Special Senses- Vision and Eye - Students PDF

Special Senses: Vision and Eye Course Learning Objective Special Senses: Identify micro- and macroscopic structures involved in the special senses using virtual microscopy, 2-D, and 3-D images to link these processes to the larger nervous system. ...

Special Senses: Vision and Eye Course Learning Objective Special Senses: Identify micro- and macroscopic structures involved in the special senses using virtual microscopy, 2-D, and 3-D images to link these processes to the larger nervous system.  Lecture Learning Objectives 1. Recall the function and the components (ID ) 5. Trace the autonomic innervation of the eye of the extraocular structures covered in this to associated muscles, linking this lecture. What role does the conjunctiva play? information to the autonomic nervous What structures are involved in tear system lecture material (responses, production and flow? sympathetic pathway) 2. Link the extraocular muscles to their actions 6. Recall the spaces of the eye and describe and identify their innervation. Recall which the importance, formation, and flow of movements test each muscle/nerve. intraocular fluid 3. List the nerves that provide innervation to 7. Draw out or write a narrative regarding the the eye and extraocular structures. List they visual pathway; identify the visual fields type of innervation they carry (somatic and portion of retinal signal carried in each sensory/motor). structure (optic nerve, chiasm, tract) 4. Describe the organization of the eyeball, 8. Trace the development of the eye focusing including on the origin of each structure A. The structural components of each layer 9. Visually identify structures of the eye B. Characteristics of structures when listed histology Extraocular Anatomy 7 EOM w in orbit extrinsic Internal i was nose control mumt of eyeball sup eyelid IifiihferatIfnn jiif targeting.ie superior rectus 4 eye hunt Depression impff inferior oblique superior 121 backoforbi g from commapusterfingysring ringoffibrousTsurr.opticcanal att.toscleraanteriorly attachment straight M'shavedirectpathfromorigin levator palpebrae superioris superioreyelidmumt Tevatorofuppereyelid Ef.ir Es EEYe Eritret MM ievaormpaiiesratsuperio.is Gom lesserwingofsphenoidbone supEf.ro Etufcinnerv bysns tabtttopsY.frhehtnicifpEatt I elevateuppereyelid innerv byCNIII oculomotor  LO1 Primary Accessory Visual Structures Eyelids Conjunctiva (mucous membrane) Lacrimal apparatus tears interim Extraocular muscles mumt Nerves CNS Gray’s Basic Anatomy (2018), Drake et al.  LO1 Eyelid Function: Movable folds that cover eye anteriorly, protect from injury and excessive light, spread lacrimal fluid A Help form “wall” between internal and external environment Superior and inferior tarsus conn T Medial and lateral palpebral ligament Orbital septum conttarsus Levator palbebrae superioris muscle and tendon (raise upper eyelid) Palpebral fissure- space created by upper and lower eyelids to Gray’s Basic Anatomy (2018), Drake et al.  LO1 Conjunctiva Conjunctiva Transparent mucous membrane that covers internal aspect of eyelid and is continuous with sclera (white of eye) mucous Function- Containcreate goblet cell that lubricate the eye; contain blood vessels that supply sclera; innervation that aids in foreign object identification Superior and inferior conjunctival fornices 0 Pockets formed by conjunctiva contactlense lost pockets Conjunctival sac open anteriorly at palpebral fissure when eyes are open Sup. conjunctival fornix Inf. conjunctival fornix  LO1 Lacrimal Apparatus Function- Produce lacrimal fluid CNVII (tears) to cleanse and lubricate eye Flow of tears 1. Lacrimal gland Produces tears 2. Excretory ducts of lacrimal gland 3. Lacrimal canaliculi cannals 4. Lacrimal sac drainintosac 5. Nasolacrimal duct 6. Nasal cavity lacrimalfluid thefts Gray’s Basic Anatomy (2018), Drake et al. duct Extraocular Eye Muscles  LO 2 Extraocular Muscles 6 Levator palpebrae superioris elevateeyelid Common tendinous ring circ conn TwhereM's att Superior rectus Lateral rectus Abduct Medial Inferior rectus Medial rectus athletemum Superior oblique rotate Inferior oblique Superior view of orbit Gray’s Basic Anatomy (2018), Drake et al.  