{"id":2609,"date":"2025-05-19T09:19:05","date_gmt":"2025-05-19T08:19:05","guid":{"rendered":"https:\/\/myknowledgehub.org\/?page_id=2609"},"modified":"2025-05-20T04:41:47","modified_gmt":"2025-05-20T03:41:47","slug":"chapter_3_2","status":"publish","type":"page","link":"https:\/\/myknowledgehub.org\/index.php\/evb_home\/modules_theory\/chapter_3_2\/","title":{"rendered":"EVB Chapter_3_2"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"2609\" class=\"elementor elementor-2609\">\n\t\t\t\t<div class=\"elementor-element elementor-element-7bad944 e-flex e-con-boxed e-con e-parent\" data-id=\"7bad944\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-dead2f1 elementor-widget elementor-widget-spacer\" data-id=\"dead2f1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-6f8f7e8 e-flex e-con-boxed e-con e-parent\" data-id=\"6f8f7e8\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-c9db006 elementor-widget elementor-widget-heading\" data-id=\"c9db006\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Chapter 3.2\n<br>\nNervous System in Vertebrates (Fishes to Mammals)<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-9cbb10c e-flex e-con-boxed e-con e-parent\" data-id=\"9cbb10c\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-3b640fc elementor-widget elementor-widget-spacer\" data-id=\"3b640fc\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-a38fb1b e-flex e-con-boxed e-con e-parent\" data-id=\"a38fb1b\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-c76b677 elementor-widget elementor-widget-heading\" data-id=\"c76b677\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">A. Brain, Spinal Cord and Peripheral Nerves<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-c125d08 e-flex e-con-boxed e-con e-parent\" data-id=\"c125d08\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-8ccba27 elementor-widget elementor-widget-image\" data-id=\"8ccba27\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"682\" src=\"https:\/\/myknowledgehub.org\/wp-content\/uploads\/2025\/05\/gf6455fc1af07f94176e7cb3039a145d48e371fb381720da1968c37f65ed22b94bbf578bb416172c53359f2e62ef8434c_1280-114079-1024x682.jpg\" class=\"attachment-large size-large wp-image-2666\" alt=\"brain, horse, section, anatomy, preparation, cerebellum, cerebrum, brain stem, science, nature, biology\" srcset=\"https:\/\/myknowledgehub.org\/wp-content\/uploads\/2025\/05\/gf6455fc1af07f94176e7cb3039a145d48e371fb381720da1968c37f65ed22b94bbf578bb416172c53359f2e62ef8434c_1280-114079-1024x682.jpg 1024w, https:\/\/myknowledgehub.org\/wp-content\/uploads\/2025\/05\/gf6455fc1af07f94176e7cb3039a145d48e371fb381720da1968c37f65ed22b94bbf578bb416172c53359f2e62ef8434c_1280-114079-300x200.jpg 300w, https:\/\/myknowledgehub.org\/wp-content\/uploads\/2025\/05\/gf6455fc1af07f94176e7cb3039a145d48e371fb381720da1968c37f65ed22b94bbf578bb416172c53359f2e62ef8434c_1280-114079-768x512.jpg 768w, https:\/\/myknowledgehub.org\/wp-content\/uploads\/2025\/05\/gf6455fc1af07f94176e7cb3039a145d48e371fb381720da1968c37f65ed22b94bbf578bb416172c53359f2e62ef8434c_1280-114079.jpg 1280w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-8f68ff9 e-flex e-con-boxed e-con e-parent\" data-id=\"8f68ff9\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-c20e71a elementor-widget elementor-widget-text-editor\" data-id=\"c20e71a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<h6><span style=\"color: #0000ff;\"><strong>Introduction<\/strong><\/span><\/h6><p><strong>Definition and Basic Functions<\/strong><br \/>The nervous system is a highly specialized network responsible for: <br \/>i) <strong>Sensory Input <\/strong>(detecting environmental stimuli), ii) <strong>Integration<\/strong> (processing information in the brain and spinal cord), and iii) <strong>Motor Output <\/strong>(coordinating muscle and gland responses).