Download Free Medical Sensory Systems PowerPoint Presentation

Sensory Systems PowerPoint Presentation

DOWNLOAD MEDICAL POWERPOINT PRESENTATION

About This Presentation

Description : Check out this medical PowerPoint presentation titled "SENSORY SYSTEMS".

This medical PowerPoint presentation is about the sensory systems, responsible for detecting, processing, and interpreting sensory information from the environment. These systems include:

Visual system: responsible for processing visual information from the eyes, including color, shape, and movement.
Auditory system: responsible for processing sound waves from the ears, including pitch, volume, and location of the sound source.
Gustatory system: responsible for processing taste information from the tongue, including sweet, sour, salty, and bitter.
Olfactory system: responsible for processing smell information from the nose, including the identification of different odors.
Somatosensory system: responsible for processing touch, pressure, temperature, and pain sensations from the skin, muscles, and internal organs.

These sensory systems work together to provide us with a comprehensive understanding of our environment and to help us interact with it effectively. The information gathered by these systems is transmitted to the brain, where it is processed and integrated to produce our perceptual experiences.

Tags : sensory systems, Visual system, Auditory system, Gustatory system, Olfactory system, Somatosensory system

Published on : Jun 23, 2023 | Views : 913 | Downloads : 3

Shareable Url :

Embed Code :

Comment

Transcript

Slide 1-

CHAPTER 3SENSORY SYSTEMS
Slide 2-

Disorders of sensory systems Deficits Sensory organ Sensory nerves Central nervous system Hyperactivity Central neuropathic pain Tinnitus Tingling Normal response that is redirected Pain from touch Dizziness and vertigo from head movements
Slide 3-

Disorders of sensory systems Reduced sensitivity Hearing loss Visual impairment Incorrect response Hyperacusis Distorted sounds Allodynia Hyperpathia
Slide 4-

Disorders of sensory systems Impaired conduction of the physical stimulus to the receptors Impaired function of receptors Impaired function of sensory nerves Impaired or changed function of the central nervous system
Slide 5-

Reduced sensitivity Often caused by disorders of the sense organs Injury to afferent nerves
Slide 6-

Hyperactive sensory disorders Increased sensation of physical stimuli Altered sensation of physical stimuli Sensation without any physical stimulation
Slide 7-

General organization of sensory systems Conduction of the physical stimulus to the receptors Sensory receptors Sensory nerves Central nervous system
Slide 8-

Sensory transduction A physical stimulus generates a receptor potential The receptor potential is a graded potential The receptor potential is conducted electrotonically to the spike generation site
Slide 9-

Bipolar receptor cells (taste)
Slide 10-

Initiation of nerve impulses Occurs at the first node of Ranvier
Slide 11-

Two different types of receptors, with bipolar nerve fibers
Slide 12-

Sensory transduction (mechanoreceptor in a muscle)
Slide 13-

Central nervous system
Slide 14-

HUMAN Mouse Chick
Slide 15-

Auditory nervous system Ascending auditory pathways From: Møller, 2005
Slide 16-

Two different ascending sensory pathways have been identified: The classical systems The non-classical systems
Slide 17-

From: Møller: Sensory Systems, 2003 Classical auditory pathways Non-classical auditory pathways
Slide 18-

Non-classical auditory pathways Receive input from the somatosensory system Use the dorsal part of the MGB From: Møller, 2005
Slide 19-

The classical ascending pathways The number of nuclei is different in different sensory systems Use ventral thalamic nuclei that project to primary sensory cortices Neurons processes only input from of one sensory modality
Slide 20-

From: Møller, 2005 Visual system Classical ascending pathways Non-classical ascending pathways
Slide 21-

The nonclassical pathways Use dorsal and medial thalamic nuclei that project to secondary cortices and to other parts of the CNS Receive input from more than one sense
Slide 22-

