Please enable JavaScript.
Coggle requires JavaScript to display documents.
Module 7 infectious disease - Coggle Diagram
Module 7 infectious disease
Inq1: causes of infectious disease
pathogens
protozoan
prion
fungus
ectoparasite
virus
endoparasite
Bacteria
koch's postulates
identify
2.culture
innoclulate
re isolate and identify
re isolate individual
another sample is taken and cultured to identify if pathogen is present
introduce sample back into host, must develop same symptoms
grow sample into a later stage on an artificial medium
observe a sample of suspect pathogen in microscope
pasteurs experiments
swan neck flask
beef stew did not spoil when not exposed to microorganisms
replacement of spontaneous generation theory of disease
germ theory of disease
fermentation of wine due to yeast (microorganism)
spoilage of beer and wine due to microorganism
used germ theory to prove anthrax occurred from animal spores
cause and effects of disease on agricultural production
factors influencing
climate change
antimicrobial/pesiticide resistance
loss of genetic diversity
animal and plant diseases
cause
fungi, insects/mites, bacteria, nematodes, viruses, phytoplasmas
effect
biological effects on individual plant
social and economic effects on farmer and economy
inq2: response to pathogens
plant and animal immunity
induced
production and secretion of antimicrobial molecules
production and secretion of signalling hormones
third line of defence -> immune response (chemical responses by cells)
innate
cell wall and cuticle
antimicrobial bacteria (nicotine)
first line of defence -> physical and chemical barriers
second line of defence -> inflammation
inq3: immunity
#
second line of defence
internal physiological defences :
inflammatory response
pain, heat, swelling, redness, loss of function
tissue injury
signals for histamines
recruits phagocyte
then isolates site/pathogen
phagocytosis (cell eating)
phagocyte
A WBC which is responsible for phagocytosis
neutrophils and macrophages
modifies shape
envelops non specific antigen
foreign protein marker on cell surface
releases lysosomes
breaks down microbe/antigen
lymphatic system
contains WBC
fluid filtered through lymph nodes, pathogen is removed
drainage of fluid from bloodstream in nearby tissue
cell death (programmed)
caused by NK cell (lymphocyte)
NK release perforins and granzymes
kills neighbouring cells
creates wall of dead cells
surrounds infected cell
kills pathogen inside
layers
phagocytes
lymphocytes
fibre cells envelop structure
interferons
(virus)
proteinn screted
from cell infected with virus
induce neighbouring cells
produce antiviral chemicals
reduces protein synthesis of viral replication
neighbouring cells undergo apoptosis
complement proteins
produced by liver cells
travels through bloodstream
destroys extracellular pathogens
stimulate more phagocytes
tags pathogen for phagocytosis
binds antibody onto antigen
fever/pyrexia
pyrogen increases body temp
kills or limits growth of pathogen
enhance activity of WBC
strengthen immune response
may increase uncontrollably
negative effects on organism
non-specific and non adaptive
recognition of pathogens
Pattern recognition receptors (PRR)
recognises of pathogen specific molecules
Eg. bacterial cell wall components
PRR recognises PAMPS
pathogen associated molecular patterns
present on all cell surfaces
third line of defence
specific immune response
can recognise and defend against invading antigens
cell mediated response
T-lymphocytes
produced in bone marrow
matured in thymus gland
different types of T-lymph.
cytotoxic(killer)
activated by Helper T
travels towards infected cells
release cytokines to lyse infected cell
recognise MHC I molecule of infected cells
usually viruses
memory
when exposed to the same antigen
surface receptors protein remain the same
activate
clone and differentiate into
Helper T
Killer T
helper
recognises MHC II molecule
bound to an antigen fragment on phagocyte
secrete cytokines
activate C.M and H immune response
activates Cytotoxic T and B cells to specific antigen
suppressor
bind to antigens with receptor protein
suppresses (stops)
B Lymph + Kill T that recognise the same antigen
masks antigen
regulates ADAPTIVE immune response
required after infection is controlled
Major histocompatibility complex
group of genes that code for Proteins
help immune system recognise foreign substances
Class II
present in exogenous antigens
in antigen-presenting cells
macrophage, dendritic cell, activated B cells
Class I
present endogenous antigens from cytoplasm
present in all nucleated cells
humoral response
B cells/lymphocytes
specialised WBC
produced and matured in bone marrow
specific antibody
to specific antigen
move into lymph nodes
2 types
memory B cells
long lived
stored for info
plasma cells
produces antibodies
short lived
antibodies
Y shaped protein
consists of chains
two shorter lighter
two longer heavier
2 binding sites
specific to antigen
2 responses
primary
produces less antibodies than secondary
fast short lived
secondary
greater amount of antibodies produced
due to mem B and T cells
more rapid response
first line of defence
physical barriers
skin
saliva
tears
mucous membrane
cilia
chemical barriers
urinary and vaginal tract
inq4: prevention, treatment and control
Antibiotics
kills or limits growth of bacteria
most effective when
accessing the site of infeciton
killing rather than slowing
whole course is taken
used solely for bacterial infections
resistance
limits antibiotic effectiveness
antibiotic weakens over time
problems
Antiviral
viruses
use host cell to produce new virus particles
difficulty to create a antivirus which doesn't kill host cell
combination therapy
targets different cycles of the virus
enhances effectiveness of treatment
Prevention
quarantine
a period of time of isolation for an individual which has arrived from elsewhere being exposed to infections
borders open or closed?
vaccination
#
hygiene practices
engineering and water control
safe waste disposal management