Ch. 37 - The Human Defence System Flashcards
What is a pathogen?
A pathogen is an organism that causes disease.
What is immunity?
Immunity is the ability to resist infection.
What is the general defense system?
The general defense system acts as a barrier to all pathogens attempting to gain entry to the human body.
What is the specific defense system?
The specific defense system also known as the immune system attacks particular pathogens using antibodies or by killing infected cells.
Detail the role of the skin in the general defense system.
The skin is a physical barrier preventing the entry of pathogens.
Detail the role of blood clotting in the general defense system.
If the skin is broken, platelets clot to prevent entry of pathogens.
Detail the role of lysozomes in the general defense system.
Lysozomes are an enzyme found in sweat and saliva that attack pathogens (by dissolving their cell wall).
Detail the role of sebaceous glands in the general defense system.
Sebaceous glands produce sebum which kills pathogens.
Detail the role of mucus in the general defense system.
Mucus traps pathogens and are denied entry in this way.
Detail the role of cilia in the general defense system.
Cilia beat upwards to move mucus back up the respiratory system to be coughed out.
Detail the role of acid in the general defense system.
HCl in the stomach kills pathogens.
Detail the role of bacteria in the general defense system.
Bacteria in the vagina produce lactic acid preventing the growth of pathogens.
What are phagocytes?
Phagocytes are white blood cells that surround and ingest pathogens. Large phagocytes are called macrophages.
Name 2 sets of defence proteins.
Complement(set of 20 proteins) and interferons(prevent viral multiplication).
What do monocytes develop into?
Monocytes develop into macrophages.
What is an antigen?
An antigen (antibody generator) is a foreign molecule that stimulates the production of antibodies.
What is an antibody?
An antibody is a protein produced by lymphocytes in response to a specific antigen.
What is induced immunity?
Induced immunity is the ability to resist disease caused by specific pathogens by the production of antibodies.
What is active immunity?
Active immunity involves the production of a person’s own antibodies in response to antigens that enter the body.
What is a vaccine?
A vaccine is a non disease causing dose of a pathogen which triggers the production of antibodies. This induces artificial active immunity. A vaccination is a vaccine’s administration (by injection).
What is passive immunity?
Passive immunity occurs when individuals are given antibodies that were formed by another organism. This gives short term resistance to infections.
Differentiate between natural and artificial passive immunity.
Natural passive immunity occurs when a child gets antibodies from their mother. Through the placenta or by breastfeeding. Artificial passive immunity is done by injection.
What is immunisation?
Immunisation occurs when we produce or are injected with antibodies against a pathogen. Vaccination results in immunisation.
What is a plasma B cell?
A plasma B cell produces antibodies. They mature in bone marrow.
What is a memory B cell?
A memory B cell survives long after infection and makes the specific antibody if the same pathogen later enters the body. They mature in bone marrow.
What is a helper T cell?
A helper T cell stimulates B cells and killer T cells. They mature in the thymus gland.
What is a killer T cell?
A killer T cell destroys abnormal human body cells. They mature in the thymus gland.
What is a suppressor T cell?
A suppressor T cell inhibits the immune response. They mature in the thymus gland.
What is a memory T cell?
A memory T cell survives long after infection and stimulates B cells and killer T cells if the same pathogen later enters the body.
Name organs in the human body that are specific to the defense system.
Thymus, spleen, lymph nodes, tonsils.
