Justin M. Boucher
This section of the unit details strategies to be used with each objective. These explanations correspond with lesson plans in the classroom activities section, and seek to explain those lessons as fully as possible. Each objective also corresponds to the web-sites in the resources section, which provides useful images, in addition to information to guide students in diagramming.
Objective 1: Identify and the parts and functions of a neuron.
As the building block of the nervous system on the cellular level, the neuron is a very good place to start when considering the anatomy of the brain and nervous system. The neuron is simple enough to be understood without prior study, yet complex enough to begin initiating students to the immense variety and complexity of our anatomy. The neuron demonstrates to students the great variation that can stem from a simple structure, and thereby demonstrates the value of understanding a basic structure as a means or understanding the larger whole. A simple diagram of a neuron including a cell body, axon, dendrites, nucleus and myelin sheath can show the structure of a typical neuron, while further study into the nervous system can demonstrate the different types of neurons
e.g. motor neuron, sensory neuron, and dorsal root ganglion.
Such a diagram allows the student to encapsulate various neurochemical processes into their simplest form, allowing also for the study of these processes. Since a correct diagram would require inclusion of a synapse and a visible space left between the axon terminals and the dendrites. This space, though small in the diagram, and much smaller in the body is one of the most important empty spaces in the body, and it is the center of much activity in the nervous system.
The students will not only include this space in their diagram, but also they will explain the function of the synapse. This explanation will require students to grasp the concept of neurotransmitters, and allow them to demonstrate that understanding. This step will be pivotal in this section of the unit because the students need to understand this process to understand the function of the entire nervous system. Furthermore, with this explanation in mind, students will be able to explain how messages are relayed from the brain to the rest of the body.
Explaining and diagramming a neuron serves another useful purpose as well. Not only will students be able to discuss and explain the most basic level of the nervous system, but also they will begin the process of diagramming anatomy in a way that is both simple and useful. In addition to building the student's understanding of neuroanatomy and neurochemical processes, this unit builds the student's ability to conceptualize complex ideas and put them down in the form of a diagram.
It is therefore necessary for the students to work their way up to more complex material. Assuming that the students have only limited experience in drawing schematic diagrams, it is necessary to build from the ground up in terms of their diagramming prowess. The neuron is a good place to start in diagramming, in that the diagram can accurately depict the anatomy of the cell, while also depicting its function in the synapse. The synapse diagram will serve the dual purpose of beginning the process of representing functions, which are difficult to depict.
Commonly these diagrams include triangles or squares to represent the neurotransmitters, and receptors. If the students continue this process it will be the beginning of their representation of anatomical processes in a figurative way. This will, of course, become critical when the unit moves on to diagramming much more complex structures and systems.
Objective 2
: Explain and Diagram the levels and functions of the Nervous System.
With the basics of diagramming and nervous system anatomy behind us, the unit will progress to a wider understanding of the nervous system, which will include all of its levels and divisions. This objective also marks the first foray in this unit into schematic diagramming. The diagram of the neuron, while functionally schematic, does not break down the representation into a substantially simpler form. At its heart the neuron diagram is anatomical rather than schematic in nature. As the unit progresses it will become necessary to represent functions in a strictly schematic way, given that the process, or structure itself would be unwieldy as a strictly anatomical diagram. So it will become necessary to break these processes down into a visual representation, and this is the first step in understanding schematic diagramming.
The transition from anatomical representation to schematic diagramming will take place in clearly defined steps. First the students will diagram the anatomy of the nervous system. Their diagrams will include the central and peripheral nervous system and as with neurons, will allow the teacher to remind them of the necessity of simplification, and exaggeration in diagramming anatomy. This anatomical diagramming will be similar to their earlier work in that it will represent a specific piece of the human anatomy.
The students will then be asked to diagram the less anatomically specific divisions in the nervous system. The divisions between the autonomic nervous system and the somatic nervous system, while essentially anatomical in nature would be very difficult to diagram in a strictly anatomical way. Any fully anatomical diagram of these different parts of the whole would have to include a complete diagram of the entire human body. While this would be a useful endeavor for most students to accomplish, it would also be a gargantuan undertaking. Therefore, these divisions need to be simplified to facilitate understanding and diagramming.
The students will begin with the autonomic nervous system, showing examples of organs and body parts affected by it. The diagram will also include the distinction between the sympathetic and parasympathetic functions. For example a student might include the heart as an example of an organ affected by the autonomic nervous system and then include notation of whether it was sympathetic, parasympathetic, or both.
Similarly, the students will be asked to diagram the somatic nervous system including affective (sensory) and effective (motor) elements. They may consider many different ways of doing this. These diagrams may include a broad picture of the human body, or they may simply be line drawings, with text boxes. In any event the diagrams will require specific information, without requiring a specific type of representation.
