovis
Side effects of tuberculosis
- damaging lung tissue
- supressing the immune system
- chronic cough
How is tuberculosis spread
through the air - coughing/sneezing
What is bacterial meningitis caused by
Neisseria meningitidis
Side effects of bacterial mengingitis
- inflammation to the brain
- fever
- headache
- septicaemia
How is bacterial meningitis spread
through the air
Side effects of ring rot
- prevents water transport
How does ring rot spread
vascular infection of daughter tubes
Characteristics of viruses
- non-living and acellular
- consists of genetic material, capsid and attachment proteins
- replication occurs inside the host cell
Side effects of HIV (human immunodeficiency virus)
- chills
- rash
- night sweats
How is HIV spread
through sharing bodily fluids ie. blood
Side effects of influenza
- high temperature
- headache
How is influenza spread
through the air - coughing/sneezing
Side effects of TMV
- mosaic pattern
- stunting growth
- yellow spotting
Characteristics of a protista
- eukaryotic
- single-celled
- pathogenic protists are called parasistes (transmitted by a vector)
How is TMV spread
- contaminated tools/hands
- infected leaf rubbing against healthy leaf
What is malaria caused by
plasmodium
(spread by female mosquitos)
Side effects of malaria
- yellow skin
- diarrhea
- sore throat
How is potato blight spread
spores break away from the plant and are blown away
Characteristics of fungi
- eukaryotes
- either multi-cellular or single- cellular
- release enzymes that digest the host tissue
What does black sigatoka infect
bananas
Side effects of black sigatoka
- leaves turn black
- photosynthesis is stopped
How is black sigatoka spread
- wind borne spores
Side effects of ring worm
white crusty circle on the skin
How is ring worm spread
contact with infected organism
Side effects of athletes foot
white patches and cracked skin, normally between toes
How is ring worm
spread
contact with infected skin
Characteristics of bacteria
- prokaryotic
- classified by their shape or cell wall structure
- either gram-positive or gram-negative
Plant response
- anitbacterial chemicals - repel and kill pathogens
- physical defences - prevent pathogens from spreading
Where are B lymphocytes made and matured
both made and matured in the bone marrow
Where are T lymphocytes made and matured
made : bone marrow
matured : thymus
Role of B plasma cells
release specific antibodies
Role of B memory cells
immunological memory
Role of T helper cells
- release cytokines which stimulates B cells to develop
- stimulates phagocytosis
Role of T killer cells
- attack and kill infected host body ells which display the foreign antigen
- releases perforin
Role of T memory cells
immunological memory
Role of T regulator cells
- shut down immune response
- prevent autoimmunity
Process of cell mediated immunity
- either the antigen is displayed on a macrophage APC or pathogen inside an infected cell
- T helper cell is complementary to the antigen and it binds using receptors on the cell surface
- The binding is called CLONAL SELECTION
- This triggers the T helper cell to release interleukins triggering clonal expansion of B + T cells through differentiation and proliferation
Process of humoral immunity
- Pathogen is detected by B cells in bodily fluid
- B cell displays antibodies on their cell surface membrane
- B cell binds to complementary antigen
- T helper cell binds to complementary B cell antigen
- T helper cell releases interleukin which causes CLONAL EXPANSION = differentiation and proliferation
- B cell divides into B plasma and B memory cells
What is natural active immunity
immunity provided by antibodies made in the immune system as a result of infection
( example: chicken pox)
What is natural passive immunity
antibodies provided via the placenta or breast milk
What is artifical active immunity
antibodies provided after a vaccination
(example: influenza)
What is artifical passive immunity
antibodies provided by injection made by another individual
(example: tetanus)
What are the two types of vaccines
- Herd = provide immunity to everyone at risk
- Ring = new case of disease is reported
Definition of vaccination
weakened or dead pathogen that is injected to trigger the production of antibodies to a specific disease
Antibody structure
- made up of 2 long polypetide chains (heavy) and 2 short polypeptide chains (light)
- chains held together by disulphide bonds (difficult to denature during fever)
- rest of molecule is called the CONSTANT region
- anitgen binding site is called VARIABLE region
What is aggultination
- one antibody can bind to two pathogens causing them to clump together
- pathogens can be engulfed at once
What is antibody opsonisation
- process where the pathogen is makred for engulfing and digestion by phagocyte
- forms an antibody-antigen complex
What is neutralisation
- anitbodies can act as antitoxins
- these bind to the pathogen or to the toxin in pathogens
- render pathogens harmless
