The HumanMaster Watermark Image: http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
Part I:Lobes, the Cerebral Cortex, and Cortical Regionsof the Brain
Objectives:• Students will be able to describe the general structure of theCerebrum and Cerebral Cortex.• Students will be able to identify the Cerebrum, the Lobes ofthe Brain, the Cerebral Cortex, and its major regions/divisions.• Students will be able to describe the primary functions ofthe Lobes and the Cortical Regions of the Brain.
Cerebrum -The largest division of the brain. It isdivided into two hemispheres, each of which isdivided into four lobes.CerebrumCerebrumCerebellumhttp://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
Cerebral CortexCerebral CortexCerebral Cortex - The outermost layer of graymatter making up the superficial aspect of thecerebrum.http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg
Cerebral Features:• Sulci – Small grooves dividing the gyri– Central Sulcus – Divides the Frontal Lobe from the ParietalLobe• Fissures – Deep grooves, generally dividing largeregions/lobes of the brain– Longitudinal Fissure – Divides the two Cerebral Hemispheres– Transverse Fissure – Separates the Cerebrum from theCerebellum– Sylvian/Lateral Fissure – Divides the Temporal Lobe from theFrontal and Parietal Lobes• Gyri – Elevated ridges “winding” around the brain.
Lobes of the Brain (4)• Frontal• Parietal• Occipital• Temporal* Note: Occasionally, the Insula is considered the fifth lobe. It is located deepto the Temporal Lobe.http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Lobes of the Brain - Frontal• The Frontal Lobe of the brain is located deep to theFrontal Bone of the skull.(Investigation: Phineas Gage)• It plays an integral role in the following functions/actions:- Memory Formation- Emotions- Decision Making/Reasoning- PersonalityInvestigation (Phineas Gage)Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Frontal Lobe - Cortical Regions• Orbitofrontal Cortex – Site of Frontal Lobotomies• Primary Motor Cortex (Precentral Gyrus) – Cortical siteinvolved with controlling movements of the body.• Broca’s Area – Controls facial neurons, speech, and languagecomprehension. Located on Left Frontal Lobe.– Broca’s Aphasia – Results in the ability to comprehend speech, butthe decreased motor ability (or inability) to speak and form words.• Olfactory Bulb - Cranial Nerve I, Responsible for sensation of Smell* Desired Effects:- Diminished Rage- Decreased Aggression- Poor EmotionalResponses* Possible Side Effects:- Epilepsy- Poor Emotional Responses- Perseveration (Uncontrolled, repetitiveactions, gestures, or words)
Lobes of the Brain - Parietal Lobe• The Parietal Lobe of the brain is located deep to theParietal Bone of the skull.• It plays a major role in the following functions/actions:- Senses and integrates sensation(s)- Spatial awareness and perception(Proprioception - Awareness ofbody/ body parts in space andin relation to each other)Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Parietal Lobe - Cortical Regions• Primary Somatosensory Cortex (PostcentralGyrus) – Site involved with processing of tactileand proprioceptive information.• Somatosensory Association Cortex - Assistswith the integration and interpretation ofsensations relative to body position and orientationin space. May assist with visuo-motor coordination.• Primary Gustatory Cortex – Primary siteinvolved with the interpretation of the sensation ofTaste.
Lobes of the Brain – Occipital Lobe• The Occipital Lobe of theBrain is located deep to theOccipital Bone of the Skull.• Its primary function is theprocessing, integration,interpretation, etc. of VISION andvisual stimuli.Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Occipital Lobe – Cortical Regions• Primary Visual Cortex – This is the primaryarea of the brain responsible for sight-recognition of size, color, light, motion,dimensions, etc.• Visual Association Area – Interpretsinformation acquired through the primary visualcortex.
Lobes of the Brain – Temporal Lobe• The Temporal Lobes are located on the sides of thebrain, deep to the Temporal Bones of the skull.• They play an integral rolein the following functions:- Hearing- Organization/Comprehensionof language- Information Retrieval(Memory and Memory Formation)Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Temporal Lobe – Cortical Regions• Primary Auditory Cortex – Responsible for hearing• Primary Olfactory Cortex – Interprets the sense ofsmell once it reaches the cortex via the olfactorybulbs. (Not visible on the superficial cortex)• Wernicke’s Area – Language comprehension.Located on the Left Temporal Lobe.- Wernicke’s Aphasia – Language comprehensionis inhibited. Words and sentences are not clearlyunderstood, and sentence formation may be inhibited ornon-sensical.
• Arcuate Fasciculus - A white matter tract that connects Broca’s Area andWernicke’s Area through the Temporal, Parietal and Frontal Lobes. Allowsfor coordinated, comprehensible speech. Damage may result in:- Conduction Aphasia - Where auditory comprehension and speecharticulation are preserved, but people find it difficult to repeat heardspeech.Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Click the Region to see its NameKorbinian Broadmann - Learn about the man who divided the Cerebral Cortex into 52 distinct regions:http://en.wikipedia.org/wiki/Korbinian_BrodmannModified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Lobes and Structures of the BrainB.A.C.D.E.F.G.http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
Lobes and Structures of the BrainB.A. (groove)C. (groove)D. E.F.G.B. Frontal LobeG. Parietal LobeF. Occipital LobeD. Temporal LobeA. Central Sulcus(groove)E. Transverse FissureC. Sylvian/Lateral Fissurehttp://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
Q: Assuming this comical situation was factuallyaccurate, what Cortical Region of the brain wouldthese doctors be stimulating?Copyright: Gary Larson
A: Primary Motor Cortex* This graphic representation of the regions of the Primary Motor Cortex andPrimary Sensory Cortex is one example of a HOMUNCULUS:Homunculus
Q: What do you notice about the proportionsdepicted in the aforementioned homunculus?Q: What is meant by depicting these body partsin such outrageous proportions?A: They are not depicted in the same scale representative ofthe human body.A: These outrageous proportions depict the cortical areadevoted to each structure.- Ex: Your hands require many intricate movements andsensations to function properly. This requires a great deal ofcortical surface area to control these detailed actions. Yourback is quite the opposite, requiring limited cortical area tocarry out its actions and functions, or detect sensation. Back-Hom.* Note: Homunculus literally means “little person,” and may refer to one whose body shape isgoverned by the cortical area devoted to that body region.
Further InvestigationPhineas Gage: Phineas Gage was a railroad worker in the 19th century living inCavendish, Vermont. One of his jobs was to set off explosive charges in large rock inorder to break them into smaller pieces. On one of these instances, the detonationoccurred prior to his expectations, resulting in a 42 inch long, 1.2 inch wide, metal rodto be blown right up through his skull and out the top. The rod entered his skull belowhis left cheek bone and exited after passing through the anterior frontal lobe of hisbrain.Frontal
Remarkably, Gage never lost consciousness, or quickly regained it (there is still somedebate), suffered little to no pain, and was awake and alert when he reached a doctorapproximately 45 minutes later. He had a normal pulse and normal vision, andfollowing a short period of rest, returned to work several days later. However, he wasnot unaffected by this accident.Learn more about Phineas Gage: http://en.wikipedia.org/wiki/Phineas_GageFrontalhttp://www.sruweb.com/~walsh/gage5.jpg
Q: Recalling what you have just learned regarding the frontal lobe, whatpossible problems or abnormalities may Gage have presented withsubsequent to this type of injury (remember the precise location of the rodthrough his brain)?A: Gage’s personality, reasoning, and capacity to understand and follow socialnorms had been diminished or destroyed. He illustrated little to no interest inhobbies or other involvements that at one time he cared for greatly. ‘After theaccident, Gage became a nasty, vulgar, irresponsible vagrant. His formeremployer, who regarded him as "the most efficient and capable foreman intheir employ previous to his injury," refused to rehire him because he was sodifferent.’Q: It is suggested that Gage’s injury inspired the development of what at onetime was a widely used medical procedure. What might this procedure be,and how does it relate to Gage’s injury?A: The frontal lobotomy. This has been used with the intention to diminishaggression and rage in mental patients, but generally results in drasticpersonality changes, and an inability to relate socially. This procedure islargely frowned upon today, with the development of neurological drugs astreatments.Frontal
ResourcesImages:• http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_brain.gif• http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg• http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg• http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif• http://www.math.tu-dresden.de/~belov/brain/motorcor2.gif• Larson, Gary. The Far Side.Phineas Gage:• http://www.sruweb.com/~walsh/gage5.jpg• http://soma.npa.uiuc.edu/courses/bio303/Image7.jpg• http://en.wikipedia.org/wiki/Phineas_Gage• http://science-education.nih.gov/nihHTML/ose/snapshots/multimedia/ritn/Gage/Broken_brain1.html
Suggested Supplementary Materials:1. Skeleton Outline for note-taking.2. Multiple Diagrams of the Human Brain.* Students will label features/lobes* Students will color-code cortical regions3. Worksheets (matching, short answer, etc.), centered around the functions of thelobes and regions of the cerebrum.4. A more in depth article on Phineas Gage. Read and discuss as a class - timepermitting.Suggested Assessments:1. Class/individual questioning throughout (especially at the conclusion of) thepresentation.2. Homework worksheets - discussed or collected in class.3. Students will take a test on the nervous system in which they will be responsiblefor the structures, lobes, regions, functions, etc.
Broad Concept: There is a relationship between structure andfunction in organ systems of humans.4.1 Explain how major organ systems in humans (e.g.,kidney, muscle, lung) have functional units (e.g., nephron,sarcome, alveoli) with specific anatomy that perform thefunction of that organ system.4.2 Describe how the function of individual systems withinhumans are integrated to maintain a homeostatic balance inthe body.* Note: This PowerPoint has been developed for Juniors andSeniors enrolled in Anatomy and Physiology Courses. Thus, thedetail of the concepts and information contained herein is fargreater than required by the state Biology standards listed above.Massachusetts State Biology Standards
National Standards:THE BEHAVIOR OF ORGANISMS:• Multicellular animals have nervous systems that generate behavior. Nervous systems are formedfrom specialized cells that conduct signals rapidly through the long cell extensions that make upnerves. The nerve cells communicate with each other by secreting specific excitatory andinhibitory molecules. In sense organs, specialized cells detect light, sound, and specific chemicalsand enable animals to monitor what is going on in the world around them.• Organisms have behavioral responses to internal changes and to external stimuli. Responses toexternal stimuli can result from interactions with the organisms own species and others, as well asenvironmental changes; these responses either can be innate or learned. The broad patterns ofbehavior exhibited by animals have evolved to ensure reproductive success. Animals often live inunpredictable environments, and so their behavior must be flexible enough to deal withuncertainty and change. Plants also respond to stimuli.• Like other aspects of an organisms biology, behaviors have evolved through natural selection.Behaviors often have an adaptive logic when viewed in terms of evolutionary principles.• Behavioral biology has implications for humans, as it provides links to psychology, sociology,and anthropology.