Chapter 10Chapter 10

(1)

Dee Unglaub Silverthorn, Ph.D.

H ^UMAN P ^HYSIOLOGY H ^UMAN P ^HYSIOLOGY

PowerPoint

^®

Lecture Slide Presentation by

Dr. Howard D. Booth, Professor of Biology, Eastern Michigan University

AN INTEGRATED APPROACH

T H I R D E D I T I O N

Chapter 10 Chapter 10

Sensory Physiology

(2)

About this Chapter About this Chapter

• What are the senses

• How sensory systems work

• Body sensors and homeostatic maintenance

• Sensing the external environment

• Mechanisms and pathways to perception

(3)

• Stimulus

• Internal

• External

• Energy source

• Receptors

• Sense organs

• Transducer

• Afferent pathway

• CNS integration

General Properties of Sensory Systems

(4)

The Human

Brain

(5)

General Properties of Sensory Systems General Properties of Sensory Systems

Figure 10-4: Sensory pathways

(6)

• Simple receptors

• Complex neural

• Special senses

• Chemoreceptors

• Mechanoreceptors

• Thermoreceptors

• Photoreceptors

Sensory Receptor Types

(7)

Sensory Receptor Types Sensory Receptor Types

Figure 10-1: Sensory receptors

(8)

The Cerebral Cortex The Cerebral Cortex

• Three kinds of functional areas

• Motor areas

• Sensory areas

• Association areas

(9)

Association Areas Association Areas

• Association cortex : Essential for mental functions that are more complex than detecting basic dimensions of sensory

stimulation, for which primary sensory areas appear to be

necessary. In humans the association areas are by far the most developed part of the cerebral cortex, and the brain in general.

These areas are necessary for perceptual activities, like

recognizing objects (toasters, horses, trees, words, etc), rather than simple contours, edges or sensory qualities like color or pitch.

• Each sensory system has its own association areas on the cerebral cortex. The sensory systems (vision, hearing,

etc.) each have their own primary area on the cortex, which

gets the most direct connections from its sense. Each primary

sensory area sends information to its own cortical association

areas, which are next to their primary areas

(10)

Functional and Structural Areas of the Cerebral Cortex

Functional and Structural Areas of the Cerebral

Cortex

(11)

Functional and Structural Areas of the Cerebral Cortex

Figure 13.11b

(12)

• Vision

• Hearing

• Taste

• Smell

• Equilibrium

Special Senses – External Stimuli

(13)

Special Senses – External Stimuli Special Senses – External Stimuli

Figure 10-4: Sensory pathways

(14)

Sensory Areas – Sensory Homunculus Sensory Areas – Sensory Homunculus

Figure 13.10

(15)

Inc., publishing as Benjamin Cummings

Motor Homunculus Motor Homunculus

Figure 13.10

(16)

Homunculus

(17)

• Touch

• Temperature

• Pain

• Itch

• Proprioception

• Pathway

Somatic Senses – Internal Stimuli Somatic Senses – Internal Stimuli

Figure 10-10: The somatosensory cortex

(18)

• Receptor

• Threshold

• Action potential

• Sensory neurons

• Primary – medulla

• Secondary – thalamus

• Tertiary – cortex

• Integration

• Receptive field

• Multiple levels Somatic Pathways

Somatic Pathways

(19)

Somatic Pathways Somatic Pathways

Figure 10-9: Sensory pathways cross the body’s midline

(20)

• Location

• Lateral inhibition

• Receptive field

• Intensity

• Duration

• Tonic receptors

• Phasic receptors

• Adaptation

Sensory Modality

(21)

• Mechanoreceptors

• Free nerve endings

• Pacinian corpuscles

• Ruffini corpuscles

• Merkel receptors

• Meissner's corpuscles

• Baroreceptors

Touch (pressure)

(22)

Touch (pressure) Touch (pressure)

Figure 10-11: Touch-pressure receptors

(23)

• Free nerve endings

• Cold receptors

• Warm receptors

• Pain receptors

• Sensory coding:

• Intensity

• Duration

Temperature

(24)

Temperature Temperature

Figure 10-7: Sensory coding for stimulus intensity and duration

(25)

• Nocioceptors

• Reflexive path

• Itch

• Fast pain

• Slow pain

Pain and Itching

(26)

Pathways of Itch from Skin to Brain.

Yosipovitch G, Bernhard JD. N Engl J Med 2013;368:1625-1634.

