TEKS 10 A & B, 11C Nervous System TAKS Objective 2 – The student will demonstrate an understanding of living systems and the environment. TEKS Science Concepts 10 A & B The student knows that, at all level of nature, living systems are found within other living systems, each with its own boundary and limits. The student is expected to: (A) interpret the functions of systems in organisms including circulatory, digestive, nervous, endocrine, reproductive, integumentary, skeletal, respiratory, muscular, excretory, and immune; (B) compare the interrelationships of organ systems to each other and to the body as a whole; 11 C The student knows that organisms maintain homeostasis. The student is expected to: (C) analyze the importance of nutrition, environmental conditions, and physical exercise on health TAKS Objective 2 page 1 BIOLOGY For Teacher’s Eyes Only Teacher Background: There are twelve major organ systems in the human body (i.e., circulatory, skeletal, respiratory, excretory, integumentary, nervous, digestive, endocrine, reproductive, immune, lymphatic, and muscular systems). In this TEKS, we will introduce students to the common structures of each system and their basic functions. A brief description of these systems follows: Nervous System – The nervous system is interrelated with all other systems. It controls, regulates and communicates with all the other body systems. The nervous system is also the hub of all mental activity including memory, thought, and learning. The nervous system consists of the brain, spinal cord, nerves, and neurons. These organs work together with the organs of the endocrine system to collect information about the external environment and determine how it relates to the body’s internal state. The nervous system then compiles this information and initiates the body’s response to maintain homeostasis. The nervous system is broken into two separate systems, the Central Nervous System and the Peripheral Nervous System. The central nervous system (CNS) consists of the brain and spinal cord, while the peripheral nervous system (PNS) includes all the nerves that collect information about the external and internal environment to be quickly interpreted by the spinal cord. Beating of the heart and digestion of food is under the control of the peripheral nervous system, which is responsible for unconscious body functions. However, the PNS can be further subcategorized into the Sympathetic and Parasympathetic Systems. These two systems keep each other in check by working in opposing action to one another. Student Prior Knowledge Students should be familiar with the components associated with body systems TEKS 6.10 (C) identify how structure complements function at different levels of organization including organs, organ systems, organisms, and populations and the functions of these systems. TAKS Objective 2 page 2 BIOLOGY Neurons and Nerves 5 E’s ENGAGE Lorenzo’s Oil Discuss the film guide and review the nervous system concepts that were covered in this film EXPLORE Exploration 1 Quick Communication UNC-CH Brain Explorer Students will be introduced to neurotransmission in the context of a reaction time experiment that demonstrates the concept of gravity and the reaction of the nervous system. Part I Set-up: -A book -Paper -Ruler -Reaction Time poster -Dry erase marker -Student Worksheet “Reaction Time Part I” PROCEDURE Bring out a ruler and ask a student volunteer to come up to the front of the class. Instruct the student to catch the ruler as it is dropped. • After the ruler is caught, ask student: "Why was the ruler caught in the middle (after a lag period) rather than at the end (instantaneously)? TAKS Objective 2 page 3 BIOLOGY "What causes this hesitation?" “What had to happen in my body for me to catch the ruler?” • Have students predict the sequence of events involved in the reaction time pathway. • Ask students what had to happen for you to grab the ruler after it dropped. • Demonstrate visually the process using the REACTION TIME POSTER. Use the dry erase marker to draw the reaction pathway: The eye sees the ruler drop. The eye sends a message to the visual cortex. The visual cortex sends a message to the motor cortex. The motor cortex sends a message to the spinal cord. The spinal cord sends a message to the hand/finger muscle. The finger muscle contracts to catch the ruler. • Distribute the worksheet and have students complete the top portion by writing the 5 key words from the word box in the correct order. • Have students complete the lower portion of the worksheet. They must write a short paragraph detailing the reaction sequence listed above (there are 6 components). Part II Set-up: -Distance/Time chart -Rulers (class set) -Reaction Time poster -Dry erase marker -Student Worksheet “Reaction Time Part II” After students have completed their reaction sequence paragraph perform the following: • Ask students, "What is speed and how do we measure it?" • Think of the speed that you drive a car. "What two units of measurement are used to describe the rate of a moving car?" Speed has two