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    Autonomic Nervous System-1

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    The document discusses the autonomic nervous system. It defines the somatic and autonomic nervous systems, and describes the divisions of the autonomic system - the sympathetic and parasympathetic nervous systems. It explains the neuronal arrangement in the autonomic nervous system, including the pathways, ganglia, and neurotransmitters involved. It also discusses Horner's syndrome, which results from interruption of the sympathetic nerve supply to the head and neck.

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    Autonomic Nervous System-1

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    33 views46 pages
    The document discusses the autonomic nervous system. It defines the somatic and autonomic nervous systems, and describes the divisions of the autonomic system - the sympathetic and parasympathetic nervous systems. It explains the neuronal arrangement in the autonomic nervous system, including the pathways, ganglia, and neurotransmitters involved. It also discusses Horner's syndrome, which results from interruption of the sympathetic nerve supply to the head and neck.

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    The document discusses the autonomic nervous system. It defines the somatic and autonomic nervous systems, and describes the divisions of the autonomic system - the sympathetic and parasympathetic nervous systems. It explains the neuronal arrangement in the autonomic nervous system, including the pathways, ganglia, and neurotransmitters involved. It also discusses Horner's syndrome, which results from interruption of the sympathetic nerve supply to the head and neck.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    33 views46 pages

    Autonomic Nervous System-1

    Uploaded by

    a-tld
    The document discusses the autonomic nervous system. It defines the somatic and autonomic nervous systems, and describes the divisions of the autonomic system - the sympathetic and parasympathetic nervous systems. It explains the neuronal arrangement in the autonomic nervous system, including the pathways, ganglia, and neurotransmitters involved. It also discusses Horner's syndrome, which results from interruption of the sympathetic nerve supply to the head and neck.

    Copyright:

    © All Rights Reserved
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    of 46

    AUTONOMIC NERVOUS

    SYSTEM
    Dr Khwaja Mohd Amir
    Objectives
    a) Identify the physiological divisions of peripheral nervous
    system (somatic & autonomic).

    b) Identify divisions of autonomic nervous system (sympathetic


    & parasympathetic) and describe the origin of both divisions.

    a) Describe the course of autonomic nerves (preganglionic &


    postganglionic) and discuss the different types of autonomic
    ganglia.

    b) Describe the actions of ANS in head and neck and relate


    these actions to manifestations of Horner’s syndrome.
    Nervous System
    Somatic and Autonomic Nervous System
    Somatic and Autonomic Nervous System
    SOMATIC NS AUTONOMIC NS
    Termination of Dorsal horn of SC Intermediolateral
    AFFERENT neuron horn of SC
    Termination of Ventral horn of SC Autonomic ganglia
    INTERNEURON/PREG
    ANGLIONIC NEURON
    EFFERENT neuron Goes to skeletal Goes to visceral
    muscles. effector
    Innervation Skeletal muscle Smooth muscle,
    cardiac muscle &
    secretory glandular
    epithelium
    Neuro transmitter Acetylcholine Ach ,Adr &NAdr
    Activity Excitation Excitation &
    Inhibition
    Voluntary Involuntary
    Functions of ANS
    Maintenance of homeostatic
    conditions of the body

    Regulation of visceral activities

    Smoothening body’s response to


    environmental changes
    Coordination of body’s responses
    to exercise and stress
    Assisting the endocrine system to
    regulate reproductive functions
    General Organization Of The Autonomic Nervous
    System
    I. Autonomic areas in the cerebral hemispheres
    1. Higher brain centre- limbic cortex
    2. Hypothalamus- integration of somatic, autonomic and endocrine
    functions

    II. Autonomic areas in the brainstem


    1. Autonomic centers in the reticular formation
    2. General visceral afferent nucleus- nucleus of solitary tract
    3. General visceral efferent nuclei-(give origin to preganglionic fibres of
    cranial parasympathetic outflow)
    a) Edinger Westphal Nucleus-mid brain
    b) Salivary nucleus (Superior and inferior)-pons
    c) Dorsal nucleus of vagus-medulla
    III. Autonomic centers in the Spinal Cord- intermediolateral grey column
    1. Thoracolumbar outflow (T1-L2)- preganglionic sympathetic NS
    2. Craniosacral Outflow (S2-S3)-preganglionic parasympathetic NS

    IV. Peripheral part of ANS-


    All autonomic nerves and ganglia throughout the body
    In fact all autonomic fibres are intimately related to different cranial and
    spinal nerves
    Neuronal Arrangement in ANS
    Neuronal Arrangement in ANS
    Sympathetic And Parasympathetic Nervous System
    Sympathetic And Parasympathetic Nervous System
    Sympathetic NS Parasympathetic NS

    Outflow Thoracolumbar division Craniosacral division


    Cranial- III,VII,IX,X
    Sacral-S 2-4

    Preganglionic neuron Short & myelinated Long & myelinated

    Postganglionic neuron Long & unmyelinated Short & myelinated

    Activity Spread over many Localized-single organ


    segment or organ system
    Action Fight or flight Rest and digest
    “Catabolic NS” “Anabolic NS”
    Neurotransmitter Pre gang-Ach Pre gang-Ach
    Post gang- NA Post gang- Ach
    SYMPATHETIC NEVOUS SYSTEM
    • Fate of preganglionic sympathetic neurons

    Thoracolumbar
    (T1-L2)

