L-30 Flashcards
(31 cards)
What is immunology?
The study of an organisms defence system in health and disease
What is the immune system?
An organised system of organs, cells, and molecules that interact together to defend the body against disease such as pathogenic microorganisms and cancer
Name the 5 organs of the immune system:
- tonsils
- thymus
- spleen
- bone marrow
- lymph nodes
What do primary lymphoid organs do?
They are responsible for the production of white blood cells (lymphocytes)
What do secondary lymphoid organs do?
They are sites where immune responses are initiated
What are the primary lymphoid organs?
- bone marrow
- thymus
What does the bone marrow do in the immune system?
Source of stem cells that develop into cells of the “innate” and “adaptive” immune responses
What does the thymus do in the immune system?
Acts as a “school” for white blood cells called T cells to learn not to react t themselves. Only 10% of T cells are released from the thymus and the rest are destroyed
What are the secondary lymphoid organs?
- Spleen
- Lymph nodes
What does the spleen do in the immune system?
The site of initiation for immune responses against blood-borne pathogens
What do the lymph nodes do in the immune system?
Filter lymph fluid from blood and tissue and it is a site of initiation of immune responses. Located along the lymphatic vessels
What are the 3 layers of immune defence?
- chemical and physical barriers
- innate response
- adaptive response
What are the physical barriers of the immune defence system?
- skin
- mucous membranes
What does the skin do in the immune system?
The skin provides a physical barrier that protects the body against pathogens
What is the outermost layer of the skin called?
Epidermis
What is the epidermis composed of?
- dead cells
- keratin
- phagocytise immune cells
What layer of the skin is deep to the epidermis?
Dermis
What is the dermis? What is it made of?
thick layer of connective tissue
- collagen
- blood vessels
- phagocytic immune cells
What are the chemical immune defences of the skin?
- antimicrobial peptides (skin defensins)
- lysozymes
- Sebum
- salty sweat
What do antimicrobial peptides do to aid the skin in protecting our immune system?
Form pores in microbial cell membranes
What do lysozymes do to aid the skin in protecting our immune system?
Break down bacterial cell walls
What does sebum do to aid the skin in protecting our immune system?
Low pH provides sub-optimal environment for microbe enzymes
What does salty sweat do to aid the skin in protecting our immune system?
Affects the osmoregulation of microbes
What are mucous membranes?
1-2 layers of tightly packed epithelial live cells that are constantly being renewed and replaced