components: distance and time (miles/hour). • Show the students the ruler once again, and ask them, "How can we use this ruler to measure our reaction time?" Students should recognize that we have a distance component, but not a time component. • Students should hypothesize methods for measuring time. Ideally, one student will suggest using a stopwatch. • Have two student volunteers come to the front of the class. One student will catch the ruler as the teacher drops it, while the other student measures the reaction time. This demonstrates that our reaction times are less than a second, which is too short to be measured with a clock, watch, or stopwatch. Though this method for measuring reaction time is theoretically possible, it is simply too difficult to measure our reaction times manually. • Introduce students to the distance time chart created by scientists. TAKS Objective 2 page 4 BIOLOGY Discuss that we will be using this chart instead of calculating reaction times ourselves. We are able to use this chart since we know that all objects fall at the same rate in the absence of wind resistance (Galileo's Law). • Discuss the use of milliseconds on the distance time chart. Ask students how many milliseconds are in one second. Ask students to brainstorm what they can react to in less than a second. Ex: pulling a hand quickly away from a hot object. • Review technique/methods for measuring ruler catch distances. Stress the importance of standardization. • Students should round up to the first whole number above their finger/thumb every time they take a measurement. Also, students should keep the same distance between their finger and thumb and the ruler each time they take a measurement. • Review the distance time chart and how to calculate reaction times. • Distribute the reaction time worksheets and complete the top portion on recording data with the students. • Before beginning the experiment, students make predictions regarding which hand will be better at catching the ruler (faster). Teachers can use this opportunity to reinforce prediction/hypothesis formation. “How is a prediction different from a guess?” • Students work in pairs to practice catching the ruler and determining their reaction times. • Explain to students that they will each have the opportunity to catch the ruler 3 times (each hand). Then they will record the 4th catch distance and reaction time for each hand. They will record these measurements on their worksheet as their official reaction times. * If students are able, the three trial catch distances can be averaged to determine a more accurate estimate of reaction time. This is a good opportunity to introduce averaging if this topic is new to students. • Distribute rulers and begin experiment. • Students conclude by reflecting on whether their prediction was correct or incorrect and why. • Volunteer students can share their experiment results with the class. • Teacher and students discuss differences between left and right hands. "Why do you think one is faster than the other?" (Greater practice and use of one hand.) "Did you get faster at catching?" "Do you think we can improve our reaction times with practice?" • Discuss reasons why the students’ time might not have improved, like they were too excited or nervous to concentrate. • Students complete a handout describing the reaction process and put steps in sequence. • See if any students are able to narrate the reaction time sequence. On-line Extension • The Neuroscience for Kids website has on-line reaction time experiments that would be a great supplement to this lesson (particularly for students who finish early). • Go to http://faculty.washington.edu/chudler/chreflex.html and scroll down to the “How Fast Are You?” section for 3 different on-line reaction time experiments. TAKS Objective 2 page 5 BIOLOGY Exploration 2 Beady Neurons EXPLAIN Complete the Nervous System PowerPoint presentation with discussion and then divide students into teams to explain and answer questions while playing neuro-jeopardy. See neuro-jeopardy power point. Students should be capable of answering questions like the ones that follow: ELABORATE Neurotransmission: Nifty Neurons and Muscle Messages Modified from UNC-CH Brain Explorers Materials: • Reaction Time poster • Neuron Structure poster • White 8 x 11 paper • Class set of pastels • Small soft ball Reaction Time Review Review the engage activity reaction time experiment, using the ball and throwing it from one student to another for each step. The teacher can start the process; throw the ball to a student who identifies the next step. The ball is thrown to successive students until all the steps have been reviewed. 1. The eye sees the ruler drop. 2. The eye sends a message to the visual cortex. 3. The visual cortex sends a message to the motor cortex. 