It will be necessary for this section to allow the student freedom of representation. While there are basic elements that must be present, each student will be encouraged to represent the systems in their own way, and examples will be offered of various ways of diagramming the system for the students' use. The goal of this individual representation is to shift gears from copying down someone else's picture, to creating their own.
At this point it will also be necessary to define and explain the difference between an anatomical and a schematic diagram. The distinction may be small when dealing with the nervous system, but it will grow larger when dealing with the brain and its structures and functions.
Finally, this section will require a combination of anatomical and schematic diagrams. To fully represent the nervous system, both kinds of representation are required. Given that the ultimate goal of the unit is a diagram of the whole brain and nervous system, the students need to be prepared to combine the two.
Objective 3
: Analyze and diagram the endocrine system.
In many cases the endocrine system, as a system which falls under the biological bases of behavior in the AP Psychology curriculum, is usually tacked on to the end of a unit on the brain and nervous system as almost an afterthought. Frequently the endocrine system is regarded as an inconvenient addition to the unit on biological bases of behavior. In this case, I think that generalization is unfair, and the endocrine system has a useful role to play in the grand scheme of this unit. This is especially true if one considers the hierarchy of these systems. As we progress through the unit we will move from the systems that act as messengers, to the systems actually responsible for control, the endocrine is just such a system.
As a system dealing with hormones as neurochemicals, the endocrine system could rightfully be taught immediately following the whole nervous system. Due to the similarity between hormones and neurotransmitters, it is necessary to discuss fully the distinction between a hormone and a neurotransmitter (that a neurotransmitter is released from a cell to a cell and a hormone travels the body through the bloodstream). Otherwise the endocrine system can be treated remarkably similarly to the whole nervous system in terms of its teaching.
The students will begin with a simple analysis of the system, including explaining the distinction between the endocrine system's hormones and the neurotransmitters used in the nervous system. This analysis will also include a brief run down of all of the glands and organs associated with the endocrine system. In this way the students will become familiar with the parts of the system, and begin to understand their function.
The students will then begin to discuss the functions of the endocrine system. At this stage the students will begin the process of diagramming the endocrine system, including its glands and hormones, in a diagram of the body to accentuate the notion of localized function. They will take part in an activity in which they are given the names of the glands and their functions, and they will need to deduce where the glands might exist based on their function. This will lead to a discussion of the actual locations and a comparison of the endocrine system and the nervous system as a means of control of the body.
The placement of the endocrine system in this unit, in relation to other systems, serves a third and final function. Through the control the hypothalamus exerts over the pituitary gland (responsible for growth and regulation of water and sale metabolism) the students will be initiated to the brain as the locus of control for these systems. Naturally enough the students will be given the opportunity to briefly approach the brain as an important part of system, without yet approaching the whole complexity of the brain. In this case the students will only see the parts of the brain that control directly other parts of the body through the endocrine system. In this way the students will come to appreciate the control the brain exerts as an introduction to the brain as an organ in and of itself.
Objective 4
: Analyze and Diagram the Brainstem.
With the endocrine system completed, and the admittedly simple notion that the brain is in control cemented, it will be time to turn to the brain itself. As we move to the brain, our combination of schematic and anatomical diagrams will become more important, and less pronounced. This unit is predicated on the notion that students will learn more effectively when given the freedom to diagram as they see fit, rather than following a prescribed plan. That being the case, the balance between strictly anatomical diagramming and schematic diagramming will need to be struck by the student, rather than by the teacher.
For the purposes of this objective the students will be limited to the brainstem (cerebellum, medulla, pons and the midbrain). In this way the students will begin to understand the divisions within the brain, and the different responsibilities and functions of each section of the brain. Furthermore the students will begin to appreciate the complexity of the brain, while approaching it in manageable parts.
The students will then create a schematic of the brainstem including the routes certain signals take from the brain to the body and back. This will be a process, which draws exclusively on textual resources, thereby allowing students to practice this skill in the absence of models to follow. When they have completed their diagram they will compare it to a diagram provided (see resources) and evaluate their own work.
The students will begin with discussion of parts of the brainstem. Explanation may be limited at this point given that these are unique structures within the brainstem, and given that there will be further study, only generalizations are needed. For example, it would suffice to say that the midbrain is responsible for the relaying of sensory material from the brainstem to the cortex. The key to this kind of discussion is that the students understand the fact that the brainstem relays material up to the brain and down to the body, as well as controlling some basic body functions.
The reasoning behind this kind of division is simple. While studying the endocrine system or the nervous system the list of potential functions of any given piece of those systems was relatively short. While both systems are quite complex, the brain is far more so. Therefore, unlike the other parts of this unit, the brain will be approached a bit more slowly to ensure proper organization of all its functions. These divisions will enable students to classify brain structures based on function, thus aiding in their understanding of the organ as a whole. For example, if given a question on the AP exam that asked about a hypothetical student's losing thought processes without losing body function, the students would be able to use this classification to determine that the problem existed in the cerebral cortex or the midbrain, while eliminating the rest of the brainstem as a culprit.