<\/p><h6>\u00a0<\/h6><h6><span style=\"color: #0000ff;\"><strong>I. Divisions of the Nervous System<\/strong><\/span><\/h6><p>1. <strong>Central Nervous System (CNS)<\/strong>:<\/p><ul><li>Brain and spinal cord.<\/li><li>Integrates and processes information.<\/li><\/ul><p>2. <strong>Peripheral Nervous System (PNS)<\/strong>:<\/p><ul><li>Cranial and spinal nerves.<\/li><li>Connects CNS to limbs and organs.<\/li><\/ul><h6>\u00a0<\/h6><h6><span style=\"color: #0000ff;\"><strong>II. Evolutionary Overview of Vertebrate Nervous Systems<\/strong><\/span><\/h6><p><strong>Key Transitions<\/strong><\/p><ul><li><strong>Early Chordates<\/strong> (e.g., Lancelets): Simple nerve cord, no true brain.<\/li><li><strong>Jawless Fish<\/strong> (Agnatha): Rudimentary brain regions (hindbrain, midbrain, forebrain).<\/li><li><strong>Gnathostomes<\/strong> (Jawed Vertebrates): Enhanced sensory and motor regions.<\/li><li><strong>Tetrapods<\/strong>: Expansion of forebrain (cerebrum) for complex behaviours.<\/li><\/ul><h6>\u00a0<\/h6><h6><span style=\"color: #0000ff;\"><strong>III. Comparative Neuroanatomy Across Vertebrates<\/strong><\/span><\/h6><p><strong>A. Brain Structure and Function<\/strong><\/p><p><strong>1) Fishes<\/strong><\/p><ul><li><strong>Forebrain (Telencephalon)<\/strong>: Olfactory processing.<\/li><li><strong>Midbrain (Optic Tectum)<\/strong>: Visual reflexes.<\/li><li><strong>Hindbrain (Medulla Oblongata)<\/strong>: Controls swimming.<\/li><\/ul><p><strong>2) Amphibians<\/strong><\/p><ul><li><strong>Larger Optic Lobes<\/strong>: Enhanced vision for hunting.<\/li><li><strong>Primitive Cerebellum<\/strong>: Coordinates movement on land.<\/li><\/ul><p><strong>3) Reptiles<\/strong><\/p><ul><li><strong>Expanded Cerebrum<\/strong>: Better spatial memory. <br \/><strong>Pineal Gland (&#8220;Third Eye&#8221;)<\/strong>: Light detection in some species.<\/li><\/ul><p><strong>4) Birds<\/strong><\/p><ul><li><strong>Hyperdeveloped Optic Lobes<\/strong>: Superior vision.<\/li><li><strong>Enlarged Cerebellum<\/strong>: Flight coordination.<\/li><\/ul><p><strong>5) Mammals<\/strong><\/p><ul><li><strong>Neocortex<\/strong>: Complex cognition, problem-solving.<\/li><li><strong>Corpus Callosum<\/strong>: Connects brain hemispheres.<\/li><\/ul><p><strong>B. Spinal Cord Organization<\/strong><\/p><p><img decoding=\"async\" class=\"alignnone wp-image-2617 size-full\" src=\"http:\/\/myknowledgehub.org\/wp-content\/uploads\/2025\/05\/0Table-10.png\" alt=\"\" width=\"574\" height=\"235\" srcset=\"https:\/\/myknowledgehub.org\/wp-content\/uploads\/2025\/05\/0Table-10.png 574w, https:\/\/myknowledgehub.org\/wp-content\/uploads\/2025\/05\/0Table-10-300x123.png 300w\" sizes=\"(max-width: 574px) 100vw, 574px\" \/><\/p><p><strong>C. Peripheral Nervous System<\/strong> <strong>Adaptations<\/strong><\/p><ul><li><strong>Electroreception<\/strong>: Sharks detect electric fields.<\/li><li><strong>Vomeronasal Organ<\/strong>: Reptiles and mammals detect pheromones.<\/li><\/ul><h6>\u00a0<\/h6><h6><span style=\"color: #0000ff;\"><strong>IV. Major Evolutionary Milestones<\/strong><\/span><\/h6><p><strong>A. Development of Myelination<\/strong> (~400 MYA)<\/p><ul><li><strong>Myelin Sheath<\/strong>: Insulates axons for faster signal transmission.<\/li><li><strong>First Appeared in<\/strong>: Jawed vertebrates.<\/li><\/ul><p><strong>B. Encephalization<\/strong> (~320 MYA\u2013Present)<\/p><ul><li><strong>Brain-to-Body Size Ratio<\/strong>: Increased in mammals and birds.<\/li><li><strong>Cortical Folding<\/strong>: Maximizes surface area (e.g., human gyri and sulci).<\/li><\/ul><p><strong>C. Specialized Sensory Systems<\/strong><\/p><ul><li><strong>Lateral Line System<\/strong>: Fish detect water vibrations.<\/li><li><strong>Echolocation<\/strong>: Bats and toothed whales.<\/li><\/ul><h6>\u00a0<\/h6><h6><span style=\"color: #0000ff;\"><strong>V.