PDF - Neuroanatomy: Temporal, Parietal, Frontal Lobes

Chapter 3 NeuroAnatomy (Module 3.2) © Cengage Learning 2016 © Cengage Learning 2016  Notes on how to watch and listen! First download the lecture to your computer from Canvas Then Click the Slide Show Tab at the top of the presentation Then Under the Slide...

Chapter 3 NeuroAnatomy (Module 3.2) © Cengage Learning 2016 © Cengage Learning 2016  Notes on how to watch and listen! First download the lecture to your computer from Canvas Then Click the Slide Show Tab at the top of the presentation Then Under the Slide Show Tab, click From Current Slide The presentation will automatically advance for you after you advance to the next slide in this presentation © Cengage Learning 2016  4 Lobes of Cerebral Cortex and Associated Functions © Cengage Learning 2016  More detail on the Four lobes of the Cerebral Cortex Occipital lobe Parietal lobe Temporal lobe Frontal lobe © Cengage Learning 2016  The Occipital Lobe Highly responsible for visual input – Damage can result in cortical blindness only in related part of visual field (optic nerve is not damaged) – Due to lack of communication between the brain and the eyes – Eyes can see but brain can’t interpret what you are seeing. © Cengage Learning 2016  Compelling video on cortical blindness https://www.youtube.com/watch?v=g- h_j3HEJTg © Cengage Learning 2016  The Parietal Lobe, Part 1 Contains the postcentral gyrus (“primary somatosensory cortex”) – Primary target for touch sensations and information from muscle-stretch receptors and joint receptors Also responsible for processing and integrating information about eye, head, and body positions from information sent from muscles and joints © Cengage Learning 2016  The Parietal Lobe, Part 2 Essential for spatial information as well as numerical information – Example: using one’s fingers to count represents an overlap of spatial and numerical tasks © Cengage Learning 2016  Damage to the Parietal Lobe Right-left confusion, Difficulty with writing (agraphia) and Difficulty with mathematics (acalculia). Disorders of language (aphasia) Inability to perceive objects normally (agnosia). © Cengage Learning 2016  The Temporal Lobe Located on the lateral portion of each hemisphere near the temples – Target for auditory information and essential for processing spoken language Also responsible for complex aspects of vision, including movement and some emotional and motivational behaviors – Klüver-Bucy syndrome (hyperphagia, hypersexuality, oral fixations, fearless) associated with temporal lobe damage © Cengage Learning 2016  The Frontal Lobe is not just for executive function! Contains the prefrontal cortex and the precentral gyrus – Precentral gyrus: also known as the primary motor cortex; responsible for the control of fine motor movement – Prefrontal cortex: the integration center for all sensory information and other areas of the cortex (most anterior portion of the frontal lobe) © Cengage Learning 2016  Species Differences in Prefrontal Cortex Note: The prefrontal cortex (blue area)in humans constitutes a larger proportion of the brain compared to other species. © Cengage Learning 2016  The Prefrontal Cortex Responsible for: – Higher functions such as abstract thinking and planning – Our ability to remember recent events and information (“working memory”) People with damage to the prefrontal cortex exhibit delayed-response task – Respond to something they see or hear after a delay – Bad judgement, angry outbursts (Phineas Gage) © Cengage Learning 2016  Prefrontal Lobotomy How doctors used to “treat” mental illness! Surgical disconnection of the prefrontal cortex from the rest of the brain – In the 1940s and 50s, about 40,000 performed – Mostly, schizophrenics, but later others with less severe mental illness – Patients left with apathy, lack of ability to plan, memory disorders and lack of emotional expression © Cengage Learning 2016  Rosemary Kennedy Prefrontal Lobotomy 1941 Part of the famous Kennedy family (JFK’s sister), she was forced to get a prefrontal lobotomy to control her seizures and mood swings. It had disastrous effects. © Cengage Learning 2016  Results of a Prefrontal Lobotomy © Cengage Learning 2016  Temporal Lobotomy for Epilepsy Temporal lobotomy most common way to treat severe epilepsy. Removes a portion of the anterior temporal lobe, the amygdala, and the hippocampus It leads to a significant reduction or complete seizure control in about 70% to 80% of patients. © Cengage Learning 2016  More on Temporal Lobotomy Even though temporal lobotomy is an effective treatment for seizures, It can have very serious, and disastrous psychiatric (e.g., depression, anxiety)and mixed cognitive consequences in patients! Think about why this may be the case! Hint: Think about brain regions that are impacted by the lobotomy. © Cengage Learning 2016  Phineas Gage Many of you know the story of Phineas Gage, prior to her accident he was organized, even-tempered. Initially after damage to the prefrontal area, he had drastic changes in his personality (i.e., angered easily). Several years after the accident, there were reports that his behavior improved. Suggesting that the effects of the damage to the brain were temporary. © Cengage Learning 2016  The Forebrain – The Limbic System Consists of a number of other interlinked structures that form a border around the brainstem – Includes the olfactory bulb, hypothalamus, hippocampus, amygdala, and other structures – Associated with motivation, memory emotions, such as eating, drinking, sexual activity, anxiety, and aggression © Cengage Learning 2016  The Forebrain – Subcortical Regions Structures underneath the cortex – Thalamus: relay station from the sensory organs; main source of input to the cerebral cortex – Hypothalamus: small area near the base Conveys messages to the pituitary gland to alter the release of hormones Associated with behaviors such as eating, drinking, sexual behavior, stress The thalamus and the hypothalamus together form the “diencephalon” © Cengage Learning 2016  Hypothalamus Easy Reminder: It is often said that the hypothalamus is responsible for the four Fs: fighting, fleeing, feeding, and fornication © Cengage Learning 2016  Pituitary gland hormone-producing gland found at the base of the hypothalamus Anterior Pituitary Gland Hormones released by the neurosecretory cells in the hypothalamus enter capillaries and are conveyed to the anterior pituitary gland, where they control its secretion of hormones (e.g., ACTH) Posterior Pituitary Gland Hormones of the posterior pituitary gland are produced in the hypothalamus and carried here in vesicles by means of axoplasmic transport (e.g., oxytocin, vasopressin) © Cengage Learning 2016  The Forebrain –Basal Ganglia Basal ganglia: comprises the caudate nucleus, the putamen, and the globus pallidus – Associated with planning of motor movement, and with aspects of memory and emotional expression – Also important for attention, language planning, and other cognitive functions **Damage linked to like Parkinson’s disease and Huntington’s disease (both cause profound issues with movement) © Cengage Learning 2016  The Forebrain – The Basal Forebrain Composed of several structures that lie on the dorsal surface of the forebrain Contains the nucleus basalis – Receives input from the hypothalamus and basal ganglia – Sends axons that release acetylcholine to the cerebral cortex – Important in arousal, wakefulness, and attention – (area severely affected with e.g., Alzheimer’s disease) © Cengage Learning 2016  The Forebrain – The Hippocampus A large structure located between the thalamus and cerebral cortex – Toward the posterior portion of the forebrain – Critical for storing certain types of memory, particularly new events **Impacted by Alzheimer’s too! © Cengage Learning 2016  Brain Development Fact The frontal lobe is the most recently-evolved part of the brain and the last to develop in young adulthood. The brain develops in a specific sequence, from the most basic parts to the most complex ones. The brain stem begins developing first, followed by the cerebellum, the limbic system, and finally the cerebral cortex. © Cengage Learning 2016  Sagittal Section Through the Human Brain This is just another view of the brain that shows some of the areas of the brain on one image. This is just for you to have as a reference. © Cengage Learning 2016