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1 CHAPTER 2 The Systems, Structures, and Cells That Make Up Your Nervous System Introduction Detailed Outline 2.1 General Layout of the Nervous System 2.2 Cells of the Nervous System 2.3 Neuroanatomical Techniques and Directions 2.4 The Spinal Cord 2.5 The Five Divisions of the Brain 2.6 Major Structures of the Brain Chapter At-A-Glance Instructor s Print Resources Supplements Lecture Instructor s Launcher 1 Manual for The Nervous Basics of System Biopsychology Chapter 2 Lecture Launcher 2 Neuroanatomical Techniques Exercise 2.1 Neurons, Neurons, Neurons Exercise 2.2 Neural Structure Quiz Exercise 2.3 Having Fun with Neuroanatomy Exercise 2.4 Evaluate Goals Key Terms Test Bank for Basics of Biopsychology Chapter 2 Transparencies for Physiological Psychology, Chapter 2, TSP06-TSP20, see Table of Contents, p. xiii Grade Aid for Basics of Biopsychology Chapter 2 Media Supplements Beyond the Brain and Behavior CD for Basics of Biopsychology Practice Tests for Chapter 2 Hard Copy for Chapter 2 Electronic Flashcards for Chapter 2 Digital Media Archive Log (DMA), and Appendix, see Table of Contents, pp. xvii-xviii and xxiii PowerPoint Presentation Instructor s Manual Additional Readings and Media Resources Professor Notes 14

2 CHAPTER 2 OVERVIEW Full file at Chapter 2 In Chapter 2, Pinel provides an overview of the structure of the nervous system. He starts by pointing out how some of the terms sound quite foreign mostly because they are. Neuroanatomists mostly used Latin or Greek words. In the section titled General Layout of the Nervous System, Pinel delineates the basic ways to divide the nervous system: central nervous system (CNS) versus peripheral nervous system (PNS), and somatic nervous system (SNS) versus autonomic nervous system (ANS). It is further explained that the ANS has two parts: consisting of sympathetic nerves and parasympathetic nerves. The outer coverings of the brain, or meninges, are discussed, as is the blood brain barrier. Next, Cells of the Nervous System covers the basic features of neurons, including the different classification schemes. Unipolar, bipolar, and multipolar neurons are defined and described. Finally, glial cells, or the glue of the brain, are discussed, and some recent results indicating a role for glial cells in transmission are elaborated upon. In Neuroanatomical Techniques and Directions, Pinel details three major methods used to demonstrate neurons and synapses. The Golgi stain, a silver impregnation technique, enables the visualization of all parts of individual neurons the cell body, dendrites, and the axon. Nissl staining enables one to visualize all the neurons present, and thus to make accurate neuronal counts. Electron microscopy was the first method to allow visualization of very fine details, such as the structure of the synapse. Today, scanning electron microscopy provides three-dimensional images of fine structural detail. The next section, The Spinal Cord, provides an overview of the basic structure of a segment of the spinal cord. The dorsal horn and ventral horn are detailed, and differences in sensory versus motor functions described. The Five Divisions of the Brain outlines the boundaries of the telencephalon, diencephalon, mesencephalon, metencephalon and myelencephalon. And finally, Major Structures of the Brain details the prominent structures found in each division. The reticular formation is found in the myelencephalon and metencephalon. The metencephalon also contains the pons and cerebellum. The mesencephalon houses the inferior and superior colliculi (the tectum), and the substantia nigra and red nucleus (the tegmentum). The diencephalon consists of the thalamus, a large collection of sensory relay nuclei, and the hypothalamus, a limbic structure that controls the pituitary gland. The telencephalon is the most expansive, containing the cerebral cortex, most of the limbic system, and basal ganglia. Approximately 90% of the cerebral cortex is neocortex in the human brain. The neocortex can be divided into frontal, parietal, temporal, and occipital lobes. The limbic system is comprised of the hippocampus, cingulate cortex, amygdala, septum, and mammillary bodies. The basal ganglia are comprised of the caudate, putamen, and globus pallidus. LEARNING OBJECTIVES OF CHAPTER 2 To give students a working knowledge of the nervous system. To teach about neuroanatomical techniques. To teach students some history surrounding neuroanatomical discoveries. To teach students how to assess neuroanatomical data. To assess how neuroanatomy is relevant to their lives. 15