LO 2 Extraocular Muscles ID pic manual of eye mostsuperficial All Common tendinous ring Superior rectus Lateral rectus Inferior rectus CNI Medial rectus Superior oblique Inferior oblique Levator palpebrae superioris  LO2 Extraocular Muscles Whenheadturns to (primary action) eyegaptates Superior rectus Primarily elevates Adducts Medial/internal rotation (intorsion) Medial rectus- adduct trudsmidline Inferior rectus- Y Primarily depresses Adduct X Lateral/external rotation (extorsion) Lateral rectus- abduct abducens CNVI Gray’s Basic Anatomy (2018), Drake et al.  LO2 Extraocular Muscles (primary action) Superior oblique Primary medial/internal rotation Sup Inf Abducts and depresses Recti Inferior oblique- E Primarily lateral/external rotation Abducts and elevates Infant Levator palpebrae superioris- elevate superior eyelid Gray’s Basic Anatomy (2018), Drake et al.  Extraocular M's SUPERIOR ppl do not extor CNS muscle 1 20 30 they intort internallyrotate Extrinsic Action Action Action Oblique m's rotateeye ou Futomotor Leeches Adduction Abduct ABaucent Abduction VI teeth Futomotor speeds elevates EfE Abduction LR650483 Futomotor Energies Depression Effath Adduction Teraterontregie rectus oblique CNVI CNIV Iv Trochlear Superior oblique Itself Depresses Abduction Futomotor EYE Elevates Abduction obtain Testing superior Cns Leye Fte MEOMS Rectus isolate I Efate silent midline Lateral m's Efate 1 Lateral so 1 APeh.it Left Rectus Lookmedially Closemedial I V recti Superior 1 Inferior Depress Oblique Inferior LookDown 1 Rectus Reye superior Inferior 1 rectus oblique reins Etiate silent Lateral I midline jitate heist Beta apatite l l l l Inferior 1 Inferior supterior Depress pectus oblique Innervation  LO 2 and 3 Somatic Motor Innervation drooping CN III (oculomotor) CN IV bratperior CN IV nucleus CN III nucleus Superior, inferior, medial rectus CN III Inferior oblique otrochen splits Midbrain Levator palpebrae superioris CN IV (trochlear) Pons gang Superior oblique ciliary CN VI nucleus Medulla CN VI (abducent) Lateral rectus CN VI recti  LO2 It test Gray’s Basic Anatomy (2018), Drake et al.  LO2 Testing CN with Extraocular Muscles CN? Act on the X axis Gray’s Basic Anatomy (2018), Drake et al.  LO2 Testing CN with Extraocular Muscles maintain CN? IO Why? Nose SR Both muscles act on Y axis to elevate the eye Must isolate muscle actions to test function First orient eye with the gaze of the orbit Then orient the gaze of the eye with the long fibers of the muscle (or vector)  LO2 Testing CN with Extraocular Muscles medially own recti meditative End snatrechthalcens CNIThe Superior oblique test? careathian Inferior rectus test? it P up  For context only, not exam material What is this position isolating? What is this position isolating? Gray’s Basic Anatomy (2018), Drake et al.  LO 3 Somatic Sensory Innervation Eden Ophthalmic nerve (V1) Frontal nerve- somatic sensory for extraocular structures (e.x., conjunctive and eyelid) Nasociliary nerve- somatic sensory to eye (and nasal cavity) Lacrimal nerve- somatic sensory to lateral extraocular structures Gray’s Basic Anatomy (2018), Drake et al.  