INTRODUCTION
An experiment was conducted to study and explore the circulatory system by exposing Lumbriculus variegatus, black worms, to household drugs. Lumbriculus variegatus was chosen as the experimental organism because of their transparent bodies and their simple physiology.
Their transparent bodies help the experimenters to easily see their pulse. Another reason for choosing this specific organism is their body structure—large surface area to size ratio. This feature allows the substances, such as the household drugs, to easily enter their body which then can affect their health.(1) The household drugs used in this experiment were decaffeinated coffee, tea, instant coffee and tobacco along with caffeine and nicotine.
As we increase the concentration of caffeine, there will be an increase in the change in pulsation rates of the L. variegatus. The reason that the pulsation rate increases with the intake of caffeine is because it increases the blood flow velocity in the middle cerebral artery, which in a way increases the pulsation rates.(5) Caffeine is known as a stimulant, especially for the central nervous system; because “caffeine increases energy metabolism throughout the brain but decreases at the same time cerebral blood flow.”(4) Caffeine also acts as an inhibitor for adenosine, which is what allows it to be a stimulant.(2)
As we increase the concentration of nicotine, there will also be an increase and right after the maximum change in pulsation rates of the L. variegatus there will be a decrease which will eventually hit 0 beats per minutes. The reason the pulsation rate increases and then decreases with the intake of nicotine is because it causes an increase in heartbeats and with a large doze it can result to no heartbeat at all.(3)
Since decaffeinated coffee, tea, and instant coffee have caffeine in them there may be increase in the change of the pulsation rate of the
Cited: 1. The Effect of Common Household Drugs on Circulatory Functions. N.p.: Department of Biology, n.d. Print. 2. Fisone, G., A. Borgkvist, and A. Usiello. "Caffeine as a Psychomotor Stimulant: Mechanism of Action." Cellular and Molecular Life Sciences CMLS 61.7-8 (2004): 857-72. Ebsco Host. Web. 13 Mar. 2013. . 3. "MDCH Fact Sheet Nicotine: Nicotine Ingestion." Michigan.gov. N.p., n.d. Web. 13 Mar. 2013. . 4. Nehlig, Astrid, Jean-Luc Daval, and Gerard Debry. "Caffeine and the Central Nervous System: Mechanisms of Action, Biochemical, Metabolic and Psychostimulant Effects." Brain Research Reviews 17.2 (1992): 139-70. ScienceDirect. Web. 13 Mar. 2013. . 5. Sigmon, Stacey C., et al. "Caffeine Withdrawal, Acute Effects, Tolerance, and Absence of Net Beneficial Effects of Chronic Administration: Cerebral Blood Flow Velocity, Quantitative EEG, and Subjective Effects." PSYCHOPHARMACOLOGY 204.4 (2009): 573-85. Web of Knowledge. Web. 13 Mar. 2013. . 6. Snith, A. "Effects of Caffeine on Human Behavior." FOOD AND CHEMICAL TOXICOLOGY 40.9 (2002): 1243-55. Web of Knowledge. Web. 13 Mar. 2013. .