3 Instructor s Manual Basics of Biopsychology, Pinel CHAPTER 2 LECTURE OUTLINE (key terms in boldface) LECTURE LAUNCHER 1: The Nervous System If you have such a model available, bring a rack-mounted skeleton to class and ask your students what such a bony artifact might tell them about neuroanatomy. If no such model is available, transparencies, slides, or digitized images of a full-body skeleton are fine substitutes. During this discussion, note that the skeleton can be used to define the difference between the CNS and the PNS; between the brain and spinal cord; and between the somatic and autonomic nervous systems. Depending on the level of detail you would like to go into, you can have your students palpate landmarks on their own skulls and necks to help them get oriented (e.g., external occipital protuberance, temporal bones of skull, and the spinous process of C-7 vertebrae). Introduction Neuroanatomical terms can be complex often derived from Latin or Greek words 2.1 General Layout of the Nervous System (Use transparencies TSP11-TSP13, and TPS20 or digital images , and Appendix I and III; see Tables of Contents for complete media listings.) Definition of terms central nervous system (CNS) brain and spinal cord (inside skull and spine) peripheral nervous system (PNS) nervous system outside skull and spine somatic nervous system (SNS) PNS that interacts with the environment afferent nerves carry sensory signals to CNS efferent nerves carry motor signals to skeletal muscles autonomic nervous system (ANS) part of the PNS that regulates the internal state o sympathetic nerves autonomic nerves from the lumbar and o thoracic regions of the spinal cord parasympathetic nerves autonomic nerves from the brain and sacral region of the spinal cord first sympathetic neuron synapses near the spinal cord and the second projects to the target tissue; the first parasympathetic neuron synapses close to the target and the second parasympathetic neuron has short axon o o O========< O=============================< sympathetic O==============================< O=======< parasympathetic 12 pairs of cranial nerves olfactory (I), optic (II), vagus (X); both afferent and efferent (sensory and motor) 16

4 Chapter 2 Meninges. ventricles, and cerebrospinal fluid meninges three protective membranes cerebrospinal fluid (CSF) fills the subarachnoid space (below meninges), central canal of the spinal cord, and lateral ventricles; supports and cushions the brain central canal runs the length of the spinal cord cerebral ventricles four large internal chambers in the brain; two lateral Blood brain barrier blood brain barrier mechanism that impedes the passage of toxic substances into the brain glucose actively transported, not affected by blood-brain barrier blood brain barrier selective (e.g., sex hormones pass into sexual areas of the brain) 2.2 Cells of the Nervous System (Use transparencies TSP06-TSP09 or digital images ) Anatomy of neurons neurons specialized for reception, conduction, and transmission of electrochemical signals variety of shapes and sizes o external anatomy of neurons cell body, cell membrane, dendrites, axon, axon hillock. myelin, nodes of Ranvier, buttons, and synapses o internal anatomy of neurons nucleus, microtubules, synaptic vesicles, neurotransmitters, endoplasmic reticulum, cytoplasm, ribosomes, and Golgi complex neuronal cell membrane lipid bilayer (two layers of fat molecules) channel proteins embedded in the membrane signal proteins transfer signal inside the neuron Classes of neurons number of processes multipolar neuron (having many processes), unipolar neuron (having one process), and bipolar neuron (two processes) interneurons neurons with short axons; integrate information aggregates of neurons nuclei (singular nucleus) in the CNS; ganglia (singular ganglion) in the PNS bundles of axons tracts in the CNS; nerves in the PNS Glial cells: the forgotten majority glia means glue oligodendrocytes form myelin, an axon coating in the CNS Schwann cells form myelin, an axon coating in the PNS; contribute to axonal regeneration in the PNS astrocytes star-shaped glial cells; function in the blood brain barrier microglia respond to injury or disease, clear waste glia may participate in transmission of signals 17

