Thursday, September 18, 2014

Homeostasis Lab


We did a lab that showed homeostasis taking place. There were many different changes that you could study to demonstrate homeostasis. The way my group picked was our heartbeat. We decided to swim and run. Remember homeostasis is  is the property of a system in which variables are regulated so that internal conditions remain stable and relatively constant.

Materials:

  • Heart rate monitor
  • swimming pool
  • stairs
  • pencil
  • paper




Procedure:

 On the first day we did swimming and I, Leah, swam a total of 5 laps. The first 3 laps my heart rate went up by 40%, at 4 laps it went up by 66%, and at 5 laps I was at 53%. Christian also swam and her results were: 3 laps a rise of 4%, 4 laps a rise of 18%, 5 laps a rise of 6%. The next day we both ran stairs. Here are Christians results: 2 stairs a rise of 38%, 4 stairs a rise of 17%, and 6 stairs a rise of 21%. Here are my results: 2 stairs a rise of 53%, 4 stairs a rise of 19%, and 6 stairs a rise of 45%. 


Conclusion:

Everytime we collected data, the second result always went down then the third went right back up. I think this is because after the first time our body was going to homeostasis and thats why the second result was less. When we did something the third time it went right back up, but not by to much. Down below are graphs of the data we collected.










Monday, September 8, 2014

Homeostasis

When it comes to our daily life, homeostasis is beyond important. Homeostasis is the ability for us to maintain relatively stable internal conditions even thought the outside world changes continuously. During homeostasis the internal environment of the body is in a dynamic state of equilibrium. All homeostatic control mechanisms have at least three interdependent components. The first one is the receptor. The job of this is it has a sensor that monitors the surrounding and reacts to the changes then sends the information to the second component, which is the control center. The control center determines the set point, analyzes the input it receives and then determines the appropriate response or course of action. The effector is the third component, which it provides the means for the control center's response to the stimulus. All the information flows from the control center to the effector along the efferent pathway. The outcome of the collected results then feed back to influence the stimulus. The feed back either depresses it causing the whole control mechanisms to shut down; this is also known as negative feed back. The feed back may also enhance it causing the reaction to continue at a faster rate, which is known as positive feedback.

The two ways your body can respond are by having a negative feed back or a positive feedback. Most control mechanisms are negative feedback. This means they go opposite in the way they are heading or the output shuts down what's going on reducing the intensity. Our body temperature changing is one of the many ways the nervous system maintains the constancy of the internal environment. There is a type of neural control mechanism that is seen in the withdrawal reflex, in which a hand is being jerked away from broken glass. The endocrine system is also important in maintaining homeostasis. An example of hormonal negative feedback is the control of blood glucose levels by pancreatic hormones. To continue regular metabolism, your body cells need a constant supply of glucose the produce cellular energy. For example if you have an intake of a lot of sugar, your blood sugar level shoots through the sky. The pancreas responds by secreting insulin into the blood.

                                           

The other way your body can respond is by having positive feedback. This is when the result of something causes the original stimulus to enhance that way the activity is accelerated. The change that occurs proceeds in the same direction as the initial disturbance, which pushes whats going on farther and farther from its rate. Positive feed back usually control infrequent events that do not require continuous adjustments. An example of positive feedback is labor contractions. The contraction become faster and faster until the baby is born. Oxytocin is what is being released that causes the contractions to continue. After the baby is born an event that ends the oxytocin is released and shuts off the positive feedback mechanism.
       
                               



Another example is when you get a cut and your body clots it. Down below is a picture explaining how it works.