Objective 5
: Analyze and diagram the lobes and structures of the cortex along with their respective functions.
This objective will most likely take more than one day to master, and therefore multiple examples of brain diagramming and brain anatomy will be offered to aid students in their diagramming the cortex. It will be necessary at this point to deal with all of the remaining brain anatomy, and therefore this may be the most challenging objective to fulfill.
In an effort to approach this topic comprehensively, the lesson begins with a brief discussion of phrenology. The students will look into the history of phrenology using web resources, and discuss the successes and failures of this interesting "science". This will allow the students to assimilate the idea that like functions are located close to one another, while studying an interesting topic. The students will then discuss the "science" critically, taking what is useful (the notion that structures responsible for similar function might have similar location) while debunking the notion that complex function (like criminal behavior) might be so easily ascertained.
When this is complete students will look into and discuss the pieces of the brain to be dealt with, along with their function. This list should be exhaustive, covering the lobes, the various cortexes and other brain structures along with their functions.
When the students have an exhaustive list, a task, which might take quite some time, the students will be presented with the means by which function of the brain is studied through fMRI. The students will again use web resources to study the process of fMRI comparing it to phrenology. This will be a primer on creation of their own diagrams. It may be necessary to offer examples of schematics at this point. It may, however, be unnecessary given that they have already had a chance to diagram schematically in the previous lesson.
Once these parts of the lesson are complete, it will be up to the students to put them together in a meaningful way. The students will then use the information they have at hand, the diagrams and scans, as well as their books and the skills they have learned throughout the unit, to create their diagram of the brain and its functions. There will be not limits on this process other than the time available to complete it, and the students' abilities and imaginations. The grading procedure will be equally simple in that it will be based solely on whether or not the students have completely rendered all of the structures and topics required.
Objective 6
: Construct a Comprehensive Diagram of the brain nervous and endocrine systems, showing their levels, interactions, functions and influences on behavior.
For the purposes of this final objective, which also marks the cumulative project of the unit the students will be asked to put together everything they have learned to create a master diagram. This master diagram will include everything covered throughout the unit and may take one of two forms. Either the students will craft this diagram from scratch, combining new versions of their older diagrams into a combination anatomical and schematic diagram, or they will create a collage.
In the case of a wholly new diagram, the students will be expected to create a completely new work, which may have portions of other works, but must be new. This option will allow the teacher to fully assess the understanding of each individual student, while requiring each student to synthesize the material in a new way. The students will have, not only to rehash what they have already completed, but also include the connections between the systems already identified and diagrammed. These connections would make this new diagram substantially different from the old ones.
The chief drawback to this method is time. The students will undoubtedly require a great deal of time to complete such a diagram. Given that each individual part of the diagram would have taken at least a full lesson in class to complete. Students would therefore need a substantial quantity of time to finish a task this large.
If indeed the time such an activity would take is prohibitive, there is another option. A similar, if not as comprehensive assessment could come from allowing students to create a collage diagram, by combining all of their old diagrams into one larger diagram. Such a collage would require the students to include and demonstrate the connections and crossovers between one diagram and the next. This could be extremely useful, even though it would require less work on the student's part.
In this case, drawing the connections alone would allow students to explore the interactions between these systems, as well as discovering their interactions. The chief downfall of this method is that it would limit students in terms of creativity. In the case of a larger new diagram, the students would be granted the opportunity to rework sections of the unit, or diagrams they did not like. They would also be able to limit or eliminate redundancy. This would not be possible in the case of the collage, without major editing.
In any event the diagram should include a number of specific structures, centers, and systems. All of these pieces have been discussed already in the unit, and it may be useful to ask the students to list them all first. However, it is important to be clear with them that there is a set list of structures and systems which need to be included in their diagram. That list includes the neuron (including a cell body, axon, dendrites, nucleus and myelin sheath), the nervous system (including central, peripheral, sensory, motor, sympathetic and parasympathetic systems), the endocrine system (including its glands and hormones), the brainstem (including the cerebellum, medulla, pons and the midbrain) and the cortex (including lobes, hemispheres, and centers of control). The students should include all of these items in their final diagram to ensure a complete and full diagram.
On the whole the choice will be left to the teacher. AP psychology is such a complex and time constrained course, that either option might seem more palatable when the time comes. In the case of the comprehensive diagram, a teacher might decide that everything needed another once over to ensure synthesis. In the case of the collage, the unit might already be running long, or the students might just get it. At which point it might make much more sense to do the collage and bring the unit to a close. In any event the students will be left with an opportunity to synthesize their understanding, and the teacher will be left with an opportunity to assess it.