In this lab, we assessed the impact of varying tensions and neurotransmitters on the heart’s rate and contractility. Prior to conducting the experiment, we hypothesized that the more the heart muscle stretches, the greater the force of contraction will be and that if a neurotransmitter can act on a muscarinic and nicotinic receptor without an antagonist present, the agonist will produce a parasympathetic (decrease in heart rate) and sympathetic response (increase in heart rate and contractility) respectably. After conducting the experiment, we can say with certainty that the majority of our results correspond with our hypothesis and the parts that don’t can be explained by human error; therefore, we must accept it.
For starters, the results
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In Figure 27, there is an increase of 10.3 % while there is an increase of 161.9%. Both demonstrate an anticipated increase in heart rate; however, the expected heart rate is substantially greater. This discrepancy is possible due to the numerous cold experimental treatments prior, the atropine being cold, and the control that the experimental group is being compared. Depending on the accuracy of the control, the experimental group can demonstrate either a positive or negative chronotropic response. It is also possible that dosage was the issue. According to a therapeutic review study conducted on bradycardia patients, a condition where the heart beats abnormally slow, atropine was administered to increase heart rate and improve atrioventricular conduction it was found that in small doses, atropine actually has a paradoxical effect on the heart. Instead of increasing heart rate, it will instead decrease heart rate (Das, 1989). Hence, it is possible that not enough of the atropine was administered uniformly along the surface of the heart or at least along the pacemaker region to produce an effective increase in heart …show more content…
To improve this experiment, a better control for the experimental treatments needs to be established. Instead of comparing the experimental treatment against cold saline, a baseline period needs to be taken prior to the application of any experimental conditions. In addition, each experimental treatment should be conducted on a different frog of the same mass and health or at the very least on the same frog after ample recovery time has been given and the heart beat has stabilized instead of consecutive experimental treatments. Also, the temperature of the treatments and dosages of each neurotransmitters need to be standardized to prevent any discrepancies or
Prior to intubation for a surgical procedure, the anesthesiologist administered a single dose of the neuromuscular blocking agent, succinylcholine, to a 23-year-old female to provide muscular relaxation during surgery and to facilitate the insertion of the endotracheal tube. Following this, the inhalation anesthetic was administered and the surgical procedure completed.
The procedure starts with the preparation of the frog and the set-up of the equipment. During the remainder of this lab, continuous
The controlled group was left with 0 nicotine applied. The 4 treatment groups were treated with 4 different levels of nicotine concentrations: 25 µm, 50 µm, 75 µm, and a 100 µm. The treatment concentrations were applied on top of the pond drop that the Daphnia Magna’s were trapped in on the depression slide; a minute was given for Daphnia Magna acclimation with the treatments. Then, the heart rate of each of the 3 Daphnia Magna’s in the 5 groups was measured, 3 Daphnia Magna’s were tested in each group to attain the mean so that more accurate results were reached. The technique used was that we counted the number of heartbeats in a 10 second interval and then multiplied that number by 6 to attain Beats/min; an initial (before treatment) HBR and after treatment HBR were recorded for each Daphnia Magna. The raw data were written down in a table and were later moved for demonstration on a graph for the final preview. The data collected matched the expectations, for the controlled group: the heart beat rate was dropping slightly (becoming slower), the reason behind that was most likely the cooling chamber because there was no treatment applied or any other external
