Flashcards in Chapter 5 + 6 + 7 Deck (24):
Name and describe 2 viral diseases
-Spread by inhalation of droplets from coughs and sneezes
-Symptoms include a fever and a red skin rash
-Can cause blindness and brain damage
-There is no treatment for measles but vaccination is possible
-Only causes mild flu-like symptoms and remains hidden in the immune system sometimes for many years to the point where the immune system becomes so damaged that it can no longer deal with infections
-Spreads through sexual contact or exchange of body fluids such as blood
-There is no cure or vaccination against it
Name and describe 2 Bacterial diseases
-Bacteria living in the gut of many animals, when raw meat or poultry is consumed by humans they can be infected
-The salmonella bacteria disrupt the balance of natural gut bacteria
-To most people symptoms develop from 8-72 hours of consuming the food, symptoms include: abdominal cramps, fever, vomiting and diarrhoea
-Salmonella can be treated with antibiotics and vaccinations exist
-Sexually Transmitted Infection
-In beginning relatively symptomless but some early symptoms include a thick yellow or green discharge from private parts and pain during urination
-10% of men and 50% of woman experience no symptoms at all
-Long term problems may be: long term pelvic pain, infertility and ectopic pregnancies
Name and describe a fungal disease
Rose Black Spot:
-Affects rose leaves
-Causes purple or black spots to develop on leaves and potentially make them drop off
-Weakens plants due to less resources for photosynthesis
-Can be treated with chemical fungicides
Name and describe a virus caused by protists
-Mosquitos act as a vector for the disease
-Malaria reproduces sexually in the mosquito and asexually in the human body
-When drinking human blood the protist travels into the humans bloodstream where they travel around the human body
-It damages red blood cells and liver, can cause frequent fevers and shaking when the protist bursts out of the blood cells, this can be fatal
-If diagnosed quickly it can be treated by a combination of drugs but this is not always possible
How do white blood cells fight infections ?
-Ingest pathogens, killing them
-Produce antibodies that target the pathogens antigen, this neutralises the disease
-Memory lymphocytes are created that remember the antigen of the disease so the body can fight it off quicker next time it enters
How do vaccinations work ?
1) Either the weakened pathogen or just its antigen is inserted into the patient
2) The immune system fights of the disease and creates memory lymphocytes
3) Next time the patient gets the same disease, his/her memory lymphocytes will be able to quickly deal with the infection preventing any harmful effects
What are antibiotics and how do they work ?
Antibiotics are drugs used to kill off bacteria:
-Antibiotics such as penicillin kill bacteria whilst inside your body
-Usually consumed with a pill or syrup however if the infection is serious they may be inserted straight through the blood stream
-Some antibiotics kill all bacteria and others target specific bacteria
Where are drugs commonly extracted from ? Provide examples
-Digitalis and digoxin is extracted from foxgloves
-Aspirin comes from bark of a willow tree
-Penicillin extracted from the mould penicillium
What 4 criteria must be met for a drug to be considered "good" >
Effective: Must prevent or cure disease, alternatively it can just alleviate pain
Safe: Cannot be too toxic to have unacceptable side effects for the patient
Stable: Must be able to use under normal conditions and be stored for some time
In and Out: Must successfully travel into and be removed from your body once the work is done
How are new drugs developed ?
1) Scientists discover a new molecule that may be used to treat a disease
2) Preclinical testing takes place, this is where the medicine is tested on living cells, tissue and animals
3) Drugs that pass the Preclinical trials move onto the clinical trials. In the clinical trials drugs are first tested in low doses on healthy patients to make sure the drug is safe, then the drug is tried on some patients with the disease to see if the drug can cure the disease.
If the drug passes this it then moves onto further clinical testing to determine optimum doses
4)If the drug passes all these phases then the drug may be licensed and distributed if a suitable investor is found
What is a double blind trial ?
-A clinical trial where the actual drug is present along with a placebo
-Neither the researchers nor the patients know which one is real
-This eliminates all bias in order to prove that the drug is in fact effective and not just a result of the placebo effect
What is a communicable disease ?
A disease that can spread via a pathogen
What is a non-communicable disease ?
A non-infectious disease
What is a casual mechanism
A mechanism that explains how one factor influences another via a biological process
Give a reason why noncommunicable diseases are hared to fight
Affected areas have non-foreign antigens so the immune system cannot recognise what needs to fought
What is cancer ?
When cells begin to divide uncontrollably causing serious health issues such as blocking off blood flow
What are the 2 types of tumours? Describe them
-Growth of abnormal cells contained in one place
-Can grow very large very quickly causing pressure or damage to an organ
Malignant tumour cells:
-Can spread around the body, invading healthy cells and causing further health issues
What are some causes of cancer ?
-Genetic risk factors
-Result of mutations to the genetic material, can be caused by ionising radiation such as X-rays or UV light or chemicals such as asbestos or tar found in tobacco smoke
How can cancer be treated ?
-Use of radiation (often gamma rays) to destroy infected tissue
-Indiscriminate so can also kill healthy surrounding tissue
-Use of Chemicals to either:
--Stop cancer from spreading
--Cause dividing cancer to "self destruct"
-Currently being worked on to be as specific to cancer cells as possible
Why can cigarettes be dangerous ?
1) Carbon Monoxide carried by red blood cells rather than oxygen, this may cause breathlessness and tiredness due to the reduction in oxygen for respiration
2) Tar in tobacco can cause some mutations that cause lung cancer
3) Smoking during pregnancy can inhibit growth of a foetus causing stillbirths or disabilities to the child
4) Chemicals in tobacco smoke may cause cilia that clear out mucus, bacteria and dirt away from the lungs to be temporarily anaesthetised
5) Narrows blood vessels in your skin, ageing it
What is the difference between type 1 and 2 diabetes ?
-Type 1 diabetes is not caused as a result of an unhealthy lifestyle, it can be caused by a virus with a similar antigen to beta cells that produce insulin, causing the immune system to attack the cells, causing a lack of insulin and therefore diabetes
-Type 2 diabetes can be caused by an unhealthy lifestyle an occurs when the liver looses its sensitivity to the insulin hormone (insulin resistance) so the liver no longer reacts to the hormone and does not intake excess glucose
What are some harms of alcohol ?
-Ethanol harms the liver which intakes ethanol (a poisonous substance), may lead to the development of cirrhosis which is a disease that destroys the liver
-Carcinogenic so heavy drinkers are at greater risk of developing liver cancer
-Long term consumption can cause damage to the brain, making it soft and pulpy, loosing regular brain structure to the point that it cannot function normally
-Can cause damage to foetuses e.g. stillbirths, problems with brain, teeth, jaw, kidney liver etc. Ultimately may lead to fetal alcohol syndrome(FAS)
Name some forms of Carcinogenic radiation
-Ultraviolet light from the sun
-Radioactive materials found in soil, water and air
--Can also come as a result of accident in nuclear power station such as the 1986 Chernobyl crisis where a nuclear power station in Pripyat released lots of radioactive material and a nuclear cloud which spread across Europe
-Medical and dental X-rays