Chapter 32 Flashcards
What is an antigen?
-unique group of molecules of surface used to recognize them
What is immunocompetence?
-the ability to activate a response to a bad antigen
What are the two major categories of immune mechanisms?
- innate immunity
- adaptive immunity
Describe innate immunity. What is it called?
- in place before a person is exposed to an antigen
- called nonspecific immunity
- faster
What composes innate immunity?
- epithelial barrier cells
- phagocytic cells (neutrophils and macrophages)
- natural killers
- cytokines
Describe adaptive immunity. What is it called?
- recognizes specific threatening agents and adapt by targeting their activity against those antigens
- called specific immunity
- takes time, memory cells
What composes adaptive immunity?
- t cells
- b cells
What is species resistance?
- genetic characteristics common to a species that provide resistance to a certain pathogen
- every member of species is resistant
What makes up the first line of defense?
- mechanical: skin
- chemical barriers: sebum, mucus, enzymes, hydrochloric acid
What are the second lines of defense?
- inflammation
- fever
- phagocytosis
- NK cells
- interferon proteins
- complement system
What is inflammation?
- redness, pain, heat, swelling
- damaged tissue release chemotaxis that attract wbc
What are inflammation mediators?
- histamine
- kinis
- prostaglandins
- leukotrienes
- interleukins
What are the three stages of inflammation?
- vasodilation and increased permeability
- phagocyte emigration (creates pus; diapedesis)
- tissue repair
What is diapedesis?
-passage of blood clot through intact wall of capillaries
What is fever?
-state of abnormally high body temperature
What chemical causes fever?
-prostaglandins
What is phagocytosis?
-ingestion and destruction of microorganisms and small particles
Which white blood cells participate in phagocytosis?
- neutrophils
- macrophages (monocytes)
What are the different kinds of macrophages? Location?
- wandering
- fixed (skin, liver, lungs, nervous system, secondary lymph organs)
What are the five stages of phagocytosis?
- chemotaxis via diapedesis
- adherence
- ingestion
- digestion
- release/presentation
What is an antigen-presenting cell? Why are they important?
- after digestion of particle, a phagocyte displays bits of protein on its surface
- important bridge between innate and adaptive immunity
What are natural killer cells?
- lymphocytes
- kills tumor cells and cells infected with a virus
How do NK cells recognize abnormal cells? Function?
- killer-activating receptor: binds to any cell
- killer-inhibiting receptor: binds to the MHC (only self cells)
What is the major histocompatibility complex?
- MHC that identifies cell as “self”
- helps body not attack self
