大连医科大学：《组织胚胎学》课程教学课件（英文讲稿）15.Eye and ear

ANDEYESEARS

EYES AND EARS 1

EyeballCross Section of the EyeScleraRetinaCorneaPosteriorchamberOpticPupilLensnerveAnteriorTapetumchamberIrisCiliarybody2Extraocularmuscles

Eyeball 2

IrisRetinaVascular layerCiliary bodyChoroidWallsFibrouslayerJScleraCorneaLensContentAqueous humorVitreous body3

Retina Iris Vascular layer Ciliary body Walls Choroid Fibrous layer Sclera Cornea 3 Lens Content Aqueous humor Vitreous body

1.Fibrous tunica:a.Cornea: anterior 1/16;colorless andtransparent;5 layers.b.Sclera:posterior15/16;opaque and white;S

1. Fibrous tunica: a.Cornea: anterior 1/16; colorless and transparent; 5 layers. 4 b. Sclera: posterior 15/16; opaque and white;

*Epithelium:nonkeratinized stratifiedsquamous epi.;Mv;basal layerisevennessandremarkableregenerative capacity; nerveendings*Bowman's membrane:homogeneous;consists ofcollagen fibrils and no cells.*Stroma:makeup 90%ofthethicknessofthecornea.FibroblastAvascular.Parallel lamellae,parallel fibrils.*Descemet'smembrane:collagen fibrils. Repaired by 5endothelium

* Epithelium: nonkeratinized stratified squamous epi. ; Mv; basal layer is evenness and remarkable regenerative capacity; nerve endings * Bowman’s membrane: homogeneous; consists of 5 collagen fibrils and no cells. * Stroma: make up 90% of the thickness of the cornea. Avascular. Parallel lamellae, parallel fibrils. * Descemet’s membrane: collagen fibrils. Repaired by endothelium

Transparencyofcorneaisdueto:@cornealepitheliumisevenness.@withoutpigment cells.③avascular@the corneal epitheliumand endotheliumarecapable oftransportingsodium ions,chlorideionsand water,maintainingthecornealstromain a relatively hydrated state.regular orientationoftheverythin collagenfibrils of the stroma.6

Transparency of cornea is due to: ①corneal epithelium is evenness. ②without pigment cells. ③avascular ④the corneal epithelium and endothelium are 6 capable of transporting sodium ions, chloride ions and water, maintaining the corneal stroma in a relatively hydrated state. ⑤regular orientation of the very thin collagen fibrils of the stroma

b. Sclera: D.c.T·rich in collagen f., elastic f.fibroblasts34:lamina cribrosa·Function

7 b. Sclera : D.C.T • rich in collagen f., elastic f., fibroblasts • lamina cribrosa • Function

C.Corneal limbus:an area of transitionfromthecornea to the sclera. highly vascularized.Schlemm's canal/scleral venous sinus:drainstheaqueoushumorScleral spur: ciliary muscles attached8

8 c. Corneal limbus: an area of transition from the cornea to the sclera. highly vascularized. Schlemm’s canal/scleral venous sinus : drains the aqueous humor Scleral spur: ciliary muscles attached

PupilIris2.Vascularlayer:L.C.T, rich in b.v. &Sclerapigments.a.Iris: pupilanteriorchamber &IrisCLOSED ANGLEposteriorSchlemm'scanalchamberEpiscleralveinAqueous veinIridocornealTrabecularmeshworkangleb.Ciliary bodyc. Choroid:CiliarybodyAqueousflow

2. Vascular layer: L.C.T, rich in b.v. & pigments. a.Iris: pupil anterior chamber & 9 posterior chamber Iridocorneal angle b. Ciliary body: c. Choroid:

*Anteriorborderfurrows of irislayer:fibroblasts &melanocytes* Iris stroma: L.C.T.steliate fibroblasts& rich in b.v. &stellate melanocytespigments*Irisepithelium:anteriorlimitinglayeranteriorlayer:dilatorpupillaemargn ofbloodvesselPuplmusclesphincterpupillaestromamusclesphincter muscle80oolpupifposteriorlayer:S店dilatormusclepigmentedpigment-ladenmacrophageepitheliumfibrobiastposterior epitheluma10

* Anterior border layer: fibroblasts & melanocytes * Iris stroma: L.C.T. & rich in b.v. & pigments * Iris epithelium: anterior layer: dilator pupillae 10 muscle sphincter pupillae muscle posterior layer: pigmented epithelium