Physiology Exercises

I received this message from the NSTA Listserv from Kevin in Texas

"The History Channel has a series on Tuesday nights called Evolve, 9:00 PM Central Time. This evening episode was Evolution of Eyes. They did an impressive job of presenting the mechanisms and interesting examples. Next week's episode will be evolution of the digestive tract. It is well worth the time investment to watch it. It appears the series can be ordered. If you want a synopsis, PZ Myers (a biologist and University Prof) live blog tonight's episode. 

http://scienceblogs.com/pharyngula/2008/07/evolve_eyes.php   

I did not watch the show as I was on the phone helping a friend prepare for an interview for a chemistry teaching position in a private NJ school. He is a Ph.D. leaving industry to enter the teaching profession. He has been tutoring high school chemistry, physics, and math for the last 18 months. The tutoring agency for which he works recommended him to the school. Our conversation took a long time as I attempted to acquaint him generally with the culture of private schools and life as a teacher. Much too much information for a two hour phone conversation but time enough to prepare him for the interview. He is the father of two Middle School aged boys, but has never been in a classroom setting as a teacher. I could not help but think how much he would learn spending one day at the Institute with us.

The little "flash" program that we used this morning on physiology is one of the most useful things I've been exposed to during this institute.  I can import this as is right into my lesson on barometers.  There is a bit of interactivity in the lesson I have now, but this gets the kids working interactively with the computer.  It can involve all the kids totally instead of just those whose attention I can keep for the whole process.

I'm still debating whether I should be having the kids do it at home and then having them write up a response . . . or whether we should move the class into one of the computers rooms so each student can have his/her own machine at the same time.  I don't trust bringing in the computer cart b/c every time I plan to use it, I find several of the machines are dead or the school district's wireless system "just went out."

There is no way that I am currently capable of preparing anything that complete in flash or Scratch or Alice or NetLogo.  Even better:  I don't have to.  It's already done.

What I find particularly good is that it is recursive and diagnostic.  It explains why the student's answer is right or wrong before moving to the next level.  That's a very necessary but rarely included feature in a lot of eduware.

The only item I can complain about is the theory given for the the slowing of flow due to the constriction placed on the pipe.  However, I can use that by telling the students that there is a misconception included in the program . . . and that I will give extra credit to the first team that finds and explains it.

And as for model building, this program allows me to have the students create a model and then illustrate to them immediately how a model can be extended to help them understand and absorb "new knowledge."

This morning was a feast of inquiry based activities. Each activity seemed to have endless extensions thanks to the guidance of Peter. Some activities, like the effect of position on heart rate, are already part of my Grade 7 biology class, but my organization of this activity will improve in the direction of becoming more open ended after this morning's discussion.

The Mass and Heart Flow software would enhance both levels of biology that I teach, but I think it will be most effective in AP Biology. At first, I thought how much it would contribute to the students' understanding of water potential as it relates to plants. Peter pointed out that the modeling would also contributed to a study of cardiac outflow and the effects of obesity and atherosclerosis. He sugested the example of snorkling and the increase in resistance due to dead space on the driving force.

Who said that science was fun? Double A+ to those people!!! The Grade 7 Biology students will love the exercise to lower heart rate by holding the breath followed by breathing from a bag filled with room air and testing breath holding again. The dive response- I am not sure of with Grade 7 but the older AP students would respond favorably to this exercise and would understand extentions into discussion of cold water marine animals and babies.

The reaction time trials with and without distractions is an activity I will use with the AP students. The extention into a discussion of driving and texting is an important connection for them to experience.

Thanks also to Alan for sharing his experience in physical therapy. I really never understood why the heart rate increases when changing from a sitting at rest to a standing position.

       There are several ways of incorporating physiology in the middle grades like my 4th grade classroom. There was a time we had the human body as part of the curriculum and there was a time we worked on our pulse rate etc. The interesting part of it is that students enjoy theses and will always learn as much as the activities allow them to, especially when it involves inquiry.

      The activity on reaction time will be a great one to teach the importance of paying attention or focussing. This will be very appropriate for safety lessons in social studies. As students practice, they will discover that they will get better. Just as Allan Bronstein mentioned, this will remind students that they should help spread the message that people should avoid using cell phones while driving.

I just had a reaction that sent chemicals into my brain and created a brief period of depression, after I accidentally deleted my blog entry. It's gone! But I am happy to say that the chemical reaction is dissipating and I am feeling better. Maybe I needed this to put PHYSIOLOGY into perspective!

Peter told us about Dive Reflex and it cleared up what I've always wondered how reptiles and some amphibians stay submerged under soil or mud for the winter months. In humans, the Dive Reflex allows mostly younger humans to stay alive when floating in freezing water. The body only uses oxygen in the blood to pump to the heart and brain, so we don't have to breathe as much as we would normally.

What is the difference between reflex and reaction:

Many people conider only the simplest types of responses as "reflexes", those that are always identical and do not allow conscious actions. We must not confuse these with "reactions", which are different from reflexes in that they are voluntary responses to a stimulus from the environment. For example, while the body has various subconscious physiological responses to mitigate cold, as humans we can simply choose to put on more clothes. This is a conscious order made by the cerebrum, not an involuntary response to a stimulus. This is a very complex response involving millions of neurons and some time to process the voluntary response. In contrast, spinal reflexes occur much faster, not only because they involve fewer neurons, but also becuase the electrical signal does not have to travel to the brain and back. Spinal reflexes only travel to the spinal cord and back which is a much shorter distance. Because of this and the complexity of conscious reactions, they take more time to complete than a reflex. On average, humans have a reaction time of 0.25 seconds to a visual stimulus, 0.17 for an audio stimulus, and 0.15 seconds for a touch stimulus (2). Reaction times vary from individual to individual. Because of the higher degree of neural processing, reaction times can be influenced by a variety of factors. Reaction times can decrease with practice, as often times athletes have faster reaction times than non-athletes. Sleepiness, emotional distress, or consumption of alcohol can also impact reaction time.