3: The Central Nervous System

Essentials of Physiology for Nurse Anesthetists (Gopalan) · LibreTexts

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    From LibreTexts, under CC BY-NC-SA 4.0, as the source states it; its equations are written in TeX, which the PDF shows typeset. This page at LibreTexts.

    • 3.1: Objectives
      This page discusses the development, anatomy, and functions of the brain and spinal cord, focusing on protective coverings, cerebrospinal fluid, and blood supply. Key brain structures include the cerebral cortex, basal nuclei, and limbic system, along with mechanisms for blood flow regulation. It explains language processing, memory formation, spinal cord organization, and sensory/motor pathways, detailing reflexes and their brain connections.
    • 3.2: Introduction
      This page discusses the central nervous system (CNS), highlighting its reliance on a continuous blood supply for energy due to neurons' inability to store glucose. It emphasizes the importance of oxygen for the CNS's function and notes the cardiovascular system's reflexive response to maintain blood flow to the brain in the event of an oxygen deficiency.
    • 3.3: Embryonic Development of the Brain and Spinal Cord
      This page outlines the early development of the embryonic nervous system, starting around three weeks with the formation of the neural plate and subsequent neural tube. This tube segments into three primary vesicles: prosencephalon, mesencephalon, and rhombencephalon, which further specialize into five regions, including the telencephalon and diencephalon from the prosencephalon, and the metencephalon and myelencephalon from the rhombencephalon.
    • 3.4: Protective Coverings of the Brain and Spinal Cord
      This page discusses the meninges, the protective membranes surrounding the brain and spinal cord, comprised of three layers: the dura mater, arachnoid mater, and pia mater. The dura mater is the tough outer layer, the arachnoid mater is the delicate middle layer that aids in cerebrospinal fluid circulation, and the pia mater closely adheres to the brain, providing nutrients through its blood vessels. Together, these layers provide critical protection and support for the central nervous system.
    • 3.5: The Ventricles and the Central Canal
      This page describes the dynamics of cerebrospinal fluid (CSF) within the brain's four ventricles, derived from the embryonic neural tube. It explains the connections among the lateral, third, and fourth ventricles, including the pathways for CSF flow and exit. CSF circulates around the brain and spinal cord, ultimately returning to the bloodstream through arachnoid granulations.
    • 3.6: Cerebrospinal Fluid
      This page explains the role of choroid plexuses in producing cerebrospinal fluid (CSF), which circulates 100-150 ml in the central nervous system. CSF is essential for neuronal function and has distinct electrolyte concentrations and a pH of about 7.3, influencing respiratory regulation. Additionally, CSF provides protection and waste removal by circulating from the ventricles to the subarachnoid space and being reabsorbed into the venous system through arachnoid granulations.
    • 3.7: Blood Supply to the Brain
      This page explains the brain's substantial need for blood flow, consuming 15-20% of cardiac output to meet its metabolic demands. Blood supply is primarily from the internal carotid and vertebral arteries, forming the circle of Willis for collateral circulation, while drainage occurs through dural sinuses into the jugular veins.
    • 3.8: The Brain
      This page summarizes the organization and functions of various brain regions, including the cerebral cortex, basal nuclei, limbic system, and diencephalon, with a focus on their roles in sensory processing, motor control, language, emotions, and memory. It discusses lateralization of brain functions, highlights the brain's adaptability after trauma, and details the autonomic nervous system and brainstem's critical functions in regulating bodily processes and coordinating movements.
    • 3.9: Memory
      This page discusses the case of Henry Molaison (HM), whose lobectomy for epilepsy led to anterograde amnesia. His condition highlighted the crucial role of the temporal lobe and hippocampus in memory formation, revealing the distinction between short-term and long-term memories. It underscores that long-term potentiation (LTP) enhances synaptic efficiency, which is essential for converting short-term memories into long-term storage.
    • 3.10: Sleep
      This page discusses the nature of sleep as a physiological state with altered consciousness and reduced sensory activity, emphasizing its role in neuron rest and emotional functioning. It details the five stages of sleep, including REM, and notes their alignment with circadian rhythms. Additionally, it highlights insomnia as a sleep disorder characterized by difficulties in initiating or maintaining sleep, often influenced by stress and lifestyle.
    • 3.11: The Spinal Cord
      This page explores the spinal cord's structure and development within the central nervous system (CNS), detailing its protective meninges and the classification of spinal nerves. It also covers the organization of nerve root fibers and ganglia, including the unipolar nature of dorsal root ganglion cells and the positioning of sympathetic chain ganglia in the autonomic nervous system.
    • 3.12: Nerves
      This page discusses the organization and functions of the peripheral nervous system (PNS), detailing the structure of nerves and their protective layers. It highlights the roles of cranial and spinal nerves in sensory and motor functions, the pathways of motor neuron axons, and the importance of dermatomes and myotomes in diagnosing neurological and motor control issues.
    • 3.13: Reflexes
      This page covers somatic reflexes like the stretch reflex, Golgi tendon reflex, and flexor withdrawal reflex, explaining their mechanisms and functions. It describes sensory pathways such as the spinothalamic pathway, responsible for pain and temperature detection.
    • 3.14: References
      This page provides an extensive collection of references on the embryology, anatomy, and physiology of the central and peripheral nervous systems. It covers development stages, blood supply, cerebrospinal fluid, brain mapping, cranial nerves, and reflex arcs, among other topics. The references include academic citations from sources like StatPearls and OpenStax, and feature figures and illustrations to aid comprehension. The materials reflect recent advancements in neuroanatomy from 2016 to 2024.

    This page titled 3: The Central Nervous System was last modified on Thu, 13 Mar 2025 22:10:30 GMT and is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Chaya Gopalan (Consortium of Academic and Research Libraries in Illinois (CARLI)) .