4. The neuron in the motor cortex sends a message to the neuron in the spinal cord. 5. The neuron in the spinal cord sends a message to the muscle cells in the hand. 6. The muscles in your hand contract to catch the ruler. TAKS Objective 2 page 6 BIOLOGY Nerve Cell Review • Ask students, "How are messages sent from place to place?" (i.e., eye to visual cortex, or visual cortex to motor cortex). Encourage students to consider the role of neurons in this process. • During the discussion, reveal facts about neurons such as the ones below. - Neurons carry messages in our bodies. - There are neurons that connect each point in the reaction time pathway. - Neurons are the building blocks of our nervous system. - The human brain contains about 100 billion neurons, each of which communicates with thousands of other nerve cells that together, control our every perception and movement. - Neurons allow us to breathe, move, feel, learn, remember, etc. • Ask students to recall what they learned about the structure of a neuron. Have students brainstorm the neuron terms that they know and write them on the board. • Hopefully students will remember that a neuron/nerve cell has several parts: dendrites, axon, cell body, nucleus, axon terminal, neurotransmitters, neurotransmitter, and receptors. • Use the neuron structure poster to review and discuss neuron structure. Nerve Cell Drawing • Students draw and label neurons using white paper and pastels. • Remind students that an important job of scientists is to record what they have learned. Sometimes scientists do this by creating a drawing or sketch. Like a scientist, the students are recording what they know about neurons, and it is important to be as accurate as possible. TAKS Objective 2 page 7 BIOLOGY Differences in Nerve Cells • Ask students, “Why might some nerve cells have different numbers of dendrites than others?” • Students may discuss their hypotheses. Reveal that younger brains (0 to 2yrs) have fewer dendrites than adolescent or adult brains because as you learn and use new thought processes, you require more dendrites and connections between cells. • In the artwork extension, students use Scratch LightTM paper to depict the increasing complexity of neurons as a child grows. EVALUATE 1. Using notes and text, students will compete to answer questions over the nervous system by playing Neurojeopardy. 2. After constructing a clay brain model, students will verbally identify 6 of 7 brain structures. 3. Students will construct a neuron model with 100% accuracy that contains dendrites, a cell body (soma), axon, and axon terminals. TAKS Objective 2 page 8 BIOLOGY TAKS Objective 2 page 9 BIOLOGY Film Guide for Lorenzo's Oil Please read these questions over before you see the film!!! 1. Show how Lorenzo's parents used the scientific method to solve their problem. State the problem, ask a question and use examples from the film to illustrate the steps. 2. From the description of the disease, ALD, sketch what Lorenzo's neurons most likely looked like after a year. Include a sketch of a normal neuron. 3. ALD is a recessive sex-linked or X-linked disease. What are the probable genotypes of the family members listed? Aunt #1_______ Augusto_______ Aunt Dee_______ Aunt #2_______ Lorenzo_______ Michalla_______ TAKS Objective 2 page 10 BIOLOGY 4. What is Lorenzo's Oil? How does it work? Use the sink model from the film. 5. Explain Augusto's use of paper clips to represent good and bad fatty acids. What did his dream help him understand? 6. Why did the medical community resist the Odones' treatment ideas? Why did the parent support group resist? Give examples of arguments for and against. 7. How do analogies help you to understand the scientific problem? How did modeling help solve the scientific problem? Can you think of other great discoveries that employed the use of models? TAKS Objective 2 page 11 BIOLOGY 8. How did Augusto and Michalla demonstrate "life-long" learning? 9. Defend the position that diseases that affect a small % of the population should not get as much money for research as the big killers like cancer and heart disease. 10. What was found out from the Polish biochemist? What was the purpose of the ALD Symposiums? What happens when scientists work in isolation? 11. What is erucic acid? 12. Where was the myelin research being done? What was the experiment? How could this research help Lorenzo? TAKS Objective 2 page 12 BIOLOGY Neuron Models 1. You should have four different colors of modeling clay or playdough. You are to build a model of a nerve cell using different colored clay for the various parts of the neuron. Remember the neuron has four basic parts. 2. Once you have finished your model, place your neuron in the box below. 3. Label and draw arrows to the following: 1. 2. 3. 4. 5. Dendrites Soma or Cell Body Axon Axon terminal Draw an arrow to indicate the path that an impulse will travel on your neuron TAKS Objective 2 page 13 BIOLOGY TAKS Objective 2 page 14 BIOLOGY Name: _____________ Date: ______________ Brain Explorers Reaction Time Part I Student Worksheet Word Box Visual Cortex Muscle Spinal Cord Motor Cortex Eye The words in the word box name the parts of your body involved in creating a response (ex. catching a falling object). Put the words in order according to how they are used in the body. 1. _______________________________ 2. _______________________________ 3. _______________________________ 4. _______________________________ 5. _______________________________ Now use these words, in the proper sequence, to write a paragraph describing the process that allowed you to catch the ruler. ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ ______________________________________ TAKS Objective 2 page 15 BIOLOGY Brain Explorers Reaction Time Part I Teacher Key The words in the word box name the parts of your body involved in creating a response (ex. catching a falling object). Put the words in order according to how they are used in the body. 1. Eye 2. Visual Cortex 3. Motor Cortex 4. Spinal Cord 5. Muscle Now use these words, in the proper sequence, to write a paragraph describing the process that allowed you to catch the ruler. First, your eye sees the ruler. Then, your eye sends a message to the visual cortex, which sends a message to the motor cortex. The motor cortex sends a message to the spinal cord. The spinal cord sends a message to the muscles in your hand/fingers. Finally, your muscles contract to allow you to catch the ruler. *Student responses may vary, but they must include the major components of the neural process. TAKS Objective 2 page 16 BIOLOGY Neurotransmission: Nifty Neurons TAKS Objective 2 page 17 BIOLOGY Brain Explorers Nerve Cell Drawing—Teacher Guide The following neuron structures should be included: Cell body with dendrites • Nucleus • Axon • Axon terminal • Muscle cell (optional) The following labels should correspond to the neuron drawing: • Neuron or nerve cell • Cell body • Dendrites • Nucleus • Axon • Axon terminal • Muscle cell (optional) TAKS Objective 2 page 18 BIOLOGY TAKS Objective 2 page 19 BIOLOGY Distance and Time Chart Reaction Time Catch Distance (in centimeters) Seconds Milliseconds 5 .100 100 6 .107 107 7 .114 114 8 .121 121 9 .128 128 10 .135 135 11 .142 142 12 .149 149 13 .156 156 14 .163 163 15 .170 170 16 .177 177 17 .184 184 18 .191 191 TAKS Objective 2 page 20 BIOLOGY Name: _______________________ Date: _______________________ Brain Explorers Reaction Time Experiment Record Sheet Things to remember when measuring your catch distances on your ruler: Start with the “0 cm” end of the ruler at the bottom, & have your partner hold the ruler just above your fingers. After you catch the ruler, record the number right above your thumb. What number would you record for this “catch distance”? a) 14 cm b) 15 cm c) 16 cm Example: Which ruler “catch distance” would you record? a) 7 cm b) 8 cm c) 9 cm If your catch distance is 13 cm, what is your reaction time? a) 144 milliseconds b) 177 milliseconds c) 156 milliseconds TAKS Objective 2 page 21 BIOLOGY Make a prediction: I think my reaction time will be faster with my (right/left) _____________ hand. Record your “catch distances” in the spaces below. Then use the “distance & time” chart to find how long it took you to catch the ruler. Right Hand Trial 1 2 3 4 Catch Distance Left Hand Reaction Trial Time (milliseconds) 1 2 3 4 Trial Catch Distance 1 2 3 4 Reaction Trial Time (milliseconds) 1 2 3 4 Use your 4th or last catch distance to determine your official reaction times. My right hand reaction time is ______________ milliseconds. My left hand reaction time is _______________milliseconds. “Do you remember your prediction? Was your prediction correct? Which hand was better at catching the ruler? Why was one hand faster than the other? TAKS Objective 2 page 22 BIOLOGY Central Nervous System 5 E’s ENGAGE EXPLORE Exploration 1 Clay Brains UNC-CH Brain Explorers Students will be introduced to basic brain anatomy. They will hear and say the terms associated with basic brain anatomy and create reasonably accurate clay models featuring all the major structures. Set-up: • How to Build a Brain Worksheet • Plastic Brain Models • Paper (to protect desks) • Set of clay in 4 or 5 colors for each student PROCEDURE • Display several small brain models to the class. • Tell students that they will be making brain models • Pass out the following to each student: out of clay. - a small resealable plastic bag containing four or five different colored cubes of modeling clay; - a blank sheet of paper to use as a work surface; and - a ‘How to Build a Brain’ worksheet. • Have a student read the first paragraph of the worksheet aloud to the class. This paragraph introduces the term ‘hemisphere’, and discusses why scientists use Greek and Latin terms. Have all the students create two hemispheres. TAKS Objective 2 page 23 BIOLOGY • Have another student read the next paragraph of the worksheet. This paragraph introduces the terms ‘cortex’ and ‘corpus callosum’. Encourage students to examine the small model brains to become familiar with where the structures are located in an actual brain • As the students finish each step of the directions, go around the room and make sure that the hemispheres are reasonably well shaped, and that the corpus callosum is in the proper position before the hemispheres are placed together. • When all the hemispheres are connected, ask