B2 Flashcards
What are symptoms of a disease caused by?
Toxins that micro-organisms produce damage cells
Describe and explain the rate at which micro-organism can reproduce in the body
In the correct conditions( with warmth , moisture and nutrients) bacteria can multiply rapidly . The human body provides these conditions
Describe the two roles white blood cells protecting the body against disease.
They engulf and digest micro-organisms and also produce antibodies
Describe how antibodies recognise micro-organisms
Antibodies recognised micro-organisms by the antigens that the micro-organisms (pathogen) carries on its surface. Each antibody will fit a specific antigen
Why are different antibodies needed for different micro-organism?
Because antibodies are specific to certain antigens therefore for every different pathogen a different antibody is needed
Once a body has made the antibody they recognise a particular on a particular micro-organism, why can the body respond so quickly?
Memory cells can make the anti body very quickly and protect the body against the pathogen
Describe what immunity means?
Immunity is achieved when the body can produce antibodies (from memory cells) quickly enough to stop the micro-organism reproducing and reaching dangerous levels
How do vaccinations provide protection from micro-organisms?
They establish memory cells which produce antibodies quickly upon infection
What is a vaccine made from?
A safe form or a disease-causing micro-organism.
Why is it necessary to vaccine a high percentage of the population ?
To prevent epidemics of infectious diseases
Why can vaccines and drug never be completely risk free?
Because people have varying degrees of side effects to them.
Why do people react differently to drugs and vaccines ?
Because they have different genes
What are antimicrobials used for?
They are used to kill or inhibit bacteria and fungi
Antibiotics are a type of antimicrobial: what are they effect against and what are they not effect against?
They work against bacteria and fungi but not viruses
Over a period of time , bacteria and fungi may become resistant to antimicrobials; what does this mean for the effectiveness of the antimicrobial?
It means the antimicrobials are not as effective or will not work at all
How can micro-organisms become resistant to antimicrobials?
Random changes (mutations) in their genes lead to varieties that are less affected by the antimicrobials
What two things can we do to reduce antibiotic resistance?
We should only use antibiotics when necessary and always complete the course.
How are new drugs and vaccines tested for safety and effectiveness?
They are only tested on animals and human cells grown in a laboratory
Which two groups of people might new drugs and vaccines be tested upon and why?
Healthy volunteers to test for safety and on people with the illness to test for safety and effectivness
Explain what an open label trial is, and why it might be used ?
In an open trial the patient and doctor both know the treatment.This type of trial happen when there is no other treatment and the patients are so ill that doctors believe they will not recover from their illnesses.
Explain what a blind trial and why it might be used?
In a blind trial the volunteers do not know which group they are in but the researchers do . The problem is the researchers may give away clues to the volunteers without realising it . This is called observers bias, it makes the results unreliable.
Explain what is meant by an double blind? and why it might be used?
Neither the volunteers or researchers know what drug is being take , until the end of the trial. This removes the chances of bias and makes the results more reliable. But double blind trials are more complicated to set up.
Why is it important to conduct long term human trials?
Side affects must be studied over a long period of time;the drug needs to be tested on many different people.
What is a placebo?
A fake-drug that no affect on the patient
Why might it be deemed unethical to use placebos in human trial?
Many doctors do not like giving a placebo to patients with diseases because they feel the patient will not benefit from taking a fake drug and will not feel better. They do not think this is fair to the patient
The heart is a double pump; what does this mean ?
It has two sections that pump blood to different place (lungs and the rest of the body)
Why do heart muscles need their own blood supply?
The heart require its own constant blood supply in order to keep beating. (the cells need to respire to release energy for the pumping)
How is the structures of arteries related to their function?
Blood in the arteries is under high pressure generated by the heart.So they have thick outer walls and thick layers of muscle and elastic fibres.
How is the structure of the vein related to their?