5 Instructor s Manual Basics of Biopsychology, Pinel LECTURE LAUNCHER 2: Neuroanatomical Techniques This is an opportunity to wow students with fantastic pictures of neurons. If you have any of you own material, that makes it all the more personal. If not, the Internet is full of beautiful photomicrographs of neurons. You may want to show some of the latest techniques or neurons that have made the covers of Nature or Science magazines. Remember to give proper credits when showing other people s work in class and teach students how and why to do the same. 2.3 Neuroanatomical Techniques and Directions (Use transparency TSP10 or digital images ) Some neuroanatomical techniques Golgi stain Camillo Golgi, an Italian physician, in the 1870 s discovered silver stain that selectively permeates neurons completely; good for showing dendrite trees Nissl stain developed by Franz Nissl, a German psychiatrist, in the 1880 s, shows all the neuronal cell bodies; enables cell counting electron microscopy uses an electron absorbing material and then passes a beam of electrons through the material; enables resolution of fine detail, such as synapses scanning electron microscopy three-dimensional image Direction in the vertebrate nervous system enables one to orient; some anatomical names include these terms anterior (rostral) towards the nose posterior (caudal) towards the tail dorsal back-side or the top of the head (bends at brainstem for bipedals) ventral belly-side or the bottom of the head medial towards the midline of the body lateral away from the midline of the body superior top of the brain inferior bottom of the brain proximal closer to the CNS (used comparatively) distal farther from the CNS (used comparatively horizontal sections slices of brain cut in parallel with the floor frontal sections slices of brain cut as viewed from the front of an individual sagittal sections slices of brain cut along the midline or a plane parallel to it cross sections slices of spinal cord cut at a right angle to its major axis 18

6 Chapter 2 Name: Exercise 2.1 Neurons, Neurons, Neurons There are many techniques that beautifully illustrate neurons. In this exercise you will either copy photomicrographs (photos of microscopic images) from academic journals in the library or print examples from journal articles or other websites on the Internet, then paste these examples on this page or attach on separate pages. You can access journals articles using PubMed at which links you to the National Library of Medicine. Any search engine, but particularly a science-specialized search engine such as Scirus at: will locate scientific articles, as well as websites maintained by governmental agencies, universities, and research institutes. Find photomicrographs of neurons. List journal reference (authors, year, journal, volume, and pages) or Internet webpage address and give credit to scientist, then paste photomicrograph. Journal reference or website Paste photomicrograph here or attach on separate sheet address and credits Golgi technique Nissl stain Other methods (e.g., fluorescent dyes) 19

7 Instructor s Manual Basics of Biopsychology, Pinel Exercise 2.1 Follow up After students have completed this assignment, have an in-class contest for the best picture of a neuron. Let the students vote among entries made by students who believe they found an excellent example and are willing to copy it onto a transparency that can be shown in class. (This activity can work even in a large classroom.) 2.4 The Spinal Cord (Use transparency TSP19 or digital images ) A cross section of spinal cord horn-shaped gray matter embedded in white matter gray matter cell bodies and unmyelinated fibers of interneurons white matter myelinated axons (gives white matter its color) dorsal root axons afferent unipolar neurons in dorsal root ganglia ventral roots motor efferents to skeletal muscle (SNS) or ganglia (ANS) dorsal horns receive sensory inputs ventral horns contain motor neurons 2.5 The Five Divisions of the Brain Three swellings in development forebrain, midbrain, and hindbrain Before birth, divisions expand to five o telencephalon forebrain o diencephalon forebrain o mesencephalon midbrain o metencephalon hindbrain o myelencephalon hindbrain Exercise 2.2 Neural Structure Quiz Using the Neural Structure Quiz available from Dr. John Krantz at the University of Hanover ( have students identify the 8 different parts of the neuron shown in the quiz. After each part is named, ask your students to assign a function to the named part. Using the neuron, you can also illustrate the general flow of neural information (somatodendritic to terminal button) in the cell, preparing students for material in the next chapter. 2.6 Major Structures of the Brain (Use transparencies TSP16-TSP18 or digital images , and Appendix V-VI.) Myelencephalon (medulla) reticular formation 100 tiny nuclei forming central core of brain stem; also called reticular activating system because of role in arousal, sleep, and attention damage to medulla is life threatening loss of cardiac and respiratory reflexes 20

8 Chapter 2 Metencephalon reticular formation pons connects with cerebellum cerebellum little cerebrum; controls movement Mesencephalon tectum roof of mesencephalon o inferior colliculi o superior colliculi tegmentum floor of the mesencephalon o periaqueductal gray gray matter around the cerebral aqueduct; involved in pain reduction (analgesia) o substantia nigra (black substance) sensorimotor function o red nucleus sensorimotor function Diencephalon thalamus sensory relay nuclei project to cortex (e.g., lateral geniculate nucleus; visual relay) o large, two lobed structure o massa intermedia connect two sides in some brains hypothalamus located below the thalamus o regulates motivated behaviors o regulates the secretions of the pituitary glands o mammillary bodies part of the hypothalamus optic chiasm where optic nerves decussate (cross the midline) contralateral projecting from one side of the body to the other side ipsilateral staying on the same side of the body Telencephalon largest division of human brain cerebral cortex (cerebral bark) outer bark of the cerebral hemispheres o mammals with smooth cortex lissencephalic o convoluted for humans o fissures large furrows (e.g., longitudinal fissure separates the left and right hemispheres) o sulci (singular sulcus) small furrows o gyri (singular gyrus) ridges between furrows o cerebral commissures connect the two hemispheres (e.g., corpus callosum) o central fissure separates frontal lobe from parietal lobe o lateral fissure separates temporal lobe from parietal and occipital lobe o 90% of human cortex is neocortex o neocortex has six layers (I VI) o neocortex has stellate cells (star-shaped) and pyramidal cells (pyramid-shaped) o pyramidal cells have an apical dendrite and long axons 21