a student to read the next paragraph of the worksheet. This paragraph introduces the terms ‘gyrus (pl. gyri)’and ‘sulcus (pl. sulci)’. Students can reproduce these structures either by rolling up gyri or drawing grooves (sulci) on their cortices with a pencil point. • Encourage students to refer to the model brains for guidance. • Ask a student to read the next paragraph of the worksheet. This introduces the term ‘cerebellum’; then instruct the students to make a cerebellum and attach it to their models. • Make sure the cerebellums are attached to the proper point on the clay models. Refer to the plastic models for proper placement. • Have the next paragraph read. This deals with the ‘brain stem’, the structure that connects the brain with the spinal cord. The students should make a brain stem and attach it to the proper location on their clay brains. • Go around the room and answer questions from the students. Again, encourage the use of proper vocabulary when the students ask questions. • After the clay brain models are completed, have the students use the checklist on the last page of the worksheet to make sure their models are correct. • Each student should show a classmate their model, naming all the parts on the checklist. • Go around the room and have various students name the parts of their models. EXPLAIN Complete the Nervous System PowerPoint presentation with discussion and then divide students into teams to explain and answer questions while playing neuro-jeopardy. See neuro-jeopardy power point. Students should be capable of answering questions like the ones that follow: TAKS Objective 2 page 24 BIOLOGY ELABORATE Elaboration 1 Nicotine in the Body and Brain The goal of this lab is for students to understand how cigarette smoke travels through the respiratory system and the bloodstream to the brain. Set-up: -Nicotine and the Respiratory System poster -White paper for each student -Colored pencils to share PROCEDURE Part I – Body: Brainstorming: Reasons for Smoking • Tell students that in today’s lab they will learn how cigarette smoke travels through the body. • First ask: What reasons might people have for smoking cigarettes? • Create a class web listing reasons people might smoke cigarettes. • Ask students what cigarettes are made of *tobacco, paper, filters.) • Describe the contents of cigarette smoke. These include nicotine, burned tar, ammonia, and carbon monoxide. • Ask where cigarette smoke goes after a person inhales. “Where in the body does it travel?” • Explain that nicotine enters the body through a nicotine/tar mixture that is inhaled from a lit cigarette both through the mouth and the nose. • Nicotine travels through the respiratory system before reaching the bloodstream. • Using the poster of the respiratory system, identify the different parts of the respiratory system. • Explain the sequence followed by nicotine as it travels through the respiratory system: -Air goes in through the nostril & into the nasal cavity. The pharynx is the area in the back of the throat, the larynx (voice box) is just below (posterior to) that. -Air then travels down the windpipe (trachea), which branches into two bronchi (one bronchus leads to each lung). -Once inside the lung the bronchi branch out into smaller tubes called bronchioles which lead to clusters of air sacs. The air sacs are called alveoli. Here, nicotine can move from the lungs into the bloodstream where it is delivered to all parts of the body including the brain. Emphasize that the tar is known to cause cancer and the nicotine is highly addictive. TAKS Objective 2 page 25 BIOLOGY • Ask students to use art materials to draw the human body and the path of cigarette smoke/nicotine from the cigarette to the brain. • Students can take any approach to their art work as long as they show the cigarette, and nicotine moving through the respiratory system into the lungs and then the brain. • The different parts of the respiratory system should be labeled. Part II – Brain: Set-up: -Neurotransmission dance materials (with the addition of nicotine-related items) -Labels -Props -Various musical instruments -Nicotine and Neurotransmission Poster • Ask students what happens next? • What effects do they think nicotine has on the brain? Explain the effects of nicotine on the body: 1. Increases in blood pressure and heart rate. 2. Faster respiration. 3. Constriction of arteries. 