Transcript Effect of Environmental Conditions on Heart Rate: Experimenting

Effect of Environmental
Conditions on Heart Rate:
Experimenting with Daphnia
AP Biology Lab 10
http://cfb.unh.edu/cfbkey/html/anatomy.html
Daphnia Heart Rate
http://ebiomedia.com/gall/classics/Daphnia/daphnia_behave2.html
Procedure
• Obtain 2 concave
depression slide
• Add a Daphnia to one
of the slides
• Top with inverted
second slide and
secure with rubber
bands OR cover slip
Heart Rate and Temperature
• Use culture dishes to set up baths of varying
temperatures
• Start with the coolest bath
• Count number of heart beats in 10 seconds
Effect of Temperature on
Metabolism
• Ectothermic animals
– Rate of metabolism dependent on
temperature
– Metabolic rate and activity increases
dramatically between 5 and 35C
“Q10”
• Increase in Metabolism expressed in
terms of “Q10”
– Rate of metabolic rate at one temperature
compared to the metabolic rate at a
temperature 10C lower
“Q10”
• Q10 = rate at higher temp.
rate at lower temp.
Q10 = [k2/k1]
k1 = heart rate at lower temp.
k2 = heart rate at higher temp.
Drug Effects on Heart Rate
• Nicotine—stimulant
– Increases heart rate and blood pressure
• Alcohol—depressant
– At first lowers blood pressure, but then
rebounds to increase blood pressure
• Caffeine—stimulant
– Increases heart rate and blood pressure
• Aspirin
– Decrease heart rate and blood pressure