感觉器官解剖生理课件.pptVIP

Part V The sensory organs Chapter one The visual organ consists of eyeball and accessory organs of eye. Section one the Eyeball 一、The structure of eyeball The eyeball comprises the wall of the eyeball and the contents enclosed by it． (一) The Wall of Eyeball It consists of three tunics(layers)， from outside inwards， which are the fibrous tunic，the vascular tunic and retina． 1 The fibrous tunic(outer supporting layer) consists of the sclera behind and the cornea in front. 1) The sclera a. features: posterior five-sixths of the outer layer . strong , white and opaque b. scleral venous sinus (Schlemm’ canal) 2) The cornea a. features: anterior one-sixth of the outer layer. transparent and non-vascular, but rich nerve terminals 2. The vascular tunic consists of the iris, the ciliary body and the choroid 1) The iris a. location and shape b. pupil c. sphincter and dilator pupillae d. iridocorneal angle e. colour : brown , dark , blue .depends upon the number and placement of pigment cells (melanocytes) 2) The ciliary body a.location and shape b.ciliary ring and ciliary processes c.ciliary muscle d.ciliary zonule(suspensory ligament) e.function: produce aqueous humor 3) The choroid a.location and shape : posterior two thirds of choroid b. features : numerous blood vessels and pigment cells 3. The inner tunic (the retina) 1) Division: the optic part, ciliary part and iridial part 2)Construction: two layers →outer pigmented layer and inner neuroretina(photoreceptors: rod and cone cells) 3) Optic disc (blind spot) 4) Macula lutea : fovea centralis→vision is sharpest （二） The contents of the eyeball include the aqueous humor, the vitreous body and the lens .With the cornea altogether to form the refractive media. l. The chambers of the eye : between the cornea and the lens; and divided into the anterior and the posterior chambers by the iris .It is filled with aqueous humor. 2. The aqueous humor : produ