9 Instructor s Manual Basics of Biopsychology, Pinel o 10% of cortex that is not neocortex is more primitive, and has less than six layers (e.g., hippocampus, a sea horse-shaped structure buried in the temporal lobe, and cingulate cortex both parts of the limbic system) o hippocampus plays key role in memory limbic system circuit of midline structures that circle the thalamus (limbic means ring ) o regulates motivated behaviors fleeing, feeding, fighting, and sexual behavior o includes hippocampus, cingulate cortex, mammillary bodies, amygdala, fornix, and the septum o amygdala almond-shaped structure in the anterior temporal lobe o cingulate cortex located above the corpus callosum o fornix fiber tract leaving the hippocampus to connect with the septum and mammillary bodies o septum midline structure at the anterior tip of the cingulate cortex basal ganglia a group of subcortical structures involved with voluntary movement o amygdala may also be part of the basal ganglia o caudate (tail-like) and putamen form the striatum o o globus pallidus located medial to the caudate and putamen pathway from substantia nigra to striatum degenerated in Parkinson s disease Exercise 2.3 Instructions In this exercise, students have to identify the correct anatomical name based on the description of its chief characteristics, location, and function. Next, students invent their own names for these very same neuroanatomical areas. You can refer students to Word Roots from Washington University at: This website lists many neuroanatomical names with Latin or Greek roots and the meanings of those words. You might give students some examples where neuroanatomical terms have been shortened, for example, the medulla oblongata shortened to medulla, and the nucleus tractus solitarius shortened to solitary nucleus. You should require students to put in effort when renaming the structure. They should try to think of names that would genuinely be suitable and recognizable by those who use the regular terminology. One goal of this exercise is to show students how difficult it is to come up with new names for brain regions that have established names, which are a bit obscure. You can explain how present researchers in biopsychology face this dilemma, insofar as they must deal with ancientsounding names. Although researchers can modify these terms slightly in their own writings, the changes must be minor so that the meaning is preserved and others know what they are talking about. You can also tell students how there are often multiple terms for the same brain region (e.g., striate cortex is the same as primary visual cortex, etc.). 22

10 Chapter 2 Name: Exercise 2.3 Having Fun with Neuroanatomy Neuroanatomical structures have seemingly ancient names, which in many cases are Latin or Greek in derivation. Often these names are suggestive of the structure s pigmentation or shape (e.g., the hippocampus is named for its sea-horse shape, and the amygdala is named for its almond shape). Students often complain that neuroanatomical names are difficult to learn because the language is awkward and out-of date. Here is your chance to do a better job at naming neuroanatomical structures. Be sincere and try to think of names that relate to the shape, pigmentation, or function of the structure, yet are simple and modern. Description of the neuroanatomical structure This structure is found in the midbrain and has a dark, blackish pigment. It participates in voluntary motor functions. This is a small version of the cerebrum found in the hindbrain. It is involved with fast, repetitive movements. This collection of nuclei forms a large, two-lobed structure responsible for relaying different kinds of sensory information. These matched protruding structures are found in the midbrain and are involved with vision. This structure has a tail-like shape and its function is related to voluntary movement. Given Name You intent a new, more contemporary name This structure is composed of fibers circling around the thalamus connecting the hippocampus with the septum. 23