\u00a0 Functional Adaptations in Different Classes<\/strong><\/span><\/h6><p><strong>A. Fishes<\/strong><\/p><ul><li><strong>Mauthner Cells<\/strong>: Rapid escape responses.<\/li><li><strong>Electrosensory Ampullae<\/strong>: Detect prey in murky water.<\/li><\/ul><p><strong>B. Amphibians<\/strong><\/p><ul><li><strong>Binocular Vision<\/strong>: Accurate prey targeting.<\/li><li><strong>Vibrational Sensing<\/strong>: Detect ground-borne sounds.<\/li><\/ul><p><strong>C. Reptiles<\/strong><\/p><ul><li><strong>Infrared Pit Organs<\/strong>: Snakes sense heat.<\/li><li><strong>Basal Ganglia<\/strong>: Controls instinctive behaviours.<\/li><\/ul><p><strong>D. Birds<\/strong><\/p><ul><li><strong>Nidopallium Caudolaterale<\/strong>: Avian equivalent of prefrontal cortex.<\/li><li><strong>Magnetic Sensing<\/strong>: Navigate using Earth\u2019s magnetic field.<\/li><\/ul><p><strong>E. Mammals<\/strong><\/p><ul><li><strong>Prefrontal Cortex<\/strong>: Decision-making, social behaviour.<\/li><li><strong>Spinothalamic Tract<\/strong>: Pain and temperature perception.<\/li><\/ul><h6>\u00a0<\/h6><h6><span style=\"color: #0000ff;\"><strong>Conclusion<\/strong><\/span><\/h6><p>The vertebrate nervous system showcases <strong>progressive complexity<\/strong>, from the simple nerve nets of early fish to the highly encephalized brains of mammals. Key innovations include: i) <strong>Myelination<\/strong> for rapid signaling, ii) <strong>Encephalization <\/strong>for supporting advanced cognition, and iii) <strong>Specialized Sensory <\/strong>ability to ecological niches.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-2821eb8 e-flex e-con-boxed e-con e-parent\" data-id=\"2821eb8\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-c7a0925 elementor-align-center elementor-widget elementor-widget-button\" data-id=\"c7a0925\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/myknowledgehub.org\/index.php\/evb_home\/modules_theory\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Back to Theory Modules<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Chapter 3.2 Nervous System in Vertebrates (Fishes to Mammals) A. Brain, Spinal Cord and Peripheral Nerves Introduction Definition and Basic FunctionsThe nervous system is a highly specialized network responsible for: i) Sensory Input (detecting environmental stimuli), ii) Integration (processing information in the brain and spinal cord), and iii) Motor Output (coordinating muscle and gland responses). &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"https:\/\/myknowledgehub.org\/index.php\/evb_home\/modules_theory\/chapter_3_2\/\"> <span class=\"screen-reader-text\">EVB Chapter_3_2<\/span> Read More &raquo;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2437,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"no-sidebar","site-content-layout":"page-builder","ast-site-content-layout":"full-width-container","site-content-style":"unboxed","site-sidebar-style":"unboxed","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"disabled","ast-breadcrumbs-content":"","ast-featured-img":"disabled","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","footnotes":""},"class_list":["post-2609","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/pages\/2609","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/comments?post=2609"}],"version-history":[{"count":16,"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/pages\/2609\/revisions"}],"predecessor-version":[{"id":2672,"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/pages\/2609\/revisions\/2672"}],"up":[{"embeddable":true,"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/pages\/2437"}],"wp:attachment":[{"href":"https:\/\/myknowledgehub.org\/index.php\/wp-json\/wp\/v2\/media?parent=2609"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}