Somatosensory pathways Classical pathways Non-classical pathways From: Møller, 2005
Slide 23-

ppt slide no 23 content not found
Slide 24-

Processing after primary sensory cortices Integration of input from different sensory systems occurs in association cortices Parallel processing Stream segregation
Slide 25-

The neocortex has six layers
Slide 26-

Simplified diagram of the connections to and from the different layers of the cerebral cortex From: Møller: Sensory Systems, 2002
Slide 27-

Maps Tonotopic Somatotopic
Slide 28-

SURFACE VIEW
Slide 29-

LOWER BODY IS REPRE-SENTED NEAR THE MIDLINE
Slide 30-

Tonotopic organization in the CN of a cat, as an example of tonotopic organization in the auditory system
Slide 31-

ppt slide no 31 content not found
Slide 32-

Tonotopic organization in the CN of a cat, as an example of tonotopic organization in the auditory system
Slide 33-

Parallel processingStream segregation
Slide 34-

Parallel processing: Cochlear nucleus
Slide 35-

Function of sensory nervous systems Processing of sensory input at the peripheral level Convergence (spatial integration) Interplay between inhibition and excitation
Slide 36-

Spatial integration: Receptive field of a dorsal column nucleus cell
Slide 37-

Convergence of input to a secondary neuron
Slide 38-

Lateral inhibition
Slide 39-

Central processing of sensory information Each stage enhances or suppress specific Information
Slide 40-

Parallel processing:The same information is processed in different structuresStream segregation:Different kinds of information is processed in different structures(“What” and “Where”)
Slide 41-

Processing after primary sensory cortices Integration of input from different sensory systems occurs in association cortices
Slide 42-

From: Møller: Sensory Systems, 2003 Stream segregation Cortical circuitry Dorsal stream “where” Ventral stream “what”
Slide 43-

Sensory information can reach other regions than sensory regions Motor systems Memory Emotional brain (limbic system)
Slide 44-

From: Møller, 2005 Two different routes to the Amygdala from a sensory system
Slide 45-

From: Møller: Sensory Systems, 2003 Connections from a sensory system to the amygdala “the high route”
Slide 46-

Connections from a sensory system to the amygdala “the low route” From: Møller: Sensory Systems, 2003
Slide 47-

From: Møller: Sensory Systems, 2003 Connections from the amygdala
Slide 48-

Hypoactive sensory disorders Loss of sensitivity Hearing loss Poor vision Numbness Loss of vestibular (balance) function
Slide 49-

ppt slide no 49 content not found
Slide 50-

HEARING LEVEL AT 4 kHz NOISE IMMISSION LEVEL
Slide 51-

Courtesy of M. Charles Liberman Genetic, epigenetic and environmental Causes (and a stochastic component ?)
Slide 52-

Age-related hearing loss
Slide 53-

Normal variations in hearing loss of 70 year old individuals
Slide 54-

Variations in speech discrimination in 70 year old individuals
Slide 55-

Hearing loss in Ménière's disease
Slide 56-

Effect of surgical injuries to the auditory nerve: Large decrease in speech discrimination
Slide 57-

Hyperactive sensory disorders Tinnitus Paresthesia Phosphenes Phantom sensations Central neuropathic pain
Slide 58-

Subjective and objective tinnitus Different forms of tinnitus have very different effects on an individual’s life
Slide 59-

Similarities between chronic pain and severe tinnitus
Slide 60-

There are many forms of tinnitus Mild tinnitus: Does not interfere noticeably with everyday life Moderate tinnitus: May cause some annoyance and may be perceived as unpleasant Severe tinnitus: Affects a person’s entire life in major ways Patients’ own perception varies between mild, moderate and severe (disabling)
Slide 61-

Important to have words for disorders We cannot think about matters that do not have names The same words is used to describe very different forms of tinnitus and pain Using the same names for fundamentally different disorders is a disadvantage in treating these disorders
Slide 62-

How prevalent is severe tinnitus? Some statistics show 50 million people have tinnitus in the USA The prevalence of severe (bothersome) tinnitus is infrequent at young age; it reaches 12-14% for people at age 65 according to one study
Slide 63-

How prevalent is severe pain? Some pain was reported by 86% of individuals above the age of 65 (Iowa study, 1994) The prevalence of severe pain was 33% for people at age 77 and above (Swedish study, 1996)
Slide 64-

Severe tinnitus affects a person’s entire life in major ways Prevents or disturbs sleep Interferes with or prevents Intellectual work Often accompanied by altered perception of sound
Slide 65-

Severe pain affects a person’s entire life in major ways Prevent or disturb sleep Interfere with or prevents intellectual work May cause suicide May involve limbic structures causing affective reactions Often accompanied by abnormal sensations from touch
Slide 66-

Severe tinnitus is often accompanied by altered perception of sound Sounds are distorted Sounds have exaggerated loudness (hyperacusis) Sounds are unpleasant Sounds are painful and arouse fear (phonophobia)
Slide 67-

Little is known about the cause of subjective tinnitus Noise exposure Ototoxic antibiotic Acoustic tumors
Slide 68-

The sympathetic nervous system is involved in some forms of severe tinnitus Some forms of tinnitus can be cured by sympathectomy
Slide 69-

Deprivation of sound can cause changes in neural processing such as change in temporal integration Expression of neural plasticity
Slide 70-

The anatomical location of the abnormality that cause chronic pain and tinnitus may be different from that to which the pain or the tinnitus is referred
Slide 71-

The abnormal neural activity that causes symptoms are not generated at the location where the symptoms are felt Examples: Phantom pain Tinnitus with severed auditory nerve
Slide 72-

The tinnitus in some patients can be modulated by stimulation of the somatosensory systems (such as by electrical stimulation of the median nerve)“cross-modal” interaction
Slide 73-

Non-classical auditory pathways Receive input from the somatosensory system Use the dorsal part of the MGB From: Møller, 2005
Slide 74-

Other signs of involvement of the somatosensory system Gaze related tinnitus Neck muscles and tinnitus TMJ and tinnitus Sensation of sound from touching the skin
Slide 75-

Connections between spinal C2 segment and the dorsal cochlear nucleus Can explain why electrical stimulation of the skin behind the ears can modulate tinnitus
Slide 76-

Symptoms and signs of neuropathic pain and severe tinnitus Strong emotional components Depression High risk of suicide
Slide 77-

Severe tinnitus is often associated with affective (mood) disorders Depression Phonophobia
Slide 78-

The amygdala is involved in fear and other mood disorders
Slide 79-

Connections from the auditory system to the amygdala Cortical-cortical connections (the “high route”) Subcortical connections (the “low route”)
Slide 80-

From: Møller, 2005
Slide 81-

CONCLUSION ACTIVATION OF NON-CLASSICAL ASCENDING SENSORY PATHWAYS CAN CAUSE SYMPTOMS AND SIGNS OF SEVERAL DISEASES
Slide 82-

Neural plasticity play greater role in generating symptoms and signs than previously assumed Plastic changes are reversible Treatments without medicine and surgery may alleviate pain and tinnitus
Slide 83-

Therapy There is no treatment for tinnitus that is comparative to common pharmacological treatment of pain. Treatment of tinnitus has been mainly benzodiazepines (GABAA agonists)
Slide 84-

Reversal of neural plasticity “TENS” (transderm electric nerve stimulation) has been used for many years in treatment of chronic pain Recently sound stimulation in various forms have been introduced in treatment of severe tinnitus
Slide 85-

Stimulation of somatosensory system can relieve tinnitus Electrical stimulation of the ear and of the skin behind the ears have been used to treat tinnitus Electrical stimulation of the auditory cortex is in a stage of development Few systematic studies of efficacy have been published
Slide 86-

ppt slide no 86 content not found