11 Instructor s Manual Basics of Biopsychology, Pinel Exercise 2.4 Evaluate Goals Refer back to initial goals at the outset of the chapter. Ask students if they are now much more comfortable with neuroanatomical terms. If not, reassure them that repeated exposure to these terms throughout the course will help these terms become more familiar. KEY TERMS (page numbers in Pinel text) afferent nerves (p. 37) amygdala (p. 56) anterior (p. 48) astrocytes (p. 45) autonomic nervous system (ANS) (p. 37) basal ganglia (p. 56) bipolar neuron (p. 43) blood brain barrier (p. 40) caudate (p. 56) cingulate cortex (p. 56) cingulate gyrus (p. 56) central canal (p. 39) central fissure (p. 55) central nervous system (CNS) (p. 37) cerebellum (p. 52) cerebral aqueduct (p. 53) cerebral commissures (p. 55) cerebral cortex (p. 54) cerebral ventricles (p. 39) cerebrospinal fluid (CSF) (p. 39) contralateral (p. 54) corpus callosum (p. 55) cranial nerves (p. 38) cross section (p. 48) decussate (p. 54) diencephalon (p. 53) dorsal (p. 48) dorsal horns (p. 49) efferent nerves (p. 37) electron microscopy (p. 47) fissures (p. 54) fornix (p. 56) frontal lobe (p. 55) frontal sections (p. 48) ganglia (p. 44) glial cells (p. 44) globus pallidus (p. 57) Golgi stain (p. 46) gyri (p. 54) hippocampus (p. 56) horizontal sections (p. 48) hypothalamus (p. 53) inferior (p. 48) inferior colliculi (p. 53) interneurons (p. 43) ipsilateral (p. 54) lateral (p. 48) lateral geniculate nuclei (p. 53) lateral fissure (p. 55) limbic system (p. 56) longitudinal fissure (p. 55) mammillary bodies (p. 54) massa intermedia (p. 53) medial (p. 48) medulla (p. 51) meninges (p. 39) mesencephalon (p. 53) metencephalon (p. 52) microglia (p. 45) multipolar neuron (p. 43) myelencephalon (p. 51) neocortex (p. 55) nerves (p. 44) Nissl stain (p. 47) nuclei (p. 44) occipital lobe (p. 55) oligodendrocytes (p. 44) optic chiasm (p. 54) parasympathetic nerves (p. 38) parietal lobe (p. 55) periaqueductal gray (p. 53) peripheral nervous system (PNS) (p. 37) pituitary gland (p. 54) peripheral nervous system (PNS) (p. 37) pons (p. 52) postcentral gyrus (p. 55) posterior (p. 48) precentral gyrus (p. 55) putamen (p. 57) pyramidal cells (p. ) red nucleus (p. 53) reticular formation (p. 51) 24

12 Chapter 2 sagittal sections (p. 48) Schwann cells (p. 44) septum (p. 56) somatic nervous system (SNS) (p. 37) striatum (p. 57) substantia nigra (p. 53) superior (p. 48) superior colliculi (p. 53) superior temporal gyrus (p. 55) sympathetic nerves (p. 38) tectum (p. 53) tegmentum (p. 53) telencephalon (p. 54) temporal lobe (p. 55) thalamus (p. 53) tracts (p.44 ) unipolar neurons (p. 43) ventral (p. 48) ventral horns (p. 49) 25

13 Instructor s Manual Basics of Biopsychology, Pinel ADDITIONAL READINGS AND MEDIA RESOURCES BOOKS A Colorful Introduction to the Anatomy of the Human Brain: A Brain and Psychology Coloring Book (1998) by John Pinel and Maggie E. Edwards, Allyn & Bacon The Human Brain Coloring Book (1986) by M.C. Diamond, A.B. Scheibel, & L.M. Elson, Harper Collins Publishers. MOVIES Anatomy of the Human Brain (1997) (DVD, VHS; 35 minutes) Films for the Humanities and Sciences. (Dissection of the human brain.) The Brain (1995) (DVD, VHS; 20 minutes) Films for the Humanities and Sciences. (Brain structure and function.) WEBSITES The National Library of Medicine (PubMed): Scirus (a science-based search engine): Wikipedia on Brain: Autonomic Nervous System: from The National Dysautonomia Research Foundation site: Neurons and Glia from Dr. Eric Chudler at the University of Washington. Scroll down to "Neurons" to find information about neurons, glia, and a photo gallery of cells at: Neuroanatomy Quiz: Dr John Krantz's study aids and tutorials for biopsychology at: Interactive Brain Atlas from the Digital Anatomist project at the University of Washington. Select the BRAIN icon for a collection of images in many different planes of section, digital recreations of different functional systems in the brain: Brain Anatomy from McGill University. An introduction to neuroanatomy, with different levels of complexity (beginner to advanced) and levels of organization (from social aspects to molecular aspects of neuroanatomy): Word Roots: A source for the Greek and Latin roots of many neuroanatomical terms: 3D Brain Atlas from Brain Networks Laboratory at Texas A & M University: 26