Nervous System: IV

Somatic SensoryReflexesNeural IntegrationANS

Nervous System Design Sensory Receptors in PNS

Somatic: Tactile, Nocireceptors, Proprioceptors, Baroreceptors

Special: Photoreceptors, Mechanoreceptors, Chemoreceptors

CNS Spinal Cord Brainstem Cerebellum Thalamus Cerebral Cortex

Motor Effectors Somatic Motor Autonomic Motor

Sensory Overview

CN: Special and Somatic Sensory

Somatic Sensory: Skin

Somatic Sensory: Proprioception

Dermatomes

Stretch Receptors

Golgi Tendon Organ

Intrafusal Fibers

Somatic Reflex Arc

Motor Response

Neuromuscular Junction

Motor End Plate

Patellar Reflex: Monosynaptic

Polysynaptic Reflexes

Somatic Reflex Tests

Spinal Cord and Spinal Nerves

PNS CNS for somatic sensory

Spinal Cord Gray and White Matter

Spinal Cord Histology Areas

Spinal Tract Names

Organization of Spinal Cord Segment

Spinal Tract Locations

Ascending Tracts: Specific

Dorsal Column – Medial Lemniscus Localized touch Gradations of touch Vibratory sensations Proprioception Pressure sensations

Fasciculus Cunneatus Upper Limbs Upper Trunk Neck

Fasciculus Gracilis Lower limbs Inferior trunk

Ascending Tracts

Dorsal White Columns

Ascending Tracts: Nonspecific Anterolateral System

Pain Temperature Crude touch Crude pressure Tickle / Itch Sexual sensations

Spinothalamic tract

Lateral Pain Temperature

Anterior Crude Touch Crude Pressure

Spinothalamic Tracts

Localization of information: Spinal Nerve Input to Spinothalamic tract

Spinocerebellar Pathways

Posterior Cerebellar Trunk, lower limb proprioceptors Tendon stretch Ascend on same side to inferior cerebellar

peduncle Anterior Cerebellar

Trunk, lower limb proprioceptors Tendon stretch Ascend and cross twice to anterior cerebellar

peduncle

Spinocerebellar Tracts

Somatosensory Reflexes

Descending Motor Tracts Direct / Pyramidal

Skeletal voluntary motor Corticobulbar

CN motor Corticospinal

Lateral Cross in medulla

Anterior Cross in spinal cord

Indirect / Extrapyramidal Tectospinal

Coordinate reflexes to visual and auditory stimulus

Vestibulospinal Muscle tone to extensors Posture and balance

Rubrospinal Muscle tone to flexors

Reticulospinal (A, M, L) Visceral motor tone Visceral motor functions Visceral reflexes

Descending Motor Tract Locations

Ventral White Matter

Ventral White Axons leaving Gray Matter

Descending Motor Tract Functions

Corticospinal Tract Location

Corticospinal General Descending Pathway

Descending Somatic Pathway

Extra Pyramidal Tracts

Motor Tracts Compared

Basal Nuclei Adjust movement

Preparation Coordinate

Rhythmic Cycles Subconscious control Alter motor commands

Communication In

Caudate Putamen

Out Globus Pallidus Thalamus

Basal Nuclei Afferents

Caudate and Putamen

Basal Nuclei Efferents

Globus pallidus to Thalamus

Basal Nuclei Regulation Summary

Thalamic Nuclei: Ventrolateral Group

Thalamus: Ventral Group

Thalamus: Dorsolateral

Thalamus: Dorsomedial Group

Thalamus: Anterior Group

Thalamus: Pulvinar

Thalamus: Geniculates

Lateral Geniculate

Medial Geniculate

Problems

Spinal Nerve Rupture

Spinal Cord Tracts and related problems

Nervous System Organization: ANS

CNS and PNS for ANS

Somatic vs. Autonomic

Spinal Nerve Review

Pathways and Reflexes Compared for SNS and ANS

Lateral Gray Horn of Spinal Cord

ANS Divisions

Origins for Preganglionic ANS neurons

Postganglionic Neuron Pathways

Myelination vs Nonmyelination

ANS Motor

Preganglionic ANS neurons

Neuron Organization : Preganglionic Neurons, NT, and Receptors

Sympathetic NS

Lateral Gray Matter: ANS sensory and motor for Sympathetic Division

Sympathetic Chain

Sympathetic Chain Ganglia in cat

Sympathetic Chain Pathways

Thoracic Cord: Gray and White Ramus

Sympathetic Collateral Ganglia

Sympathetic Ganglion

Adrenal Medulla

Rami Communicans and Sympathetic Pathways

Ganglia Location

Parasympathetic NS

Parasympathetic Cranio-Sacral

Parasympathetic Ganglia

Parasympathetic Nerves

Cranio CN III CN VII CN IX CN X

Sacral Splanchnic N.

CN X

CN X Motor pathways

CN X: Innervation

CN X: Sensory Inputs and Pathways

Synapse and Varicosities

ANS Neurotransmitters

ANS neurotransmitter receptors

Nicotinic Receptors

Receptor Location Effect

Nicotinic ganglionic

ANS ganglions Excitatory ANS postganglionic neurons

Nicotinic Neuromuscular Junction

Neuromuscular Junction

Excitatory

Skeletal m.

Muscarinic Receptors

Receptor Location Effect

Muscarinic

M1

Sympathetic Postganglionics

Ach Inhibit NE

Relaxation of vascular Sm M.

Muscarinic

M2

Heart, Eye, GI, UG, Respiratory

Inhibitory cAMP

K+ influx

Muscarinic

M3

Vascular: dilation

Exocrine Gland secretion

PIP DAG, IP3

Catecholamine Receptors: AlphaReceptors Location Effects

Alpha 1 Constriction of Vascular SmM &

GI sphincters

Pupillary dilation

IP3/DAG Ca++

Alpha 2 Inhibits post ganglionic

Gi inhibit cAMP

Catecholamine Receptors: BetaReceptors Location Effects

Beta 1

excitatory

Heart, brain, kidney

Adenyl Cyclase cAMP

Beta 2 Inhibits Vascular & Respiratory Sm M

Excites Islet B

Adenyl Cyclase cAMP

Beta 3 Adipose cAMP

Parasympathetic Pathway Review

Cholenergic Neurotransmitters

ACh formation and recycling

Sympathetic Pathway Review

Adrenergic Neurotransmitters

Adrenergic Synapse

NT hydrolysis from Tyrosine

Enzymes in Catecholamine Formation

Catecholamine Breakdown Uptake I

Reuptake of NE into presynaptic neuron Monoamine Oxidase (MAO) breakdown

Uptake II Reuptake of NE into non-neuronal cells

Catechol-O-Methyltransferase (COMT) breakdown Glial cells Smooth Muscle

Metabolites diffuse out MAO completes breakdown

NE

MAO Blocker

Chemicals in ANS

Neurotransmitters ACh NE ATP VIP Dopamine Metenkephalin Neuropeptide-Y

Hormones Epinephrine Prostaglandins

Visceral Reflex Arc

ANS Referred Pain reflexes

Lateral Spinothalamic Pathway: Pain

Ascending Spinal Cord Tracts for ANS

Thalamic VPL input from Spinothalamic

Sensory Homonculus

Referred Pain

ANS Controls

ANS pathways for Hypothalamic Control

Medulla Oblongata Controls

ANS tests

Generalized ANS effects

Dual Innvervation

Dual Innervation Example

Dual Innervation: Salivary Glands

ANS drugs

Clinical ANS Applications

Questions?