The objective of the experiment:The objective is “To investigate aspects of the control of salivary secretion and the location and function of the taste receptors in the mouth”.MethodologyFor the experiment of salivary secretion in the human subject, we worked in groups of 6, for this experiment, the person who carried out the salivary secretion was a 18 year old female.The second experiment was the taste experiment, we stayed in the same groups, and a 18 year old male carried it out.In the salivary experiment the female volunteer tilt her head forward, then she swallowed her sliver before we timed the experiment, this stopped them from swallowing during the experiment as well as allowing them to keep their tongue and jaw still during the experiment, as it is timed. We did these 3 times, and each of the periods was timed for 2 minutes. The sliver after the 2 minutes was spat into a beaker, the beaker allowed us to measure the amount of sliver produced, this then allowed us to calculate the resting rate when the sliver was collected.
After the salivary secretion, we did the stimulated secretion, this was to place 1 ml distilled water under the tongue, and then vigour sly chew, spitting out saliva into a beaker for 4 minutes. This then was measured, as this measurement allowed us to calculate the flow rate of salivary.Next was the acid substances, in this experiment we had to place a small crystal acid on the tongue, then performed the steps in the stimulated secretion to see whether the acid slowed down or speeded up the flow rate of saliva.We then as a group did exercise to see the effect on secretion, the female volunteer, rinsed her mouth with water to remove any traces of acid. Before the exercise he had to swallow, and then the experiment lasted for 2 minutes, where he had to vigorously run on a spot. After 2 minutes the saliva was measured in a beaker, and then the experiment was performed again. We then measured the saliva collected and compared it with the saliva measured at resting rate.
Finally we did the taste experiment, this involved 11 different types of solutions, these were placed in the moth using pipettes, and also distilled water was used. This experiment was to find out whether the person could taste the solution and decide whether it is salty, bitter, sweet or sour.ResultsExperiment A: Saliva TestTable 1: My group’s results (Group 8)ConditionTotal volume of Saliva (ml)Period of time saliva was collected (min)Salivary Secretion Rate (ml/hour)Resting4.0640Chewing7.04105Acid Substances6.0490Effect of Exercise0.446The secretion rate of saliva was calculated using a formula, the formula is very simple and understandable, as the total volume of saliva which is in Ml (which was collected, multiplied by 60 and then divided by the amount of time in Min units.
The results obtained from the experiment show me that the most amount of saliva secreted was the chewing experiment. The amount of saliva, obtained after the acidic stimulation was greater than the resting rate of saliva. Overall the results show that the chewing has a greater effect to increase salivary secretion than any other way, such as by Acidic or exercising.In the results, the lowest amount of saliva collected was after the volunteer had finished their vigorous exercise, which was running on the same spot; this was done for 2 minute twice.
To get more accurate data the whole class shared there results. From these results it will allow me to see what the average rate amongst everyone is.Table 2: The class DataConditionGroupRestingChewingAcid SubstancesEffect of Exercise220.127.116.11.
61.0As I previously calculated the saliva secretion rate, I used the same formula to work out the average for the whole class.Table 3: Class data, (Calculated using formula) for Salivary Secretion Rate mlDifferent ConditionsGroupRestingChewingAcid SubstancesEffect of Exercise1135493182304254363152131.
561842.03915720631173084010590692516.5100.519.51026335415Since I have the results, to get an average answer, I worked out the mean and the standard deviation; I used Microsoft Excel to calculate both of them as it allows me to use formulas.Table 4: Class Data (Averages) Calculated using Microsoft ExcelConditionSalivary Secretion Rate (ml/hour)Standard Deviation (ml/hour)Extreme valuesResting21.
78.9;3.9 or ;39.5Chewing41.927.1;96.
6 or ;128Effect of Exercise22.313.7;49.7The extreme values are shown below, as the table shows that group 5 has similar results that match other group’s results. The similarities are there salivary rate increasing after chewing and consuming acidic flavourings.
However, my group (8) have different values to the other groups, this could be that due to the fact that our volunteer had a saw throat and a dry cough.Table 5: Extreme Data Values for Table 3GroupConditionSalivary Secretion Rate (ml/hour)5Effect of Exercise52.58Resting408Chewing105Overall the results show that the highest mean salivary secretion rate was after the tongue was exposed to an acidic solution. This was also the result obtained by most individual groups, however group 6 and group our group 8 were different.
Group 8 was our group, as well as group 6 we found that chewing had more salivary secretion rate than the others.From the class results it shows me that the resting rate was the most stimuli on average. The other groups such as 4, 6, and 10 found that the effect of exercise resulted in the least amount of secretion.Salivary Secretion RateSaliva is the watery substance produced in the mouth of some animals, on the other hands it is produced by all humans. Saliva is produced in salivary glands, the saliva is 98% water, but it contains many important substances, including electrolytes, mucus, antibacterial compounds and various enzymes.The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starches down into maltose and dextrin. This, digestion of food occurs within the mouth, even before food reaches the stomach.
The acid substance, which was the citric crystals created the highest secretion rate, this is because when an acidic or sour substance enters the mouth; a larger proportion of the volume is thin saliva, which is secreted, containing less amylase in order to dilute the stimulating substance resulting in the acidic taste.. This is known to make the substance less irritant.As we chew, this increases the rate of secretion, this is because when food enters the mouth the taste buds are stimulated, and these produce a secretion of saliva which contains amylase and mucus. As we chew more, the amount of amylase is increased which enables the first part of digestion to occur in the mouth.When we did the experiment which involved doing exercise, as you do exercise, there is less blood which reaches the moth gland which secrete saliva, the decrease of blood is due to the fact that the blood is taken to the muscles as they need the oxygen and energy to contract, the decrease in the blood to the mouth makes the mouth dry.By looking at the class results, 6 out of the 10 groups found that the resting rate was the lowest secretion rate obtained throughout the whole experiment.TasteBelow is a table to show the results for the 11 different solutions tasted by the male:SolutionTasteComposition1No TasteTap Water2Salty2% NaCl3Bitter2% KCl4Bitter8% MgSO4.
H2O5Very Bitter0.01% Quinine Sulphate6No TasteTap Water7Sweet5% Sucrose8Sweet5% Glucose9SourLemon Juice10Sweet and SourLemon Juice in 5% Sucrose11No TastePhenylthioureaThe table below shows the results for my group:Solution1234567891011TasteNoneSaltyBitterBitterSourNoneSweetSweetSourBitter-SweetNoneWith all the experiments we carried out, the height, weight, age or gender of the person was not controlled, therefore I cannot say to an extent if the outcome would have been affected by these factors.The tongue is a large skeletal muscle, on average; the adult has 9000 taste buds on the tongue. The tongue is covered in little bumpy lumps call papillae, there are 3 types of papillae, and these are:* Filiform* Fungi form* Circumvallates”The human tongue can detect five basic taste components, sweet, sour, salty, bitter and umami. The sense of taste is referred to as a gustatory sense; there are no distinct regions for tasting different tastes’. (Taken from http://en.
wikipedia.org/wiki/Tongue)The diagram below shows the different types of glands:Taken from: http://health.enotes.com/images/cancer/gec_02_img0183.
jpgThe last solution was Phenylthiourea, and this can only be tasted by a few people. The people that can taste this are because of a genetic inheritance. In my group the male could not taste the solution, therefore it resembled that he did not genetically inheritance.GraphsThe line graph below shows the secretion rate for all the groups, I have calculated the average amount of saliva for 1 hour; this is the data from table 3:The bar chart below shows the Standard deviation that I worked out for the whole class using Microsoft Excel, and the average secretion rate for 1 hour.
The data is taken from table 4: