PHIS 206 Lecture 6 Spring 2025 PDF
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Uploaded by ExquisiteErudition5802
2025
Anderson
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Summary
This lecture covers the Central Nervous System (CNS), including its organization, subdivisions (like the somatic and autonomic nervous systems), key players (neurons and glia), protection (meninges, cerebrospinal fluid, blood-brain barrier), and structures like the cerebral cortex, basal nuclei, thalamus, hypothalamus, cerebellum, and brain stem. The lecture also touches upon different pathways and organization in the spinal cord.
Full Transcript
Physiology 206 Lecture 6 - CNS Anderson CNS Nutshell FuzzForm Image License Organization Central Nervous System - (CNS) Brain and Spinal Cord Peripheral Nervous System - (PNS) Nerve fibers that travel from the periphery to the CNS → (afferent division) Nerve fibers that travel fr...
Physiology 206 Lecture 6 - CNS Anderson CNS Nutshell FuzzForm Image License Organization Central Nervous System - (CNS) Brain and Spinal Cord Peripheral Nervous System - (PNS) Nerve fibers that travel from the periphery to the CNS → (afferent division) Nerve fibers that travel from the CNS to the periphery → (efferent division) Enteric Nervous System (ENS) Controls muscular activity and secretions of digestive organs Efferent Division Breakdown Somatic Nervous System Also known as somatic motor system → controls skeletal muscle movement Autonomic Nervous System - ANS Also known as visceral motor system → controls activity of smooth muscle of organs, cardiac muscle of heart, and glands ANS breakdown Two divisions Sympathetic Nervous System → fight or flight Parasympathetic Nervous System → rest and digest (or feed and breed) (ANS also has some overlying control of ENS) Players Neuron - Nerve cell - Nerve fiber → somewhat synonymous Classes of Neurons Afferent → to CNS Efferent → from CNS Interneurons → within CNS Glia Glial cells (Astrocytes, Oligodendrocytes, Schwann Cells, Microglia, Ependymal Cells) provide physical, metabolic, and functional support to neurons Basic Network Nascari and Sved Image License Everybody OpenStax Image License Protection and Nourishment Protective Mechanisms Cranium/Vertebral Column Meninges Cerebrospinal Fluid (CSF) Blood-Brain Barrier (BBB) OpenStax Image License Meninges Membrane wrapping Dura mater Arachnoid mater Pia mater OpenStax Image License CSF Specialized blood vessels create a fluid (cerebrospinal fluid - CSF) that bathes and cushions the brain and spinal cord OpenStax Image License Blood-Brain Barrier Blood vessels that feed the brain also protect it → Blood-Brain Barrier ”Feet” of Astrocytes form continuous barrier along outside of capillaries within brain tissue Sykepleiepluss.com Image License Cerebral Cortex Left/Right Hemispheres (connected by corpus callosum) Outer gray matter Inner white matter Jkwchui Image License Lobes Frontal Lobe Motor Activity Speaking Expression of ”Thinking” Personality Parietal Lobe Sensory Reception (General Senses) Jkwchui Image License Sensory Processing (Includes Special Senses) More Lobes Occipital Lobe Vision Sensory Processing Temporal Lobe Hearing Sensory Processing Jkwchui Image License Some emotion Localization BruceBlaus Image License Phineas Gage Story/Controversy Frontal Lobe Injury Changes the science? Or just poor coping? Homunculus Mapping Area of cortex allotted to body parts varies... What areas are allotted more sensory cortex? Btarski Image License Homunculus Mapping Area of cortex allotted to body parts varies... What areas are allotted more motor cortex? [email protected] Image License Basal Nuclei/Basal Ganglia Important for ”automatic” motor functions Help modify motor programs Parkinson’s Dz BruceBlaus Image License Thalamus/Hypothalamus Thalamus is primary relay station for sensory input Hypothalamus important for homeostatic functions, endocrine organs OpenStax Image License Limbic system Collection of structures Governs basic emotions Primal behaviors Pharmaceutical Target Antidepressant Medications Recreational Drugs BruceBlaus Image License Cerebellum Smoothing things Compares intended motion with actual motion, offers corrections (synergy) OpenStax Image License Brain Stem Components Medulla Pons Midbrain Reticular Activating System Spreads throughout brain stem Manipulation of sensory information, sends it to the thalamus Awareness OpenStax Image License Target of ADHD meds Spinal Cord user:debivort OpenStax Image License Image License Spinal cord organization Pathways to and from the cord have dedicated structures (roots) The white matter within the cord is divided into tracts for information transfer BruceBlaus Image License Neurons in the cord - Gray and White Matter Gray because nothing is myelinated here → mostly cell bodies in gray matter horns The myelinated axons are in the white matter tracts BruceBlaus Image License Tracts Notice how the names of the tracts often describe their direction and origin/destination Polarlys and Mikael Häggström Image License