622 Y. When the AV node receives the signal, it fires and causes the ventricles to depolarize, this is known as the QRS Complex. The atria also repolarizes during this phase. Specifically in the QRS Complex, during the Q wave, the interventricular septum depolarizes, during the R wave, the main mass of the ventricles depolarizes, and during the S wave, the base of the heart, apex, depolarizes. After the QRS Complex, the S-T segment can be identified as a plateau in myocardial action potentials and is when the ventricles actually contract and pump out blood to the pulmonary and systemic circuits. The final phase of the heartbeat is the T wave and this is when the ventricles repolarize before the relax, ventricular diastole, EKG Video Notes and pg. 671 D. These phases represent the cardiac cycle, which is the time and events that occur from the beginning of one heartbeat to the beginning of the next heartbeat. In this lab, the first EKG that I took was my regular heartbeat during rest. In this recording, I was able to see the P wave, followed by the QRS Complex and the T wave as well. Everything looks pretty normal, but the T wave does go a little lower than normal and I believe this is due to the fact that I was diagnosed with sinus bradycardia
The experiment studies the effects of Red Bull and its major components on the heart rate of a Daphnia. The experiment focuses on the effects of conditions on the cardiovascular system. The Cardiovascular system is responsible for the transport of blood, oxygen, nutrients and waste circulating the body. It consists of the heart, vessels, and blood as in closed circulatory system and hemolymph in open circulatory system, the cardiovascular system is also responsible for thermoregulation in the body. (Gonzalez, 2012). The heart helps pump blood to the lungs and rest of the body. The pumping of heart or the contraction and relaxation of heart determines the heart rate and depends on multiple chemicals that we could influence by using stimulants, depressants, varying temperatures, aerobic, and anaerobic
...dwin M, Parlow JL. Effects of low-intensity exercise conditioning on blood pressure, heart rate, and autonomic modulation of heart rate in men and women with hypertension. 2009 Oct; Vol. 11 (2), pp. 129-43. Date of Electronic Publication: 2009 Jan 15. Ebscohost. Available from: http://web.b.ebscohost.com.proxy.elmhurst.edu/ehost/detail?sid=e45c21d6-7074-4dc5-8390-f4e832d5c470%40sessionmgr110&vid=1&hid=126&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=mnh&AN=19150992
I predicted that the blackworms in higher caffeinated solutions would have higher pulse rates, because caffeine is known to increase blood pressure and heart rate. However as far as scientists know, invertebrates are not expected to have a strong response to caffeine like vertebrates do. Also, caffeine in low doses is known to lower pulse rate. The results do not support my hypothesis. The results show that when black worms are placed in caffeinated solutions, their pulse rates on average are lower than those placed in a solution with no caffeine. A possible flaw that may have occurred during experimentation is that the petri dishes were not properly cleansed, or that there were other properties in the water that influenced the outcome. To eliminate these flaws, I could have boiled the petri dishes and water to insure that there were no other properties to influence the data. Further experimentation should be performed with higher doses of caffeine to further insure that caffeine does in fact lower their pulse rate. The insufficient number of trials performed lead to less confidence in my conclusion that caffeine lowers the heart rate in
The second part of this lab was a computer simulation program to illustrate a frog’s electrocardiogram using various drugs in an isolated setting. The computer program entitled “Effects of Drugs on the Frog Heart” allowed experimental conditions to be set for specific drugs. The different drugs used were calcium, digitalis, pilocarpine, atropine, potassium, epinephrine, caffeine, and nicotine. Each of these drugs caused a different electrocardiogram and beats per minute reading. The calcium-magnesium ration affects “the permeability of the cell membrane”(Fox). When calcium is placed directly on the heart it results in three physiological functions. The force of the heart increases while the cardiac rate decreases. It also causes the appearance of “ectopic pacemakers in the ventricles, producing abnormal rhythms” (Fox). Digitalis’ affect on the heart is very similar to that of calcium. It inhibits the sodium-potassium pump activated by ATP that promotes the uptake of extracellular calcium by the heart. This in return strengthens myocardial contraction (Springhouse). Pilocarpine on the other hand
Sympathetic pathways change nerve activity during times of stress, exercise, low blood glucose levels, excitement or fear, due to the flight or fight response. These changes can have an effect on homeostasis by increasing heart rate, increasing blood flow, dilating pupils, sweating, releasing glycogen, increasing oxygen intake and diverting blood flow away from the gastrointestinal tract.
