Unit 5 - Immune System & Disease Flashcards
What is the role of the body’s first line of defense?
body’s first line of defense consists of different types of barriers that keep most pathogens out of the body.
Identify three types of barriers in the body’s first line of defense. Give an example of each type of barrier.
Mechanical ex) skin
Chemical ex) Tears
Biological ex ) Useful bacteria
What is a nonspecific defense?
A nonspecific defense is the same no matter what type of pathogen is involved.
What is the body’s second life of defense? When does it take effect?
Inflammatory response - when a pathogen gets passed the first line of defense
Identify the roles of nonspecific leukocytes in the body’s second line of defense.
role is to fight infections and get rid of debris.
Jera cut her finger. The next day, the skin around the cut became red and warm. Why are these signs of infection?
Because warmth and redness of indications of an inflammatory response
What is the lymphatic system?
System that involves the 3rd line of defense - the immune response
List three organs of the lymphatic system and their functions.
Bone marrow. It produces lymphocytes.
The thymus. It stores and matures lymphocytes.
The spleen. It filters pathogens and worn out red blood cells from the blood, and then lymphocytes in the spleen destroy them.
The tonsils .They trap pathogens, which are destroyed by lymphocytes in the tonsils.
What are lymph nodes? What is their function?
As lymph passes through the lymphatic vessels, pathogens are filtered out at small structures called lymph nodes.The filtered pathogens are destroyed by lymphocytes.
What are the two major types of lymphocytes?
B cells- mature in bone marrow, antibody or humoral immunity (they produce antibodies that kill)
& T cells - mature in the thymus, cell-mediated immunity (they physically kill pathogens)
What are antigens, and how do lymphocytes “recognize” them?
Antigens are molecules that the immune system recognizes as foreign to the body.
They have receptor molecules on their surface that bind only with particular antigens.
the fit between an antigen and a matching receptor molecule is like a key in a lock.
What is immunity? What role do memory cells play in immunity?
Memory B and T cells help protect the body from re-infection by pathogens that infected the body in the past. Being able to resist a pathogen in this way is called immunity.
How is active immunity different from passive immunity? Why does active immunity last longer?
Active immunity results when an immune response to a pathogen produces memory cells.
Passive immunity results when antibodies are transferred to a person who has never been exposed to the pathogen.
Explain how immunization prevents a disease such as measles, which is caused by a virus.
Immunization is the deliberate exposure of a person to a pathogen in order to provoke an immune response and the formation of memory cells specific to that pathogen
What is an allergen? Give two examples.
Any antigen that causes an allergy is called an allergen. Ex poison ivy, pet dander