LO 3 and 5 Autonomic Innervation Eyeball needed Oculomotor nerve (III) rest fight segglose Parasympathetic innervation- pupil constriction and lens accommodation via short ciliary nerves From CN VII Where does sympathetic innervation to the eye come from? CN Superior cervical ganglion -> cephalic arterial branch -> carotid plexus -> long ciliary nerves Extraocular Facial nerve (VII) Parasympathetic motor to lacrimal gland (will then travel within ophthalmic branch to lacrimal nerve) Superior cervical ganglia of sympathetic trunk Sympathetic motor to lacrimal gland from From superior superior cervical ganglia in sympathetic trunk, will travel with parasympathetic fibers cervical ganglia Gray’s Basic Anatomy (2018), Drake et al. Eye Anatomy cushion adipose  LO 4 Organization of the Eyeball jelli shape Three layers comprised of specific structures Fibrous tunic tough Vascular tunic imp nutrientsguy Inner layer EEY Masses Gray’s Basic Anatomy (2018), Drake et al.  2 LO 4 Fibrous Tunic- Shape and Resistance 1. Sclera (posterior 5/6) white Nearly avascular 1 2. Cornea (anterior 1/6) Completely avascular O Receives nutrients from peripheral capillaries, lacrimal fluid (externally), and aqueous humor (internally) Sensory innervation via ophthalmic branch of CN _____? V  LO 4 Vascular Tunic Choroid Thin, highly vascularized layer comprising the majority of the vascular tunic (5/6) fluid Ciliary body ciliaryMeolens allargyed Continuous with anterior border of choroid Lens parasum Transparent, suspended in light path Iris Colored part of eye continuous with ciliary body Pupil Diameter determined by about of light falling on photosensitive ganglion cells sum Gray’s Basic Anatomy (2018), Drake et al.  LO 4 Vascular Tunic detached necrosis 4 2 1. Choroid 5 2. Ciliary body 3 3. Iris 2 4. Pupil 1 5. Lens  LO 4 and 5 Vascular Tunic Ciliary body Ring-like thickening of vascular layer Connects anterior border of choroid to iris Ciliary muscle- control thickness of lens via suspensory ligaments (zonular fibers) Ciliary processes- secrete aqueous humor Gray’s Basic Anatomy (2018), Drake et al.  LO 4 and 5 Lens Accommodation Ciliary muscle and suspensory ligaments sphincter when A. Muscle relaxed = ligaments taut- Lens is flattened, distant objects in focus B. Muscle contracted = ligaments relaxed- Lens rounded, close objects in focus Nolte’s The Human Brain, 2021, Vanderah  LO4 and 5 Vascular Tunic Iris Superficial to lens Thin contractile diaphragm with central aperture, the pupil Contains pupil (aperture), sphincter pupillae, and dilator pupillae Gray’s Basic Anatomy (2018), Drake et al.  LO 4 Inner Layer Retina- sensory neural layer of the eye Optic part- sensitive to light Neural layer thick Multilayered and light receptive Location of ganglion cells (sensory neurons) for CN II outsidebrainstem Pigmented layer Single layer of cells that reinforce light-absorbency of choroid; reduces light scatter can'treach Nonvisal retina ant light Continuation of pigmented layer anteriorly+ supporting cells Extends over ciliary body and posterior surface of iris to pupil margin Junquiera’s Basic Histology- 2018- Mescher  LO 4 Inner Layer Retina cons Optic disc rods Entrance for CN II (optic) and associated vessels Blind spot Macula lutea (macula of retina) Small oval area of retina with special photoreceptor cones frentralis specialized for acuity of vision Fovea centralis located at very post center- area of most acute vision  LO 4 and 6 Spaces of the Eye and Humor Production Maintenance of Intraocular pressure cavity post glaucoma /Canal of Schlemm cores manents nasalcavity Anterior cavity- filled with aqueous humor IFnd sec Anterior chamber (between cornea and iris/pupil) than Posterior chamber care (between iris/pupil and lens/ciliary body) Posterior cavity- filled with vitreous humor Junquiera’s Basic Histology- 2018- Mescher Visual Pathway  1 LO 7 VISUAL temporal nasal temporal Vision Pathway Fields L R L R Temporal iiiiiaxiiiiwanimia.am 1. Retina (nasal or temporal half) Image is inverted due to lens 2. Optic nerve, travels through optic canal ipsilateral CNI 3. Optic chiasm TeMporal Ocross 4. Optic tract to brain as 5. Lateral geniculate nucleus of thalamus 6. Optic radiation 7 1 MG 7. Occipital lobe’s visual cortex ai  Visual Pathway Normal visual Fields Temporal Nasal Temporal L Retina w R OpticNerve Optic Chiasm Optic Tract synapses Lat Gen Nucleus w in Thalamus Optic Radiations r visual