Health, Disease And The Development Of Medicines Flashcards
World health organisation definition of health
A state of complete physical, mental and social well-being, and not merely in the absence of infirmity.
Disease
A condition where part of an organism doesn’t function properly.
Communicable disease
Diseases that can be spread between individuals.
Noncommunicable diseases
Diseases that can’t be transmitted between individuals
How do diseases affect your susceptibility to other diseases?
Your body may become weakened by the disease, so it’s less able to fight others off.
Pathogens
Organisms that cause communicable disease.
Cholera pathogen and symptoms
A bacterium (vibrio cholorae) Symptoms include diarrhoea
Transmission and prevention of cholera
Spread via water.
Prevented by making sure people have access to clean water supplies.
Tuberculosis pathogen and symptoms
A bacterium (mycobacterium tuberculosis). Symptoms include coughing and lung damage
Tuberculosis transmission and prevention
Spread via droplets in the air.
Prevented by the infected avoiding public spaces, practicing good hygiene and sleeping alone in well ventilated homes.
Malaria pathogen and symptoms
A protist which damages red blood cells and sometimes liver.
Transmission and prevention of malaria
Animal vectors (mosquitoes) passing on disease to humans while being immune. Use of mosquito nets and insect repellent deter mosquitoes.
Stomach ulcers pathogen and symptoms
Bacterium called helicobacterplyori
Causes stomach pains, nausea and vomiting
Transmission and prevention of stomach ulcers
Spread via oral transmission (food and drink)
Prevented by having clean water supplies and hygienic living conditions
Ebola pathogen and symptoms
Virus
Symptoms include haemorrhagic fever (fever with bleeding)
Transmission and prevention of Ebola
Transmitted by bodily fluids
Preventing by isolating infected and sterilising places where bacteria is present.
Chalara ash dieback pathogen and symptoms
Fungus
Symptoms include leaf loss and bark lesions
Transmission and prevention of chalara ash dieback
Transmission via air (wind) and movement of trees
Prevented by removing young, infected trees and replanting with different species as well as restricting the import of ash trees
What do viruses have to do in order to reproduce?
Infect living cells
Lytic pathway
Virus attaches itself to a specific host cell, injecting its genetic material inside the cell.
Proteins / enzymes are used to replicate genetic material and produce components of new viruses which then assemble.
The host cells bursts/splits open releasing new viruses that infect new cells.
Lysogenic pathway
Virus’ genetic material is incorporated into the genome of the host cell and then is replicated with every time the host sells divides. Virus is dormant and no new viruses are made.
Eventually a trigger (eg the presence of a chemical) causes the viral genetic material to leave the genome and enter the lytic pathway.
STI
Sexually transmitted infection
Chlamydia pathogen and symptoms
Caused by a bacterium which behaves similarly to a virus.
Doesn’t always display symptoms but can cause infertility.
Transmission and prevention of chlamydia
Transmission via sexual contact
Prevented by wearing a condom, getting screenings or avoiding sexual contact
HIV (Human immunodeficiency virus) pathogen and symptoms
Virus that kills white blood cells, leading to the shutting down of the immune system. Leads to AIDS (acquired immunodeficiency syndrome) meaning the person is v vulnerable to other pathogens.
Transmission and prevention of HIV
Spread via bodily fluids.
Prevented by using a condom, not sharing needles, screenings and treatment
Plants physical defences against pathogens and pests
WAXY CUTICLE, providing a barrier for pathogens not to enter or damage them and meaning water can’t collect on the leaf and transmit waterborne pathogens.
CELL WALLS made from cellulose form a barrier against pathogens that make it past the waxy cuticle
Plant’s Chemical defences against pathogens and pests
Production of ANTISEPTICS which kill bacterial and fungal pathogens and chemicals that can deter pests from feeding.
Things like quinine (treatment for malaria) and aspirin (relief of pain and fever) are chemicals from plants.
Detection of plant diseases in the field
Plant pathologists can observe and identify symptoms (eg. Galls may indicate Crown gall disease).
They can also analyse the distribution of diseased plants to identify pathogen involved, (eg patches may suggest soil transmission whereas random distribution may suggest airborne pathogens)
How do plant pathologists tell that symptoms aren’t down to environmental factors?
They change the environmental conditions and observing any change in the plant’s symptoms.
Diagnosis of plant disease in the lab
Detection of antigens- antigens can be detected on a sample of plant tissue( using monoclonal antibodies).
Detection of DNA- scientific techniques can identify small traces of a pathogens DNA in a sample of plant tissue
Human physical barriers against disease
SKIN is a barrier, if damaged BLOOD CLOTS seal cuts and keep microorganisms out.
HAIRS/MUCUS in youR nose trap pathogens
EPITHELIAL CELLS (cilia) waft mucus (produced by cells) to back of throat to be swallowed into stomach acid.
Human chemical barriers against pathogens
HYDROCHLORIC ACID in stomach kills most pathogens that are swallowed.
LYSOZYME (in tears) kills bacteria on surface of the eye
B-lymphocytes
A type of white blood cell that’s involved in a specific immune response.
Process of specific immune response
B lymphocytes come across antigens and produce antibodies that bind to the new invading pathogen so it can be found and destroyed by other white blood cells. These antibodies are SPECIFIC to that pathogen.
Antibodies are then produced rapidly and flow all around the body to find similar pathogens.
Antigen
Unique molecule on the surface of pathogens
Antibodies
Proteins that bind to and identify new, specific, invading pathogens so that they can be killed by other white blood cells.