(27)

Gate Control Theory of Pain Gate Control Theory of Pain

Figure 10-12: The gate control theory of pain modulation

(28)

• Ischemia

• Other visceral pain

• Modulation

• Thalamus

• Gate control

• Magnification

• Analgesic drugs

• Aspirin

• Opiates Pain

Pain

(29)

Referred Pain Referred Pain

Figure 10-13: Referred pain

(30)

• Olfactory cell

• Chemoreceptor- Humans have about 350 different types of odorant receptors,

Mice 1200

• Olfactory cilia

• Olfactory bulb

• Olfactory nerve

• CNS integration

• Amygdala

• Hippocampus

• Olfactory

Olfactor: Sense of Smell

(31)

Olfactor: Sense of Smell Olfactor: Sense of Smell

Figure 10-14a, b: ANATOMY SUMMARY: Olfaction

(32)

Olfactor: Sense of Smell Olfactor: Sense of Smell

Figure 10-14c: ANATOMY SUMMARY: Olfaction

(33)

• 5 Tastes

• Taste buds

• Taste cells

• Mechanism

• Transduction

• Integration

• Thalamus

• Gustatory cortex

• "Specific hunger"

Taste: Chemoreceptors Taste: Chemoreceptors

Figure 10-16: Summary of taste transduction

(34)

• Sound waves

• Conduction

• Air

• Bone

• Fluid

• Membranes

• To hair cell

Hearing: Mechanoreceptors

(35)

(36)

Hearing: Mechanoreceptors Hearing: Mechanoreceptors

Figure 10-19: Sound transmission through the ear

(37)

(38)

(39)

• Fluid wave moves

• Tectoral membrane

• Steriocilia move

• Ion channels open

• Depolarization

• NT release

• Sensory nerve AP

Hearing: Hair Cell Transduction

(40)

Hearing: Hair Cell Transduction Hearing: Hair Cell Transduction

Figure 10-20: The cochlea

(41)

Hearing: Hair Cell Transduction Hearing: Hair Cell Transduction

Figure 10-21: Signal transduction in hair cells

(42)

• Pitch

• Intensity

• Localization

• Integration

• Medulla

• Thalamus

• Auditory cortex

• Deafness

• Conductive

• Sensorineural

Hearing: Integration and Problems Hearing: Integration and Problems

Figure 10-5: Localization of sound

(43)

Hearing: Integration and Problems Hearing: Integration and Problems

Figure 10-22: Sensory coding for pitch

(44)

• Body balance

• Body position

• Body movement

• Propioceptors

• Vision

• Vestibular apparatus

Equilibrium: Mechanoreceptor

(45)

• Integration

• Medulla

• Cerebellum

• Thalamus

• Cortex

Equilibrium: Mechanoreceptor Equilibrium: Mechanoreceptor

Figure 10-26: Central nervous system pathways for equilibrium

(46)

• Otolith organs

• Gravity

• Calcite crystals

• Hair cells

• Semicircular canals

• Endolymph Fluid moves which stimulates Each Crista which consists of:

Cupula

Embedded Hair cells: activate CN VIII

Equilibrium: Vestibular Apparatus

(47)

Semicircular Canals of the Vestibular Apparatus Semicircular Canals of the Vestibular Apparatus

• Have Posterior, Horizontal and Superior Semicircular Canals

• They sense Rotational Acceleration in various directions

• The Cristae within the Ampula (enlarged chamber at the end of each canal) are the sensory receptors

• Endolymph moves the gelatinous cupula with the hair cells embedded in it and

stimulates vestibulocochlear nerve (CN

VIII)

(48)

Equilibrium: Vestibular Apparatus Equilibrium: Vestibular Apparatus

Figure 10-23a, b: ANATOMY SUMMARY: Vestibular Apparatus

(49)

Otolith Organs of the Vestibular Apparatus Otolith Organs of the Vestibular Apparatus

• Otolith Organs of the Utricle and Saccule Sense Linear Acceleration and Head

Position

• They are arranged horizontally (Utricle-if head tips back gravity causes othliths to slide) and vertically (Saccule-senses

vertical forces such as an elevator dropping)

• Macula are the sensory receptors of the utricle and saccule

• Otoliths are crystals that move in response

to gravitational forces

(50)

Equilibrium: Vestibular Apparatus Equilibrium: Vestibular Apparatus

Figure 10-23c, d: ANATOMY SUMMARY: Vestibular Apparatus

(51)

• Reflected light translated into mental image

• Pupil limits light, lens focuses light

• Retinal rods and cones are photoreceptors Vision: Photoreceptors

Vision: Photoreceptors

Figure 10-36: Photoreceptors in the fovea

(52)

(53)

Cataract

(54)

(55)

(56)

Retina (Right Eye)

(57)

Retina (Left Eye)

(58)

Hypercholesterolemia Hypercholesterolemia

• Accumulations of lipids leak from surrounding

capillaries and

microaneuryisms,

they may form a

circinate pattern.