4. Stimulation of the central nervous system. • Review the process of neurotransmission. • Have students identify parts of this process that could be impacted by nicotine. • Ask students: what normally stimulates the nervous system? Try and illicit that when nerve cells are sending messages, neurotransmitters are required in the process to excite the cell. • Explain to students that nicotine acts like a neurotransmitter for specific receptors on nerve cells. • Nicotine over stimulates the cell, more than it is stimulated by the neurotransmitter which it normally binds with. • When there is no nicotine, the cell does not get as excited as when it binds with the normal neurotransmitter. This makes the smoker want to have another cigarette to achieve the same effect. • Be sure students understand that cigarettes have different effects for different people depending on the dose, their mood and their smoking history. • Also, scientists are not entirely certain how nicotine causes dependency and addiction. However, nicotine’s ability to alter the normal process of neurotransmission is thought to play a critical role. TAKS Objective 2 page 26 BIOLOGY Neurotransmission Dance • Using the Nicotine and Neurotransmission poster, clarify the effects discussed above. • Tell students they will now do the neurotransmission dance to show nicotine’s effects. • This neurotransmission dance will include three nerve cells. • Thus more props will be used and props for nicotine, including labels, and a nicotine costume will be introduced. • In Dance 1 neurotransmission is normal between all three cells, and includes four neurotransmitters at each synapse. • In Dance 2 neurotransmission does not occur between the first and second cell but nicotine enters between the second and third cell. Only two nicotine neurotransmitters are released but they excite the cell beyond normal transmission. • In Dance 3 neurotransmission occurs between cell 1 and 2 and is normal but neurotransmission between cell 2 and 3 barely excites the cell and does not result in the message being passed on, or the action potential being released in cell 3. EVALUATE 1. Using notes and text, students will compete to answer questions over the nervous system by playing Neurojeopardy. 2. After constructing a clay brain model, students will verbally identify 6 of 7 brain structures. 3. Students will construct a neuron model with 100% accuracy that contains dendrites, a cell body (soma), axon, and axon terminals. TAKS Objective 2 page 27 BIOLOGY TAKS Objective 2 page 28 BIOLOGY How to Build a Brain Today we are going to build a brain out of clay. To do this, we will need to make the different parts of a brain. The first part we need to make is a half of the biggest part of the brain, called a hemisphere. Hemisphere is a Greek word that means half (hemi) of a round shape (sphere). Scientists use Greek and Latin words to describe different shapes and structures. These are very old languages that scientists like to use to describe things they discover or observe. Two Hemispheres Two Hemispheres After you make one hemisphere, make another one the same size. The outside of the hemisphere is called the cortex. This is Latin word that means “bark”, like the bark of a tree. The cortex protects the inside of the brain the way the bark protects the inside of a tree. The two hemispheres are connected by a bridge called the corpus callosum. TAKS Objective 2 page 29 BIOLOGY These strange sounding words mean “hard body” in Latin. Put a small piece of clay in the middle of one of your hemispheres before you mold them together. The outside of the cortex is covered by shapes that look like wads of gum. One of these wads is called a gyrus. Two or more are called gyri. Gyrus is a Latin word that means ‘roll’ or ‘fold’. Between the gyri are lines or grooves. One of these lines is called a sulcus. This is another Latin word that means ‘furrow’, like the line a farmer cuts in the ground to plant seeds. Two or more of these are called sulci (sul-sigh). You can make gyri by rolling up thin piece of clay and sticking them onto the cortex. Now we need to make the cerebellum. The Cerebellum is made up of the two rounded shapes that look like a little brain at the back of the cortex. Cerebellum means ‘little brain’ in Latin. Roll up two smaller balls of clay and stick them where you see the cerebellum on the model. Squish them together a little, because unlike the hemispheres, the cerebellum is not made up of two separate pieces. Our brains are starting to look like real brains! Next we need to make a brain stem. The brain stem is what connects the brain to the spinal cord. The brain stem looks like the stem of a flower or an apple. You should stick your brain stem between the TAKS Objective 2 page 30 BIOLOGY two round shapes that make up the cerebellum. Look at the model if you are not sure where to put your brain stem. Unlike the model, the brain stem is really made out of one piece, like the cerebellum. Congratulations! You have built a brain! Can you name the different parts of your brain? Show someone your brain and point out the different parts. Here is a checklist of the parts your brain should have: *Right hemisphere *Left hemisphere *Corpus callosum (did you remember to put one between the hemispheres?) *What is the cortex? How is the cortex like a Roman dog? (One is ‘bark’ in Latin, the other barks in Latin.) Extra credit if you laughed. *Gyri *Sulci *Cerebellum *Brain stem Take your brains home and show the different parts to someone. How many of the parts did they know? TAKS Objective 2 page 31 BIOLOGY Nicotine and the Brain Normal Synaptic Conditions * Under normal synaptic conditions, neurotransmitters are released from Cell 1 to stimulate Cell 2. Cell 2 then becomes