Disease and Immunity Flashcards
Define and identify examples of pathogens
Pathogens are micro-organisms that cause disease.
Like most bacteria and all viruses
Describe the common features of bacteria
The flagella helps it move Plasmids carry some genes DNA carry all information Cell wall holds its shape Cell membrane Cytoplasm is wheres chemical reaction take place
Describe the common features of viruses
DNA surrounded by a protein coat
No nucleus or cytoplasm
Either circular and flat or cylindrical
Describe the common features of fungi
Can be unicellular or multicellular
Cell walls are made of chitin
Multicellular fungi contain hyhpae
Saprotrophic nutrition
Describe the common features of protoctists
Can be unicellular or microscopic
There are plant and animal like varieties
Plant like varieties photosynthesise
Reproduce asexually
How do platelets work
These are found inside the blood
When there is a cut, the platelets clot around it so that no bacteria can enter and no blood is lost
How does the immune system respond to disease
There are two types of white blood cell- phagocytes and lymphocytes.
Phagocytes engulf and digest the bacteria. They do this by changing shape and then surrounding it. It then uses strong enzymes to break it down.
Lymphocytes make antibodies which are specific to the antibodies antigen. These then stick to the pathogen and send out signals to the phagocytes. Some of these antibodies are kept as memory cells.
What does vaccination do
In vaccination, they inject dead or weakened pathogens into the body. Before they cam=n do any damage the phagocytes have destroyed them and the lymphocytes have made “memory cells”. Then when the same pathogen invades the body, the lymphocyte can use the memory cells to make loads of antibodies in a short space of time.
What are the consequences of smoking
Nicotine is found in tobacco and is an addictive drug. This makes it very hard to give up smoking. Carbon monoxide reduces the amount of oxygen carried in the blood of smokers. It also combines with the haemoglobin which would instead be carrying oxygen.
What is emphysema
The walls of the alveoli are thin and weak
Coughing results in the bursting of some of the weakened alveoli
In the long term, this reduces the the lungs surface area available for oxygen absorption.
What is bronchitis
The cilia are destroyed by the heat of the cigarette smoke
Mucus is not wafted back up the trachea
Mucus collects in the bronchi and bronchioles
Bacteria grows in the mucus causing infection
This leads to inflammation called bronchitis
What factors may increase the risk of coronary heart disease
Making the blood platelets “sticky” so that they clump together.
This increases the rate of fatty material which is deposited in the arteries.
The arteries narrow which is dangerous if it happens in the coronary artery which supplies blood to the heart.
If your coronary artery gets blocked then it can cause death.
less glucose and oxygen can reach your heart.
The muscle respires anaerobically
Therefore less energy is released
The heart can no longer contract.