The blood in the vein travel under low pressure, this is why the veins have thin walls and thin layers of muscle and elastic fibres.Veins also have one-way valves in them to keep the blood moving in the correct direction
How is the structure of the capillaries related to their function?
Capillaries allow food and oxygen to diffuse to cells whist allowing waste to diffuse from cells =. They have thin walls; one cell thick , to allow them to effectively perform their function
How can heart rate be measured?
By recording pulse rate
What do blood pressure measurement record?
They record they pressure of the blood on the walls of the artery
Blood pressure is given as two number , what do they represent?
The higher value is the heart contracting, the lower value is the heart relaxed
Why are ‘normal’ measurement for factors such as heart rate and blood pressure given with a range?
Because individuals vary
How is a heart attack caused?
- Fatty deposits build up n the coronary arteries
- A blood clot can form on a fatty deposit
- The blood clot can block a coronary artery]
- Some hearts muscle cells do not get the oxygen and nutrients they need
- These cells start to die
Is a heart disease always genetic? Explain?
No. it can be genetic but can also be caused by lifestyle factors
Give four lifestyle factors that can increase the risk of heart disease?
- Poor diet
- Stress
- Cigarette smoking
- Misuse of drugs
Give five ways in which the risk of heart disease can be reduced?
- Healthy diet
- Reduced stress
- Not smoking
- Not misusing drugs
- Regular moderate exercise
How do the rates of heart disease between industrialised and non-industrialised countries vary?
Industrialised countries have higher rates of heart disease to to diet and lack of exercise
How are the factors that can increase the risk of heart disease being identified?
From the epidemiological and large-scale genetic studies.
What is the link between blood pressure and heart disease?
High blood pressure increases the risk of heart disease.
How can the misuse of drugs ( Ecstasy, cannabis, ) affect the heart?
They can affect the heart rate, blood pressure and so increase the risk of a heart attack.
Which two body systems are involved in maintaining a constant internal environment (homeostasis)?
The nervous system and hormonal communications system
What is homeostasis?
The maintenance of a constant internal environment
What is the role of the receptor?
Receptors detect changes in the environment
What is the role of the processing centres?
They receive information and coordinate responses automatically
What is the role of effectors?
Effectors produce the response from the body.
What does the term ‘negative feed’ back mean?
Used to describe how the body reverses any change to the systems steady state.
How are receptors and effectors involved in negative feedback?
The effectors and receptors reverse any change to the system steady state.
why is a balanced water system important in the body?
It is important for maintaining the concentration of cell contents at the correct level for cell activity
Identify 3 ways in which the body gains water?
From drinks , food and respiration
Identify 4 ways in which the body loses water?
From sweating, breathing faeces and the excretion of urine
What is the role of the kidneys in the body?
Kidneys balance levels of water, waste and other chemicals in the blood.
Explain how the kidneys balance the water levels
By producing dilute or concentrated urine as a response to concentration of blood plasma, which is affected by external temperature, exercise level and intake of fluids and salt.
Which hormone controls the level of urine and where is it released from?
ADH ( Anti Diuretic Hormone) controls the levels of urine and it is secreted by the pituitary gland into the bloodstream
Explain how ADH secretion is controlled by negative feedback ?
ADH is produced by the pituitary gland that is situated just below the brain. The pituitary glad monitors the concentration of the blood plasma. It releases ADH into the bloodstream, which travels I the blood to the kidneys. The more concentrate the plasma, the more ADH is released into the blood . When the ADH reaches the kidneys , it causes them to absorb more water . This keeps more water in the body and produces more concentrated urine.
When the plasma is more dilute, less ADH is released into the bloodstream.This allows more water to leave the kidneys producing more dilute urine.
This is an example of negative feedback.
Explain how alcohol affects water levels on the body?
Alcohol suppresses ADH production. This causes the kidney to produce more dilute. It can lead to dehydration.
Explain how the drug Ecstasy affects water levels on the body?
Ecstasy increases ADH production. This cause the kidneys to reabsorb water . it can result i the body having too much water.