excited, releases its action potential and transmits neurotransmitters to Cell 3. Cell 3 subsequently is excited and releases its action potential and the transmission process continues. Nicotine in the Synapse * Below, Cell 2 does not receive any neurotransmitter stimulation from Cell 1. It does not get excite and does not transmit any messages to Cell 3. Nicotine enters the synapse and binds to the receptors on Cell 3 causing heightened excitation and neurotransmission. Synaptic Conditions After Nicotine *In the absence of nicotine, the normal transmission process is impaired. Normal stimulation of Cell 1 and subsequently Cell 2 is not enough to excite Cell 3. Cell 3 does not receive enough stimulation to release its action potential and continue the transmission process. TAKS Objective 2 page 32 BIOLOGY Peripheral Nervous System 5 E’s ENGAGE As a class visit IQ Test Labs at www.intelligencetest.com/reflex/index.htm Select various students to come to the computer and test their skills on the different reflex/reaction tests. This website states that scientific tests have shown that reaction times to simple tasks have high correlations with g the general intelligence factor. Students should have fun attempting these reaction time games. EXPLORE Muscle Messages UNC-CH Brain Explorer The goal of this lab is to reinforce the process of neuromuscular transmission with hands-on materials. Set-up: -Reaction Time poster -Nerve-muscle poster -Synapse poster -Neurotransmission felt kits -Synapse worksheet Procedure: • Review neuron structure with students. • Ask students “How can these neurons send messages to each other and to the muscle cell?” TAKS Objective 2 page 33 BIOLOGY • Let students hypothesize as to what structures might be involved in neurotransmission, which is the process of communication between nerve cells and other cells in the body. • Review the reaction process required to catch the ruler on the board: the eye, the visual cortex, the motor cortex, the spinal cord, and the muscle. • Tell students, “Let's focus on the neuron that carries the message from the spinal cord to the muscles in the hand.” This nerve cell body is in the spinal cord and its axon stretches out to the hand muscles. • Students may enjoy estimating the length of their axons by measuring the distance from the spinal cord to the hand with a meter stick. • Tell students that they will next learn all the details about how the message gets from the nerve cell to the muscle cell. TAKS Objective 2 page 34 BIOLOGY Explain (10 minutes) Introduction to Neurotransmission • Use the neurotransmission poster to explain the following sequence of events. 1. The dendrites of the nerve cell in the spinal cord get a message from the nerve cell in the motor cortex. 2. The nerve cell in the spinal cord gets excited which causes an electrical signal, or action potential, to move down the axon of the nerve cell (ie. the axon that travels down the arm from the spinal cord). Use the neuron and synapse posters to clarify the process. 3. Once the action potential reaches the axon terminal neurotransmitters are released and travel through the synaptic cleft (the space between the axon terminal of the nerve cell in the spinal cord and the receptors on the muscle cell) to neurotransmitter receptors on the muscle cell. 4. The neurotransmitters and neurotransmitter receptors bind, which causes the muscle cell to get very excited. 5. Once the muscle cell is excited then the muscle contracts (or moves). • There are different levels of excitation in the receiving muscle cell. Excitation is increased with the increase in neurotransmitters that are released. The cell must be excited to a certain state before the muscle is able to contract. Reaction Time Felt Kit • Explain to students that they now will put together and narrate the steps of neuromuscular transmission using a felt kit. • Introduce the felt kit parts and labels: placemat (white felt), neuron cell body with dendrites (blue felt), axon and axon terminal (gold bead chain), action potential (lightening bolt), neurotransmitters (fuzzy balls), neurotransmitter receptors(y-shaped felt), and muscle cell (arm, hand, and muscle felt shape). • Demonstrate the process once for the class, setting up and moving the various parts. Repeat the sequence of events for the students. • Students work in groups to put together the "neurotransmission scheme" on the placemat. • Encourage students to use the labels for each part of the kit and to practice narrating the process to each other using the labels. • Come together as a class and have a few student volunteers narrate the process for the class. • Be sure to remind students to use the materials carefully and make sure all the pieces get back in the bag for the next class. TAKS Objective 2 page 35 BIOLOGY Synapse Worksheet • In the box, students should draw and label the synapse using all the words listed • Students should then number the steps of neurotransmission from 1-6 beginning with # 1 (the nerve cell in the spinal cord receives a message from the nerve cell in the motor cortex). EXPLAIN Complete the Nervous System PowerPoint presentation with discussion and then divide students into teams to explain and answer questions while playing neuro-jeopardy. See neuro-jeopardy power point. Students should be capable of answering questions like the ones that follow: TAKS Objective 2 page 36 BIOLOGY ELABORATE Reflex Arc Lab http://educ.queensu.ca/~science/main/concept/biol/b06/B06LACW1.htm To study the simplest functional unit of the nervous system: the reflex arc. EVALUATE 1. Using notes and text, students will compete to answer questions over the nervous system by playing Neurojeopardy. 