389251809-experiment-2.docx

EXPERIMENT 2 : GASES EXCHANGE IN ANIMALS

OBJECTIVE : 1. To relate the effect of various factors on the human pulse rate.

MATERIALS : 1. Stopwatch 2. Stethoscope 3. Stool, 45 cm high 4. Facilities for taking vigorous exercise, e.g. running track or field for performing 100 metre sprint

PROCEDURE : A. Effect of Posture on The Pulse Rate

1. The subject was laid down quietly for five (5) minutes after which his or her pulse rate was determined. 2. The subject then was standing up for a further three (3) minutes after which the pulse rate has be taken. The differences between the two readings was explained in discussion.

B. Effect of Hyperventilation on Pulse Rate 1. The continuous readings of the subject’s pulse was obtained over a period of seven (7) minutes. The number of pulses were counted by every fifteen (15) minutes and converted to per minute afterwards. 2. The subject was seated and relaxed and the partner took the subject’s pulse rate continuously for two (2) minutes. 3. The subject was engaged in forced deep breathing for 30 seconds; as deeply and frequently as possible, but with the minimum of muscular effort to the body as a whole. 4. The subject was breathed normally for a further five (5) minutes during which the partner was recorded his pulse rate every fifteen (15) seconds. Was the pulse rate fell below normal at any point ? It was explained in discussion.

C. Effect of Exercise on Pulse Rate

1. The standing rate was converted from x/60s to x/10s before proceeding to this step. 2. The subject was engaged in a standard bout of exercise as follows : step onto a stool of 45 cm high ( was changed to stair) and then down again, once every three (3) seconds, thus taking (15) seconds in all. 3. The partner was measured the subject’s pulse rate at 10 seconds intervals immediately after the exercise until it returns to the normal standing rate. 4. A graph of the results was plotted, the pulse rate on the vertical axis and the time on the horizontal axis. 5. The experiment C was repeated with a much heavier bout of exercise by performing a 100-metre sprint. The result was compared with the previous exercise.

RESULT : Table 1 : Pulse Rate in Difference Conditions Trial (pulse rate / minute)

A

B

C

Lying down

Standing

Average

1st

2nd

3rd

74

72

74

73.33

79

77

71

75.67

rate

Exercise

Pulse rate / 10s (x/10s from x/60s)

= 13/10s

1st - Light

Total

10s

20s

30s

40s

50s

60s

70s

17

16

16

15

15

14

13

106

2nd - Vigorous 10s

20s

30s

40s

50s

60s

70s

27

21

20

19

17

14

13

131

DISCUSSION : From this experiment, we identified that every human pulse rate were different with different kind of activities. Heart rate is the measurement of the number of times your heart contracts or beats in one minute. Heart rate changes based on the position of the body. Everyone has the same oxygen consumption at rest per given body weight. However, as an individual moves from a resting state to one of exercise, the body demands more oxygen for metabolic processes to keep up with the energy demands. Naturally, as the body moves from rest to exercise, the heart rate begins to steadily increase. This cardiovascular response allows for faster oxygen delivery to the working tissue, such as skeletal muscle, which allows for an increase in oxygen consumption. It was shown that our body position can influence the number of times your heart beats per minute. When the subject was lying down, the pulse rate are fewer than when you are sitting or standing. When you are lying down, the effect of gravity on your body is reduced which allowing more blood to flow back to your heart through your veins. Because more blood returns to the heart, the body is able to pump more blood per beat, which means that less beats per minute are required to satisfy your body's demand for blood and oxygen. Then the pulse rate will become higher when the subject are moving from lying to sitting then to standing position. A resting heart rate averages between 60 and 80 beats per minute.The more vigorous exercise you are doing, the more higher your pulse rate is. When you are doing exercise, the muscles use the oxygen to generate the energy. Your heart pumps blood to the muscles and body tissues, delivering the oxygen needed to keep them functioning. The muscles demand for oxygen increases sharply when doing the exercise. The higher demand for oxygen stimulates a rise in heart rate, which increases the amount of oxygen-rich blood delivered to your muscles.

CONCLUSION : In this experiment, it can be concluded that different kinds of postures, how are you breathing, and intensity of exercise will affect the human pulse rate. The human pulse rate is increasing when you are standing and doing vigorous exercise. The fitness of the subject is good.

POST LAB QUESTIONS AND ANSWERS : 1. What are the factors might cause a person’s a pulse rate to increase ? -

The factors might cause a person’s a pulse rate to increase including fitness level, altitude, body positions, body size, air temperature and emotional level.

2. Why do pulse rates increase during exercise ? -

As we begin the exercise, the heart rate will become increase as the muscle demands oxygen to generate energy. 1n order to continue making more energy, the muscles require additional oxygen pumped from your heart thus will cause your heart to pump faster.

3. Do you think this is a valid way of assessing a person’s fitness ? Can you suggest a better method ? -

Yes, it is a valid way to assess a person’s fitness because by measuring heart pulse rate by doing various exercises we can determine how healthy and fit a person is. A better method that you can use is by playing pick up game. Play any game in such 20-30 minutes like ultimate Frisbee, basketball or soccer.

4. How would you account for your results in terms of your particular lifestyle (i.e. do you take regular exercise, do you smoke etc?) -

I could obtain a good result as every evening I will spend one hour to jog and even consume a balanced diet routine.

5. What conclusion can you draw from your results ? -

We should practise a healthy lifestyle such as doing regular exercise and consume nutritional foods to get a better result in assessing your fitness.

REFERENCES : 1. Campbell, Reece, Urry, Cain, Wasserman, Minorsky, Jackson (2015). Biology, 10th Edition, Pearson Education, England. 2. Solomon, E.P., Berg, L.R. & Martin, D.W. (2011). Biology. 9th Edition. Australia. Saunders Collage Publishing. 3. Enger, Eldon D. and Ross, Frederick C, Concepts in Biology, 10th Edition, Mc Grawhill, 2003. 4. Gan Wan Yeat, Success Biology SPM, 2013, Oxford Fajar Sdn. Bhd. 5. https://www.livestrong.com/article/137631-what-factors-can-influence-heart-rate/