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BIO170 - Obj 6B
BIO170 - Objective 6 - Fever
| Question | Answer |
|---|---|
| What is the body's thermostat? | the hypothalamus |
| What is normal body temperature? | 37 deg Celcius; 98.6 Fahrenheit |
| What are thermoreceptors? | thermoreceptors are found throughout the body, both superficially and deep within the body core; they provide constand information to the hypothalamus |
| What are endogenous pyrogens? What is their function? | Endogenous pyrogens are produced by phagocytic white blood cells; they reset the hypothalamus to a higher set point |
| What is an example of an exogenous pyrogen? What is the most common? | produced by bacterial cells; most common are the lipopolysaccharides found in the cell walls of gram-positive microbes like streptococcus pyrogens |
| How is "strep" fever caused? | by the cell wall of the streptococcus microbe |
| What is the function of bacterial pyrogens? | they also reset the hypothalamus to a new, higher setpoint |
| What is the crisis response to fever? (4) | shivering thermogenesis, piloerection, vasoconstriction, and behavioral adaptation |
| Why do we shiver with fever? | with a new, higher set point, the body response is to generate heat; shivering is rhythmic tremors in muscle, which generates heat |
| What is piloerection? | "goosebumps"; during the "chills" stage of fever; this is more useful in animals as when the hair stands up, the air around the hair is warmed, warming the body |
| How does vasoconstriction warm the body? | the constriction of peripheral blood vessels shifts the majority of the blood flow into the body's core and away from the extremities where heat is easily lost |
| What are the actions of anti-pyretics drugs? | aspirin and Tylenol can temporarily reset the hypothalamus to a new, near-normal setpoint; makes the person more comfortable, but doesn't resolve the illness |
| What is resolution/regeneration of a fever? | involves the immue system; once the cause of the fever has been resolved (ex: the invading microbe has been destroyed), they hypothalamus can be returned to a normal set point by endogenous cryogens |
| How should a febrile patient be deressed? | a febrile patient should be minimally covered so as to prevent an excessive rise in body temperature |
| What is the purpose of fever? | fever suppress infection as microbes cannot multiply as rapidly at fever temperatures |
| Which mineral concentrations in the body are diminished by fever? | iron, zinc, and copper (in plasma); microbes need these to grow and multiply |
| What type of activity does fever increase? | activity of phagocytic leukocytes |
| How does fever make a person feel? | sleepy and anorexic (eat less); provides for rest and recovery |
| When does fever cause problems? | When it is uncontrolled |