Chapter 15: Special Senses

Chapter 15:Special Senses

Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn

Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.

(a)(b)

(c)

(d)

Fungiformpapillae

Taste bud

Circumvallate papilla

Epiglottis

Palatine tonsil

Foliatepapillae

Lingual tonsil Basal cell

Taste fibersof cranialnerve

Connective tissue

Gustatoryreceptorcells

Tastepore

Gustatoryhair

Stratifiedsquamousepitheliumof tongue

Gustatory (taste) cells Tastepore

Connective tissue

Basal cells

Figure 15.23: Location and structure of taste buds on the tongue, p. 581.



Figure 15.24: The gustatory pathway, p. 583.

Gustatorycortex(in insula)

Thalamicnucleus(ventralposteriormedialnucleus)

Pons

Solitary nucleusin medulla oblongata

Facialnerve (VII)

Glosso-pharyngealnerve (IX)

Vagus(nerve X)



Figure 5.21: Olfactory receptors, p. 579.

Mitral cell

Olfactorygland

Olfactorytract

Olfactoryepithelium

Filaments of olfactory nerve

Cribriform plateof ethmoid bone

Lamina propria connective tissue

Basal cell

Supporting cell

Dendrite

Olfactory cilia

Glomeruli

Axon

Olfactory receptorcell

Mucus

Route of inhaledair containing odormolecules

Frontal lobeof cerebrum

Nasalconchae

Route ofinhaled air

Olfactoryepithelium

Olfactory tractOlfactorybulb



Figure 5.22: Olfactory transduction process, p. 580.

GolfReceptor

Extracellular fluid

Cytoplasm

Odorant Adenylate cyclase

Na+

Ca2+

GTP

GTP GTP

GDP cAMP

cAMP

ATP

1

2 34

5

George Wald 1906 – 1997 received the Nobel Prize in 1967 for discoveries concerning the primary physiological and chemical visual

processes in the eye



Figure 15.1a: The eye and associated accessory structures, p. 557.

(a)

Eyelashes

Sclera(covered byconjunctiva)

Site whereconjunctivamerges withcornea

Lateralcommissure(canthus)

Iris

Medialcommissure(canthus)

Lacrimalcaruncle

Eyelid

Eyelid

Eyebrow

PupilPalpebralfissure



Figure 15.1b: The eye and associated accessory structures, p. 557.

(b)

Levator palpebraesuperioris muscle

Orbicularisoculi muscleEyebrow

Tarsal plate

PalpebralconjunctivaTarsalglands

Cornea

Palpebralfissure

Eyelashes

Bulbarconjunctiva

Conjunctivalsac

Orbicularisoculi muscle



Figure 15.2: The lacrimal apparatus, p. 558.

Lacrimal sacLacrimalgland

Excretory ductsof lacrimal gland

Lacrimal punctum

Lacrimal canaliculus

Nasolacrimal duct

Inferior meatusof nasal cavity

Nostril



Figure 15.3: Extrinsic eye muscles, p. 559.

(a) (b)

(c)

Opticnerve

Inferiorrectusmuscle

Inferiorobliquemuscle

Superior oblique muscle

Annular ring

Trochlea

Superior oblique tendon

Superior rectus muscle

Lateral rectus muscle

Conjunctiva

Axis atcenterof eye

Medialrectus muscle

Inferiorrectus muscle

Lateralrectus muscle

Lateral rectusMedial rectusSuperior rectusInferior rectusInferior obliqueSuperior oblique

Name Action

Moves eye laterallyMoves eye mediallyElevates eye and turns it mediallyDepresses eye and turns it mediallyElevates eye and turns it laterallyDepresses eye and turns it laterally

VI (abducens)III (oculomotor)III (oculomotor)III (oculomotor)III (oculomotor)IV (trochlear)

Controlling cranialnerve



Figure 15.4a: Internal structure of the eye (sagittal section), p. 560.

(a)

Ora serrata

Ciliary body

Ciliary zonule(suspensoryligament)

Cornea

Iris

Anteriorpole

Pupil

Anteriorsegment(cavity)

Lens

Scleral venous sinus(Canal of Schlemm)

Posterior segment (cavity) (contains vitreous humor)

Optic nerve

Posterior pole

Fovea centralis

Macula lutea

Retina

Choroid

Sclera

Central arteryand vein of the retina

Optic disc(blind spot)



Figure 15.6b: Microscopic anatomy of the retina, p. 562.

(b)

Neural layerof retina

Pigmentedlayer ofretina

Centralarteryand veinof retina

Opticnerve

Sclera

Choroid

Optic disc



Figure 15.6a: Microscopic anatomy of the retina, p. 562.

(a)

Amacrine cell

Horizontalcell

RodCone

Pigmentedlayer of retina

Bipolarcells

Ganglioncells

Pathwayof light



Figure 15.13: Focusing for distant and close vision, p. 567.

(a) Lens is flattened for distant vision

(b) Lens bulges for close vision

(c) Anterior segment viewed from behind

Lens

Invertedimage

Ciliary zonule

Ciliary muscle

Nearly parallel raysfrom distant object

Sympathetic +

Divergent raysfrom close object

Invertedimage

Parasympathetic +

Ciliary muscle

Lens

Ciliary zonule(suspensory ligaments)



Figure 15.15: Photoreceptors of the retina, p. 570.