cortex occipital Lobe  Visual Pathway Deficits VisualFields Temporal Napaltemporalpom L retina w R OpticNerve pamage OpticNerve CNI opticchiasm Anopsia visually OpticTract Damage if catherine Blindness of R opticRadiations ipsilateraleye on 11 Horses visual Fields Mral Nasal temporalms L Retina w R OpticNerve Damage chiasm opticchiasm canalsobecaused Bitemporal Hemianopsia ma Ypiffitary.ge OpticTract Hypotham ftp tiara of Damagetobotheyesdtcrossing opticRadiations 11 Bchias.nl Horses  visual Fields temporalNashffTemporal Normal L Retina w R I OpticNerve opticchiasm optic Tract Homonymous Hemianopsia at catherina Eg she OpticRadiations 9h contralateraldamageslipchiasm crossing in Y FtYobe visual Fields TemporalNasal Temporal Normal L retina R I OpticNerve opticchiasm OpticTract Superior Quadrantanopia catharanti Eg off TTT OpticRadiations r f contralateral damage.to branchofoptic ugrior Tone  visual Fields w in Retina macula lutea fine specializedcentralacuity Temporal Nasal Temporal win fiea inighresolutionsight L w retina as a Ee.si aeision macula opticNerve fovea f ofganglioncells 17 optic chiasm visual cortexProcessing Info from macula May Have Double Optic Tract Bloodsupply Lat9 amtY Explainswhy Macula's y central vision is preserved in macularsparing optic Radiations sup r a You p Normal 1 Macular Sparing Macular Degeneration Tunnelvision seen w glaucoma hardto sleepdeprivation stimulant drug halfyinga ymjiÉt upheres seen in DMretinopathy 1111191199  LO 7 Vision Pathway Schematic diagram illustrating the formation of the optic chiasm and tracts. All information from the temporal side of a vertical line passing through a given fovea enters the ipsilateral optic tract; all information from the nasal side T Nasal Tempora crosses in the chiasm and enters the contralateral optic tract. The result, as indicated, is that each optic tract “looks at” the contralateral visual field. Thalamus Nolte’s The Human Brain, 2021, Vanderah  Nolte’s The Human Brain, 2021, Vanderah LO 7 Vision Pathway chiasm MTeep tooptic gland tumor pit crosses ein JEEmm o inC l A e Tegtatietina B O Ñitr Domes crossed Retinavision TemporalRetina  Nolte’s The Human Brain, 2021, Vanderah LO 7 Vision Pathway * deep to is optic pituitary gland chiasm ↳ Pitullary timous cause R. erse's can Nasal field vision 07 vision changes R eyes. temporal of field vision R L temporal temporal refina nasal nasal reting refina refina · cut optic newve A C B pressure/ · optic damage to midline of chiasm optic chiasm D e lateral will impact vision of aspect both eyes optic tract danage Development of the Eye  LO 8 Development of the Eye Begins in 4th week of development organogenesis VÉE Tauch From the developing brain Optic vesicles extend from developing diencephalon – will become retina Optic cup will form on anterior surface indentation Fathers Connected to developing brain via optic stalk- will enclose optic vessels From ectoderm and mesenchyme Lens- overlying ectoderm forms lens pit Sclera and choroid- mesenchyme around optic cup Choroid will form iris, ciliary body, and suspensory ligaments Eyelids, conjunctiva, Eomtconn. l and cornea- surrounding mesenchyme and ectoderm external The primary vitreous body will form in optic cup; form vitreous humor Eye Histology  LO 9 A 1 Bcornea sclera Eye Histology MEET 1. Fibrous tunic A. Cornea B. Sclera Iris 2. Vascular tunic II I. Lens 4 I III II. Iris III. Pupil ephin a 3. Anterior cavity a. Anterior chamber Ant b. Posterior chamber Postb 3 4. Posterior cavity Eatin  LO 9 1. Sclera nonvisthinner 2. Choroid 3. Retina a. Pigmented layer b. Neural layer A. Retinal ganglionic cells poor sclerd my b 1 2 thing a retino 3 A  LO 9 1 6 2 5 lens Ghmber Plin 7 c post iris front chamber a 1. Lens 3 floc 2. Iris 3. Ciliary body cil.tn antavity a. Ciliary processes b 4 b. Ciliary muscle c. Suspensory ligaments 4. Anterior cavity 5. Posterior cavity 6. Anterior chamber 7. Posterior chamber