    Preganglionic
    neuron in
    Paravertebral
    ganglia

    Pass thru and Pass thru and


    Travel up or
    Synapse synapse with synapse with
    down &
    pre- vertebral adrenal
    synapse there
    ganglia medulla
    Sympathetic Ganglia

    Spinal cord

    Sympathetic ganglia

    Prevertebral/Collateral Peripheral/terminal
    Paravertebral ganglia ganglia
    ganglia
    Cervical-sup, middle, Within or close to the
    Celiac
    inf structures-heart, bronchi,
    Sup mesentric
    Thoracic-11-12 pancreas
    Inf mesentric
    Lumbar-4
    Sympathetic Ganglia
    Postganglionic Sympathetic Neuron

    Through spinal nerve

    Through cranial nerve

    Through a vascular branch

    Through autonomic plexus enter a vicera


    Nerve connections among
    the spinal cord, spinal
    nerves, sympathetic
    chain, and peripheral
    sympathetic nerves
    Superior cervical ganglia
    • Close to base skull, of C2-3
    • Innervates structures in the head-
    dilator pupillae,Muller’s muscle,
    lacrimal and salivary gland.
    • Fibres travel in Perivascular plexus
    along carotid arteries.
    • Affected individuals- ophtalmic signs

    Middle and inferior cervical ganglion


    • Innervates structures in the chest-
    trachea, esophagus, heart and lungs
    • Often inferior and first thoracic ganglion
    fuse to form stellate ganglion
    Thoracic Ganglia

    • 12
    • Supply mainly thoracic structures
    • T1-T2: head and neck
    • T3-T4:thoracic viscera
    • T5-T6:upper limb
    • T7-T12:abdominal viscera

    Lumbar and Sacral Ganglia


    • T10-L1:lower limbs
    • L1-L2: abdominal viscera
    Prevertebral/collateral
    ganglia

    Terminal ganglia
    Prevertebral Ganglion
    • Also k/a Collateral ganglion
    • 3- named after arteries they overlie
    • Celiac ganglion-T5-T12:stomach, SI, liver, pancreas , GB, spleen and
    kidneys
    • Sup mesenteric ganglion;-T10-T12: SI &LI
    • Inf mesenteric ganglion;-L1-L3: lower colon, rectum, ur bladders & repr
    organs

    Terminal ganglia
    • Located in the organs innervated by the sympathetic fibres
    Adrenal Medulla

    • Neuroendocrine structure
    • Modified sympathetic
    ganglion (chromaffin cell)-
    • Pregang fibres from lower
    thoracic seg that travel in
    lesser splanchnic nerve
    • Chromaffin cells are like post
    ganglionic neurons that have
    lost their axons- synthesise Epi
    & Nepi
    • Act as peripheral amplifier
    PARA- SYMPATHETIC NERVOUS SYSTEM

    Digestion Defecation

    PARA- SYMPATHETIC
    NERVOUS SYSTEM(4D)

    Dull Diuresis
    Parasympathetic NS

    • Cranio
    sacral
    outflow
    Autonomic Neurotransmitters

    Sympathetic fibres Parasympathetic fibres


    Ø Preganglionic-Ach Ø Preganglionic-Ach
    Ø Post-ganglionic-Ach
    Ø Post-ganglionic-
    Adrenergic: Nepi (mainly)
    or Epi.All except
    cholinergic ones

    Cholinergic-Ach. Sweat
    gland, blood vessels in
    heart and skeletal muscles
    Autonomic neurotransmitters
    Receptors in ANS
    Effects of ANS
    Effects of ANS
    Region Sympathetic activity Parasympathetic
    activity
    Skin • Becomes pale-Activation of • Generalized
    α-1 R. on blood vessels Sweating
    • Localised Sweating
    • Hairs-Stand up due to
    contraction of arector
    pili(α-1R)

    Eyes • Dilator pupillae (α-1R )- • Constrictor pupillae-


    mydriasis miosis
    • Ciliary muscles (β-2 R) • Ciliary muscles
    relaxes- far vision contracts-near vision
    Horner’s syndrome
    Horner’s syndrome

    A condition of occulo-sympathetic paralysis

    Commonly occurs in Clinical features are due to


    • Malignancy of cervical “Interruption of sympathetic nerve
    lymph nosed supply to the head and neck”
    • Pancoast tumour of lungs

    “pressing the cervical First neuron


    • Reticulospinal tract
    sympathetic chain” leison

    Second
    • Thoracic SC gray matter
    neuron leison
    Leison may be at following levels
    Third neuron
    • Cervicothoracic ganglion
    leison
    Clinical Features

    • Unopposed action of sphincter


    Miosis
    pupillae

    • Paralysis of levator palpabrae


    Ptosis
    supirioris

    • Dryness of one half of face due


    Anhydrosis to impaired secretion of sweat
    glands

    • Same half of face due to loss of


    Flushing/blanching vasoconstrictor effect on skin

    • Enophthalmus
    • Loss of ciliospinal reflex
    Important causes of Horner’s
    syndrome
    Summary
    a) Identify the physiological divisions of peripheral nervous
    system (somatic & autonomic).

    b) Identify divisions of autonomic nervous system (sympathetic


    & parasympathetic) and describe the origin of both divisions.

    a) Describe the course of autonomic nerves (preganglionic &


    postganglionic) and discuss the different types of autonomic
    ganglia.

    b) Describe the actions of ANS in head and neck and relate


    these actions to manifestations of Horner’s syndrome.
    THANKS

    & GUYTON & HALL Textbook of Medical Physiology, 14th edition,


    page: 763-775

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