Process ofbipolar cell

Outerfiber

Apical microvillus

Discs containingvisual pigments

Inn

er s

egm

ent

Melaningranules

Pigment cellnucleus

Innerfibers

Rod cellbody

Cone cellbody

SynapticterminalsRod cellbody

Nuclei

Mitochondria

Connectingcilia

Ou

ter

seg

men

t

Pig

men

ted

lay

er

Basal lamina(border with choroid)

Retinal

Opsin

Discs beingphagocytized

(a)

(b)Li

ght

Lig

ht

Lig

ht



Figure 5.19: Visual fields of the eyes and visual pathway to the brain, inferior view, p. 576.

(a) (b)

Pretectalnucleus

Right eye Left eye

Fixationpoint

Opticradiation

Superiorcolliculus(sectioned)

Lateralgeniculatebody

Optic tractOptic chiasma

Uncrossed (ipsilateral) fiberCrossed (contralateral) fiber

Optic nerve

Lateral geniculatebody of thalamus

Superior colliculusOccipital lobe (visual cortex) Corpus callosum

Supra-chiasmaticnucleus



Figure 15.25a: Structure of the ear, p. 584.

(a)

External(outer) ear Middle

ear

Internal(inner) ear(labryinth)

Pharyngotympanic(auditory) tube

Externalacousticmeatus

Auricle(pinna)

Helix

Lobule

Tympanic membrane



Figure 15.25b: Structure of the ear, p. 584.

(b)

Pharyngotympanic(auditory) tube

Auditoryossicles

Entrance to mastoid antrum in the epitympanic recess

Tympanicmembrane

Semicircularcanals

Cochlea

Cochlearnerve

Vestibularnerve

Oval window(deep to stapes)

Round window

Incus(anvil)

Malleus(hammer)

Stapes(stirrup)

Internaljugular vein

Vestibule

Externalacousticmeatus



Figure 5.26: The three auditory ossicles in the right middle ear, p. 585.

Pharyngotym-panic tube

Tensortympanimuscle

Tympanicmembrane(medial view)

Stapes

Malleus

Superior

Anterior

Incus Epitympanic recess

Stapediusmuscle



• Anterior

Semicircular ducts insemicircular canals:

• Posterior

• Lateral

Cristae ampullaresin the ampullae

Utricle in vestibule

Saccule in vestibule

Stapes inoval window

Temporalbone

Facial nerve

Vestibular nerve

Superior vestibular ganglion

Inferior vestibular ganglion

Cochlear nerve

Maculae

Spiral organ (of Corti)

Cochlear duct in cochlea

Round window

Figure 5.27: Membranous labyrinth of the internal ear, p. 586.



Figure 5.29: Sound: source and propagation, p. 589.

(a) (b)

(c)

Area ofcompressedmolecules

Crest

Trough

Time Amplitude

Area ofrarefaction

Wavelength

Air

pre

ssu

re



Figure 15.31: Route of sound waves through the ear, p. 590.

Fluids in cochlear canals

Upper and middle

Internal earExternal ear

PinnaExternalacousticmeatus

Air

Tympanicmembrane

Malleus, incus,stapes

(ossicles)

Ovalwindow Lower

Middle ear

Onevibration

TimeSpiral organ

(of Corti)stimulated

Amplificationin middle ear

Amplitude

Pre

ssu

re



Figure 15.35: Structure of a macula, p. 594.

Macula ofutricle

Macula ofsaccule

Otoliths

Hair bundle

KinociliumStereocilia Otolithic

membrane

Vestibularnerve fibers

Hair cells

Supportingcells



Figure 15.36: The effect of gravitational pull on a macula receptor cell in the utricle, p. 595.

Otolithicmembrane

Kinocilium

Stereocilia

Receptorpotential

Nerveimpulsesgenerated investibular fiber

Depolarization

(Hairs bent towarkinocilium)

dHyperpolarization

(Hairs bent awayfrom kinocilium)

Increasedimpulse frequency

Excitation

Decreasedimpulse frequency

Inhibition



Figure 15.37: Location and sturcture of a crista ampullaris, p. 596.

(a)

(c) (d)

(b)

Cupula Cupula at rest

Position of cupuladuring turn

Turning motion

Fluid motion inducts

Afferent fibers of vestibular nerve

Increased firing Decreased firing

Position of cupuladuring turn

Ampulla of left ear

Ampulla ofright ear

Horizontal ducts

Flow ofendolymph

Cupula

Cristaampullaris

Fibers ofvestibular nerve



Figure 15.38: Pathways of the balance and orientation system, p. 597.

Input

Central nervoussystem processing

Output

Oculomotor control(cranial nerve nucleiIII, IV, VI)(eye movements)

Spinal motor control(cranial nerve nuclei XIand vestibulospinal tracts)(neck movements)

Vestibularreceptors

Visualreceptors

CerebellumVestibularnuclearcomplex

Reticularnuclei

Somaticreceptors

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Chapter 15: Special Senses