(59)

Hypertension

(60)

Proliferative diabetic retinopathy

(61)

Panretinal laser photocoagulation

(62)

• Rods – night vision

• Cones – color & details

• Bipolar & ganglion cells converge, integrate APs

Photoreception and Local Integration

(63)

Photoreception and Local Integration Photoreception and Local Integration

Figure 10-35: ANATOMY SUMMARY: The Retina

(64)

• Rod cells: monochromatic

• Cone cells: red, green, & blue

• Discs: visual pigments

• Pigmented epithelium

• Melanin granules

• Prevents reflection Retina: More Detail

Retina: More Detail

(65)

Retina: More Detail Retina: More Detail

Figure 10-38: Photoreceptors: rods and cones

(66)

• Photons "bleach" opsin, retinal released, cascade, Na ⁺ channel closes, K ⁺ opens , hyperpolarization

• Reduces NT release Phototransduction

Phototransduction

(67)

Phototransduction Phototransduction

Figure 10-40: Phototransduction in rods

(68)

• Bipolar

• Ganglion

• Movement

• Color

• Optic nerve

• Optic chiasm

• Optic tract

• Thalamus

• Visual cortex

Vision: Integration of Signals to Perception Vision: Integration of Signals to Perception

Figure 10-29b, c: Neural pathways for vision and the papillary reflex

(69)

(70)

(71)

(72)

• Sensory pathway: receptor, sensory neuron(s) & CNS

• Somatic senses: touch, temperature, pain

& proprioception communicate body information to CNS

• Special senses: taste, smell, hearing, equilibrium, & vision

• Outside conditions for CNS integration into perception

• Receptors transduce mechanical, chemical or photon energy into GPs then to APs

Summary

Chapter 10Chapter 10

Dee Unglaub Silverthorn, Ph.D.

H UMAN P HYSIOLOGY H UMAN P HYSIOLOGY

PowerPoint

Lecture Slide Presentation by

Dr. Howard D. Booth, Professor of Biology, Eastern Michigan University

AN INTEGRATED APPROACH

T H I R D E D I T I O N

Chapter 10 Chapter 10

Sensory Physiology

About this Chapter About this Chapter

• What are the senses

• How sensory systems work

• Body sensors and homeostatic maintenance

• Sensing the external environment

• Mechanisms and pathways to perception

• Stimulus

• Internal

• External

• Energy source

• Receptors

• Sense organs

• Transducer

• Afferent pathway

• CNS integration

General Properties of Sensory Systems

General Properties of Sensory Systems

The Human

Brain

General Properties of Sensory Systems General Properties of Sensory Systems

Figure 10-4: Sensory pathways

• Simple receptors

• Complex neural

• Special senses

• Chemoreceptors

• Mechanoreceptors

• Thermoreceptors

• Photoreceptors

Sensory Receptor Types

Sensory Receptor Types

Sensory Receptor Types Sensory Receptor Types

Figure 10-1: Sensory receptors

The Cerebral Cortex The Cerebral Cortex

• Three kinds of functional areas

• Motor areas

• Sensory areas

• Association areas

Association Areas Association Areas

• Association cortex : Essential for mental functions that are more complex than detecting basic dimensions of sensory

stimulation, for which primary sensory areas appear to be

necessary. In humans the association areas are by far the most developed part of the cerebral cortex, and the brain in general.

These areas are necessary for perceptual activities, like

recognizing objects (toasters, horses, trees, words, etc), rather than simple contours, edges or sensory qualities like color or pitch.

• Each sensory system has its own association areas on the cerebral cortex. The sensory systems (vision, hearing,

etc.) each have their own primary area on the cortex, which

gets the most direct connections from its sense. Each primary

sensory area sends information to its own cortical association

areas, which are next to their primary areas

Functional and Structural Areas of the Cerebral Cortex

Functional and Structural Areas of the Cerebral

Cortex

Functional and Structural Areas of the Cerebral Cortex

Functional and Structural Areas of the Cerebral Cortex

Figure 13.11b

• Vision

• Hearing

• Taste

• Smell

• Equilibrium

Special Senses – External Stimuli

Special Senses – External Stimuli

Special Senses – External Stimuli Special Senses – External Stimuli

Figure 10-4: Sensory pathways

Sensory Areas – Sensory Homunculus Sensory Areas – Sensory Homunculus

Figure 13.10

Motor Homunculus Motor Homunculus

Figure 13.10

Homunculus

Homunculus

• Touch

H ^UMAN P ^HYSIOLOGY H ^UMAN P ^HYSIOLOGY