Nicotine works as both a depressant and a stimulant depending on the dosage. The experiment will be separated into 6 groups each testing a single substance at either high or low concentration. These groups will be recording several worms heart beats in order to prove each individual's personal hypothesizes on which solution will have the greatest effect and which substance with having the weakest effect. Due to the toxic nature of nicotine, it is hypothesized that nicotine at high concentration will have the greatest effect on the worms. It is hypothesized that the low concentration of caffeine will have the weakest effect. The goal of this experiment is to find which substance at which concentrate has the strongest and weakest effect to better understand homeostasis. This experiment also will provide insight into how these three substances affect living
When the subject submerged their face in 25 degree water, their heart rate decreased. It did not decrease very much because the water was at room temperature. It decreased more at 15 degrees and even more at 5 degrees. This was expected to happen because the diving reflex took place. The cold water puts the body is oxygen conserving mode and restricts the blood in your extremities. This is what reduces oxygen consumption which eventually lowers the heart
AIM: - the aim of this experiment is to find out what the effects of exercise are on the heart rate. And to record these results in various formats. VARIABLES: - * Type of exercise * Duration of exercise * Intensity of exercise * Stage of respiration
If it is a substance like a sleeping pill, aspirin, or others within this category will decrease the heart rate. Each of these effects has a mechanism of action, to explain; adrenalin also has another name and that is epinephrine. The action that it takes is that it is an alpha and a beta-adrenergic receptor, it reacts by causing the increase in vascular constriction and decreasing vasodilation (Inc.). Also, adrenalin is a hormone that is secreted in the body and involves the fight or flight response, decreasing heart rate, and increasing calcium channels to open. Nodal cells will reach threshold more quickly and will increase the firing rate of the SA node. The faster stimulation of the heart is by the delay in the AV nodes that causes a decrease. Next, is ACh acetylcholine its mechanism of action is that it works on decreasing the activity of adenylate cyclase by acting upon the muscarinic receptors (Callahan). ACh is also a neurotransmitter, which can bind to specific receptors. It is then used by nerve cells to control different things like, the heart, lungs, and muscles. ACh does this by releasing into the SA node, the action that it involves is that it decreases the rate of the SA node, by increasing the potassium and decreasing calcium and sodium movements. Also, Alka seltzers involves in inhibition of cyclooxygenase, aiding in the production of
The heart is a pump with four chambers made of their own special muscle called cardiac muscle. Its interwoven muscle fibers enable the heart to contract or squeeze together automatically (Colombo 7). It’s about the same size of a fist and weighs some where around two hundred fifty to three hundred fifty grams (Marieb 432). The size of the heart depends on a person’s height and size. The heart wall is enclosed in three layers: superficial epicardium, middle epicardium, and deep epicardium. It is then enclosed in a double-walled sac called the Pericardium. The terms Systole and Diastole refer respectively and literally to the contraction and relaxation periods of heart activity (Marieb 432). While the doctor is taking a patient’s blood pressure, he listens for the contractions and relaxations of the heart. He also listens for them to make sure that they are going in a single rhythm, to make sure that there are no arrhythmias or complications. The heart muscle does not depend on the nervous system. If the nervous s...
It was placed on a slide, a couple drops of water was placed on the slide to keep it moisturized. Next, we used a microscope to observe the heart beating in the transparent animal. According to the lab report on page 98 the normal heartbeats are about 350 per minute. By using a pencil and paper, we made a small dash for every heartbeat over a 15 second interval. Than we continued to repeat the observation of the heartbeats 3 more times for a total of 4 observations. We than totaled up the number of dashes and calculated the average of the four 15 second observations, this was labeled “Normal Heart Rate” on Table 1. Next we added 1 drop of an “unknown” solution that was assigned, we made sure to determine the average normal heart rate before doing do. The same procedure outlined above was conducted. The records were than placed in table 1. We than used water in replace of the unknown solution. The same procedure was conducted, we analyzed whether the Daphnia had recovered or not. Lastly our records were compared among our