Chapter 22 - Lymphatic System and Immunity Flashcards
What is the lymphatic system also known as?
Lymphoid system
What is the primary function of the immune system?
Involvement of all body cells and tissues in immunity
Define immunity.
The ability to resist infection and disease
What are pathogens?
Organisms that cause disease, such as viruses, bacteria, fungi, and parasites
What is lymph?
Fluid like plasma, no plasma proteins
What do lymphatic vessels do?
Carry lymph from the peripheral tissues to veins
What are lymphoid tissues?
Connective tissues dominated by lymphocytes
What are lymphoid organs?
Organs where lymphocytes may form, mature or become activated
What is the primary role of the thymus?
Regulates T cell development and maturation
Where does T cell division occur?
In the cortex of the thymus
What is the spleen’s function?
Filters blood to remove abnormal blood cells and stores iron recycled from red blood cells
What does the immune response refer to?
The body’s reaction to infectious agents and other abnormal substances
What are the two types of immunity?
- Innate (nonspecific) immunity
- Adaptive (specific) immunity
What characterizes innate (nonspecific) immunity?
Present at birth and does not distinguish one threat from another
What are some examples of physical barriers in innate defense?
- Skin
- Hair
- Mucous membranes
What are phagocytes?
Cells that attack and engulf microorganisms and debris
What role do macrophages play in the immune system?
Large phagocytic cells that process foreign threats and present antigens
What are natural killer (NK) cells responsible for?
Immune surveillance and inducing apoptosis in virus-infected and cancer cells
What are interferons?
Small proteins released by tissue cells infected with viruses that trigger antiviral responses
What does the complement system consist of?
More than 30 special complement proteins that assist antibodies in destroying pathogens
What are the cardinal signs of inflammation?
- Redness
- Swelling
- Heat
- Pain
What is the role of mast cells in inflammation?
Activated by injury to release histamine and other chemicals, increasing capillary permeability
What triggers fever?
Pathogens that cause the hypothalamus to raise body temperature
Define antigens.
Chemical targets that stimulate an immune response
