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Module1: Brain Anatomy Unit Overview
Materials
Anatomy Overview This unit provides a basic survey of brain anatomy in which students are able to see and touch a real human brain and learn about the complex network of cells it contains. It is easiest to begin the unit by asking the class what they know about brain cells. A short lesson on cellular anatomy can follow with the help of several pictures of neurons to point out dendrites, axon, cell body, etc. You will definitely want to keep the human brain(s) out of sight during this time to keep the students focused. Proceed to describe to them how many neurons are in a human brain (about a hundred billion) by using the jar of candies to illustrate the space a brain would take up if neurons were the size of those candies (roughly the volume of 50 classrooms). To show how so many neurons fit into such a small space, take a flat paper towel and crumple it up into a tiny ball and explain that the brain has many similar folds. Pictures of brains can be used here to point out the obvious folding of the cerebral cortex. At this point in the demonstration the whole human brain can be uncovered and you can ask the class to tell you what they notice about it. The class will probably have their gloves on by this point, but if they don’t, tell them to put on gloves so they can handle the brains. Some of the features you may want to point out and explain are the meninges, optic nerves and optic chiasm, the folding of cerebral cortex, cerebellum, spinal cord, and corpus callosum. Describe and point out the various functional divisions of the brain such as left and right hemispheres and frontal, occipital, parietal, and temporal cortex. Pass the brain to the students and ask them to handle it carefully as they pass it around. Not everyone will want to hold the brain, but most will at least want to touch it once. As the human brains make their way around the class, pass out the jars or tubes containing mouse, rat, chick, cat, and other brains. Ask the class to point out the differences and similarities between these brains and the human brain. One difference they will probably notice is the smooth surface of the rodent brains compared to human brains. This can give you a chance to talk about the phylogenetic development of certain brain structures, cerebral cortex being most obvious. As the whole brains are being passed around, uncover the human brain slices and pass them around as well. The easiest concept to present with the slices is the difference between gray matter and white matter. Discuss what gives each region its distinctive coloring. For the slices, the choice of which anatomical structures to point out, such as the basal ganglia, is up to you but its best to keep it simple. However, corpus callosum is one structure that is easier to point out and if you have talked about it already, the class can get a better view of it in the slices. If MRI images are available, pass them around (after slimy gloves are removed) and discuss how the living brain can be imaged using modern methods. If you have MRIs from abnormal brains, this may be a good time to discuss issues of brain injury and disease and point out particular abnormalities (tumors, infarcts, etc) on the MRIs. Conclude the session by reminding the class that our understanding of the brain is still rather limited and that diseases of the brain, such as Alzheimer’s disease, are still poorly understood. Encourage the class to read more about the brain and suggest that they can be ‘brain scientists’ too. |