The Nervous System and Its FunctionKASI SCHROEDERALEXIS ARIAS

Central Nervous System (CNS)

Made up of the brain and spinal cord.

Processes and responds to all messages coming for the peripheral nervous system.

The Spinal Cord: An Extension of the Brain

The Basis of the Nervous System: Axons

Axon Connections

Synapses are what Connect Motor Neurons

How are Motor Neurons/Axons Different Than Normal Cells?

There is one key difference between neurons and other cells. Neurons are specialized to transmit information throughout the body.

Action Potentials

Its what sends the electrical signal from one neuron to another neuron. Cell membrane

Resting Membrane Potential(mV) is approximately -60mV Must become more positive in order to fire a signal (action potential)

Information Collection

Some neurons are sensory neurons

These neurons gather information about what is happening in and around your body. They have special nerve endings called receptors.

Example: receptors in your eyes detect light and then send the information to the CNS for processing!

Sensory Nerve Cells (Neurons)

• Activated by mechanic stress, temperature changes, and acidity changes.– Mechanoreceptors, Thermoreceptors, pH receptors

• Have graded potentials.

Citations for PicturesAxon) https://www.google.com/search?q=axon&espv=2&biw=1048&bih=1041&source=lnms&tbm=isch&sa=X&ei=J6Y2VZjqHuq0sAT-r4Fo&ved=0CAYQ_AUoAQ&dpr=0.9#imgrc=nzDhTZ9pYUmBXM%253A%3BSrmiNWGT9pB-jM%3Bhttp%253A%252F%252Fimg.docstoccdn.com%252Fthumb%252Forig%252F80653935.png%3Bhttp%253A%252F%252Fpixshark.com%252Faxons-and-dendrites.htm%3B1650%3B1275Axon Connection) https://www.google.com/search?q=axon&espv=2&biw=1048&bih=1041&source=lnms&tbm=isch&sa=X&ei=J6Y2VZjqHuq0sAT-r4Fo&ved=0CAYQ_AUoAQ&dpr=0.9#imgrc=nzDhTZ9pYUmBXM%253A%3BSrmiNWGT9pB-jM%3Bhttp%253A%252F%252Fimg.docstoccdn.com%252Fthumb%252Forig%252F80653935.png%3Bhttp%253A%252F%252Fpixshark.com%252Faxons-and-dendrites.htm%3B1650%3B1275Synapse) https://www.google.com/search?q=axon&espv=2&biw=1048&bih=1041&source=lnms&tbm=isch&sa=X&ei=J6Y2VZjqHuq0sAT-r4Fo&ved=0CAYQ_AUoAQ&dpr=0.9#tbm=isch&q=synapse&imgrc=VnyE9ZI72AeZtM%253A%3BA7fM8NAgxUbbIM%3Bhttp%253A%252F%252Fthumbs.dreamstime.com%252Fz%252Fsynapse-28463798.jpg%3Bhttp%253A%252F%252Fwww.dreamstime.com%252Fstock-images-structure-typical-chemical-synapse-neurotransmitter-release-mechanisms-neurotransmitters-packaged-synaptic-vesicles-image35155754%3B1300%3B1065Brain) https://www.google.com/search?q=labeled+human+brain&es_sm=93&tbm=isch&imgil=fxHYZvhr4Yy_kM%253A%253BCcnNwEW6SibKlM%253Bhttp%25253A%25252F%25252Freal-i-d.net%25252Flabeled-human-brain.html&source=iu&pf=m&fir=fxHYZvhr4Yy_kM%253A%252CCcnNwEW6SibKlM%252C_&usg=__Aljuft6IU6c-bqjzkctF9lH_peE%3D&biw=1048&bih=1041&dpr=0.9&ved=0CCgQyjc&ei=MaU2VeGhD6rksAS9voCIDg#imgrc=O4DktwvmpIxxXM%253A%3BSjCzPn_PC2iMqM%3Bhttp%253A%252F%252Fwww.paulkiritsis.net%252Fimg%252Fuploads%252F2012%252F10%252Fbrainparts12.jpg%3Bhttp%253A%252F%252Fourteam.biz%252Ftag%252Flabeled-diagrams-of-the-human-brain%3B2175%3B1400Spinal Cord) https://www.google.com/search?q=spinal+cord&es_sm=93&source=lnms&tbm=isch&sa=X&ei=R6Y2VYnXMqzisASn7IEY&ved=0CAcQ_AUoAQ&biw=1048&bih=1041&dpr=0.9#imgrc=dfwYDWdWq4OgJM%253A%3B-uFANbqbnuKfrM%3Bhttp%253A%252F%252Fwww.sci-recovery.org%252Fimages%252Fvertebraeandspinalcord.jpg%3Bhttp%253A%252F%252Fwww.sci-recovery.org%252Fsci.htm%3B400%3B320

Lab Activities

Spiker Boxes w/ EMG: Correlation between contraction force and rate of firing seen on the phone screen. Experiments-

Changing contraction force Angle of Contraction Contraction Rate

Cockroach Legs: Different areas of sensitivity Experiments-

Pressure Changes Length of Stimulation Whisking against leg sensory hairs

Results

The students already knew a lot about the nervous system and motor neurons. We were able to reinforce and put the information into tangible

experiments that helped reinforce what they had learned prior to, and during our presentation.

The students were very engaged. Several students raised their hands to answer each question that we asked during the presentation. Their attentiveness and comprehension during the experimentation

portion of our presentation showed that they did in fact learn more about action potentials in particular.

Results continued…

Questions Asked: How do action potentials begin? – receptors in the membranes of

sensory cells allow ion flow and positive change in membrane potential.

How many times can a motor neuron fire an action potential? – as long as ions are available action potentials can occur.

Why do you still get burned if you pull your hand off the stove right away? – it takes time to not only sense the heat, but also to travel along motor neurons and back to the hand to pull the hand away.

Feedback

We got really good feedback from the students who said they had a better understanding of the nervous system and action potentials because of the experiments.

We received an email from the teacher thanking us for coming in and presenting and providing a hands-on experience for the students to learn more about topics they had covered previously in class.

Suggestions for Improvement

Make sure you know that the cord connecting the EMG box to the phone is connected correctly – not a normal auxiliary cord.

We knew they had previously covered some of this material, so we recommend making sure there is an understanding of how advanced the students are in the topic. This would have helped us in that we could have went more in-depth than we did during our presentation.