Chapter 4.1 Communicable Diseases Flashcards
What’s a pathogen ?
1
A microorganism that causes disease
What are the 4 main pathogens?
4
- bacteria
- Fungi
- virus
- protoctista
What is the pathogen life cycle ?
4
- transmission
- enter hosts tissues
- reproduce
- leaves hosts tissues
Name the types of direct message transmission ?
4
- direct physical contact
- fecal-oral transmission
- Droplet infection
- spores
What are some social factors that effect the spread of disease?
(5)
- overcrowding
- poor ventilation
- poor health and diet
- homelessness
- living and working with people who migrated from areas where the disease was high
What is the life cycle of plasmodium ?
7
1- female anopheles mosquito sucks blood 2-plasmodium migrates to the salivary glands of the mosquito 3-uninflected person bitten 4-plasmodium migrates to liver 5-plasmodium migrates to blood 6-a person with malaria 7-gametes of Plasmodium in blood
Direct Transmission of plant pathogens?
3
1- entering roots
2-spores
3-fruit seeds / leaves
Why indirect transmission of pathogens in plants?
- insect attack
In what climate are pathogen easily spread ?
1
WARM / MOIST conditions
What is Callose ?
Large polysaccharide deposit which blocks Old phloem sieve tubes .
What is Tylose?
Balloon like swelling or projection which fills the Xylem Vessel
What are the physical defensive of a plant ?
7
- cellulose cell wall
- lignin
- waxy cuticle
- bark
- stomata closure
- Callose
- tylose
What are the chemical defenders of a plant ?
DAPHT
(5)
- defensins
- Alkaloids
- phenols
- hydrolytic enzyme
- terpenoids
What’s a terpenOID ?
Oid ?
- essential oil ( antibacterial / antifungal)
What’s a phEnol?
(3)
Alcohol - chemical ?
Release chemicals which deactivate enzymes ie : tyrpsin
Tannins - inhibit arrack by insect
What’s an alkaloid ?
3
- bitter taste ie: caffeine
- stops animals from eating it
- inhibits protein synthesis
What’s a defensin ?
(3)
DETOL LIKE
- small cysteine rich proteins
- antimicrobial
What’s a hydrolytic enzyme ?
-ie :chitinase break down cell walls !
What are the ACTIVE defences of a plant ?
6
- increasing physical defences
- cell wall thickened
- deposition of Callose
- Oxidative bursts
- production of chemicals
- Necrosis
What’s Necrosis ?
1
- deliberate cell suicide
Primary defended against disease ( non specific ) ?
8
1-skin 2-blood clotting and skin repair 3-mucous membranes 4-coughing and sneezing 5-inflammation 6-other Ie : >eyes ( antibodies /enzymes in tears) >ear wax >female reproductive system ( mucous plug and acidic conditions in Vagina)
Outline how the skin is a defence ?
6
- physical barrier
- epidermis BASE ( keratinocytes- which divide by Mitosis )
- when keratinocytes migrate to the TOP :
- cytoplasm dries out and is replaced with KERATIN
- KERATINISATION
- so layer of top cells = DEAD
How does a blood clot form ?
10
1-injury to blood vessel release clotting factors
2-platelets join up=collagen
3-prothrombin —> thrombin ( enzyme )
4-thrombin turns
Soluble fibrinogen—> insoluble Fibrin
5-Fibrin attaches to platelets=clot
6-RBC/ platelets trapped inside clot = PLATELET PLUG
7-enzyme cascade rises
8-clot dries out > shrinks > draws sides of cuts together
9-stem cells divide >new cells > new skin
10- repaired !
How does the inflammatory response occur ? 5
1-mast cell detects microorganism
2-Histamine —> releases ( capillary wall is more permeable )
3-Vasodilation/phagocytosis ( phagocytes move to blood plasma )
4-production of tissue fluid increases as phagocytes and blood plasma enter tissue
5-OEDEMA ( swelling )
What are Opsonins ?
Antibodies that act as handles
How do neutrophils remove pathogens ?
5
- bind to opsonin attached to antigen
- engulf pathogen (endocytosis)
- lysosomes Fuse to phagosome
- lytic enzyme released
- after digestion , harmless products absorbed
Why are macrophages important?
2
- travel in blood as monocytes and are able to be ANTIGEN PRESENTER CELLS = specific immune response
What do APCS DO ?
1
Increase the chance of antigen coming in contact with B /T lymphocyte
Outline the specific immune response ?
3
1-activation of B/T cells = CLONAL SELECTION
2-production of antibodies combat specific antigen
3-hormones cytokines stimulate differentiation , activity if macrophages B and T cells
What’s an antibody ?
Specific protein released by plasma cells that can attach to pathogenic antigens
What does a B memory cell do ?
- remain in blood for long time and provide long term immunity
What does an interleukin do ?
It’s a signalling molecule which is used to communicate between WBCs
What does a plasma cell do ?
Manufacturer ANTIBODIES
What are the 4 T cells produces in immune response?
4
- helper
- killer
- memory
- regulator
What does a t helper cell do ?
- released cytokines to stimulate immune response
What does a T killer cell do?
- attack and kill host cells
What does a T memory cell do ?
- long term immunity
What does a T regulator cell do ?
- shut down immune response after pathogen is removed
What 2 B cells are produced in the immune response ?
- plasma cells
- B memory cells
What 3 chemicals are used in cell signalling.
- interleukin-stimulate clonal expansion
- Interferons -inhibits virus replication
- Monokines - attract neutrophils ( CHEMOTAXIS )
Outline activation clonal selection ?
3 main
3 details
- invading pathogen = specific antigens detected by T/B lymphocytes
- contact achieved when pathogenic cells enter lymph nodes or by action of APC
- CLONAL EXPANSION - correct lymphocyte activated and increases in number ( MITOSIS )
What are the 3 types of antibody ?
And what do they act as ?
(6)
- opsonins(handle )
- agglutins (glue - cross link pathogens )
- antitoxin ( make toxins harmless)
What’s the structure of an antibody ?
6
- 2 x light polypeptide chains
- 2x heavy polypeptide chain
- disulphide Bridges
- variable region for antigen binding
- constant region
- Hinge region
What’s a vaccination ?
A way of stimulating immune response so immunity is achieved
What can vaccines be made of ?
5
- whole live not as harmful organisms
- weak pathogens
- dead pathogen
- TOXOID ( harmless version of toxin)
- preparation of ANTIGENS from pathogen
What is RING VACCINATION?
Everyone around the site of the outbreak is vaccinated !
HERD VACCINATION ?
Enough people vaccinated to provide her immunity .
How do we control epidemics ?
3
- vaccination
- research
- monitor
What are the 4 different types of immunity?
4
- natural active/passive
- Artificial active / passive
Name natural active immunity?
- immune system first hand response to pathogen
Example of passive active ?
2
- placenta ( mum to baby )
- breast milk
Example of artificial active ?
1
- VACCINATION
Example of Artificial passive?
2
Snake bite ( antibodies injected into system )
How was penicillin found ?
- Alexander Fleming accidental discovery
- the fungus released compounds which killed bacteria !
Examples of traditional remedies?
3
- morphine sap from poopy seed
- opium (poppy seeds )
- Willow bark ( ASPIRIN )
Wildlife observations help medicine ?
4
- monkeys used CITRIC ACID = insecticide / antiseptic
- medicinal leaves in bird nests ( protect form blood sucking mites )
What can research into pathogens accomplish ?
4
- binding site for pathogen / virus / HIV = blocked ! Then it won’t have access to cells
- blocking DRUGS = stops virus from binding to receptor