2. After constructing a clay brain model, students will verbally identify 6 of 7 brain structures. 3. Students will construct a neuron model with 100% accuracy that contains dendrites, a cell body (soma), axon, and axon terminals. TAKS Objective 2 page 37 BIOLOGY TAKS Objective 2 page 38 BIOLOGY TAKS Objective 2 page 39 BIOLOGY TAKS Objective 2 page 40 BIOLOGY Name: _________________ Date: _________________ Brain Explorers Neurotransmission Worksheet “Nerve cell to Muscle cell” Using the words on the left, label the picture by drawing a line to the parts of the picture. muscle cell cell body axon terminal dendrites nucleus nerve cell neurotransmitters Put the parts of the neurotransmission process in the correct order. Label them from 1 to 6 in the boxes to the left of each statement. After the nerve cell gets excited, it sends the action potential down the axon to the axon terminal. Once the neurotransmitters bind to the neurotransmitter receptors, the muscle contracts. Dendrites on the nerve cell in the spinal cord receive messages from another nerve cell. The neurotransmitters travel to the neurotransmitter receptors on the muscle cell. The nerve cell gets excited. When it reaches the axon terminal, neurotransmitters are released. TAKS Objective 2 page 41 BIOLOGY Name: _________________ Date: _________________ Brain Explorers Neurotransmission Worksheet “Nerve cell to Muscle cell” Teacher Key Using the words on the left, label the picture by drawing a line to the parts of the picture. Put the parts of the neurotransmission process in the correct order. Label them from 1 to 6 in the boxes to the left of each statement. 3 After the nerve cell gets excited, it sends the action potential down the axon to the axon terminal. 5 Once the neurotransmitters bind to the neurotransmitter receptors, the muscle contracts. 4 Dendrites on the nerve cell in the spinal cord receive messages from another nerve cell. 1 The neurotransmitters travel to the neurotransmitter receptors on the muscle cell. 2 The nerve cell gets excited. 6 When it reaches the axon terminal, neurotransmitters are released. TAKS Objective 2 page 42 BIOLOGY Reflex Arc Lab A: Purpose To study the simplest functional unit of the nervous system: the reflex arc. B: Materials percussion hammer, glass rod, filing cards, nail, flashlight, 20x20cm piece of newspaper, beaker C: Method Note: For the duration of this lab students should work in pairs 1. Patellar (knee-jerk) Reflex Have the subject sit on the edge of a table with one leg dangling freely. Strike the tendon just below the knee-cap with the hammer Record the results Sketch a diagram of the reflex arc and label the receptor, sensory neuron, dorsal root, white matter, gray matter, ventral root, motor neuron, and effectors. 2. Uvular Reflex Have the subject open his/her mouth widely and touch the uvula with a clean glass rod (or cue-tip). Record the results Of what value is this response to humans? 3. Pupillar Reflex Have the subject close his/her eyes for 2 minutes Hold a filing card along the bridge of the nose so the right eye is shielded from the left. Shine a bright light into the right eye as soon as the subject opens his eyes. Observe the pupils of both eyes and record the response. Explain the results What could happen if this reflex did NOT exist? TAKS Objective 2 page 43 BIOLOGY 4. Accommodation Reflex Focus both eyes on the tip of a pencil held at eye level and at arm's length. While focusing on the pencil tip, indicate whether or not the objects in the background are in focus. Keeping the same line of sight, focus on the objects in the background. What happens to the image of the pencil tip. The distance from the eye to the nearest object that can be focused on clearly is called the near point of vision. To find the near point: Cover one eye, and focus on a piece of newspaper. Gradually bring the newspaper closer and closer to your eye until the letters just go out of focus. Have your partner measure the distance (in cm) between the newspaper and your eye. Repeat steps 4 and 5 for the other eye. Record the near point for both eyes. Give a physiological explanation for what has occurred in both parts of this experiment. Why can a person not see objects clearly when they are positioned closer to the eye than the near point? What happens to the near point as a person ages? Why does this occur? http://educ.queensu.ca/~science/main/concept/biol/b06/B06LACW1.htm TAKS Objective 2 page 44 BIOLOGY