Immunity Flashcards
What is a disease
A disease is a condition that prevents the body or part of the body functioning properly
What are the two main types of white blood cell ?
- phagocytes
* lymphocytes
What are phagocytes ?
They are type of white blood cell that engulf and Digest pathogens
What are pathogens ?
Micro-organisms that cause disease
What process occurs when a phagocytes kills a pathogen
Phagocytosis
Order of phagocytosis
- Phagocyte recognises the pathogen
- phagocyte engulfs the pathogen in a process known as phagocytosis where it extends its cytoplasm to engulf it (pseudopodia)
- the lysozymes containing enzymes move towards the pathogen
- enzymes break down pathogen
- useful materials are absorbed, and waste products are removed from the phagocyte
What are lymphocytes?
Lymphocytes are a type of white blood cell, that produce special Y shaped proteins called antibodies. These are attached to special structures on the pathogen called antigens
Where do you find antigens ?
On the pathogen
Where do you find antibodies ?
In a lymphocyte
What do lymphocytes allow organisms to do ?
Build up immunity towards certain diseases
Order of How lymphocytes destroy pathogens
• lymphocytes detect pathogen
• lymphocytes release many different types of antibody
• correct antibody connects to the pathogens antigen
• limit the site releases large number of correct antibody
—– lymphocytes can now do two things——
• pathogen is either clump together resulting into death or the antibodies trigger phagocytosis
• then lymphocytes produce cells that produce antibodies very quickly, these are called memory cells
How long to memory cells last?
A lifetime
How do you vaccines work ?
- The body is given a vaccine which is a dose of the pathogen normally by injection, this dose is normally a dead pathogen or part of the pathogens cell surface.
- This stops the pathogen from causing a disease
- lymphocyte generate antibodies against the pathogen and make memory cells
- this way vaccines can give us immunity
What are the defence mechanisms for disease in the body ?
- lysozyme in tears
- skin
- muchus lining trachea
- urine
Order of blood clotting
- injured tissues and platelets released the clotting factor - prothrombin activator and calcium ions
- prothrombin activator converts the blood protein to thrombin
- thrombin splits fibrinogen to form fibrin
- fibrin fibres form and mash over the wound, trapping red blood cells and platelets
- bleeding stops, clot hardens and become smaller
- New cells grow to repair the wound site
- enzyme plasmin is released to dissolve clot