视器与位听器的组织结构 Sense organs 周俊 20180621

实验内容 目的要求：掌握眼球壁和内耳的组织结构特点 观察切片: 1.角膜 (NO.47) 2.眼球后壁(NO.48) 3.内耳(NO.49)

Ciliary body Eyeball Walls Cornea 1/6 1.Fibrous layers Sclera 5/6 Eye ball 2.Vascular layers 3.Retina: innermost layer adjacent to the vitreous body. Sclera 5/6 Choroid 2/3 Ciliary body Iris 1 2 3

Cornea(NO.47) 5 layers Corneal epithelium Anterior limiting lamina 角膜细胞（成纤维细胞） Corneal stroma posterior limiting lamina Corneal endothelium

Ultrastructure of the Corneal stroma

The back wall of the eyewall (NO.48) Sclera（巩膜） Choroid（脉络膜） Retina（视网膜）

Sclera: many different direction DCT. form bundles

Choroid Pigment cells Blood vessel

Retina（视网膜） 1.色素上皮层 2.神经层： 外核层（视杆视锥层） 内核层（双极细胞层） 节细胞层

Choroid 10 layers Retina 1 pigmented epithelium 2 layer of photoreceptors 3 external limiting membrane 4 outer nuclear layer 5 outer plexiform layer 6 inner nuclear layer 7 inner plexiform layer 8 ganglion cell layer 9 optic nerve layer 10 internal limiting membrane

Retina

视杆细胞 (Rod cell): 1）顶部膜盘脱落更新 2）感受弱光，夜视;内突小球状 视锥细胞 (Cone cell)： 1）顶部膜盘连续不脱落 2）感受强光，颜色；内突足状

Central fovea (中央凹) and Papilla of optic nerve(视神经乳头）

耳 (auricle) External ear ： auricle（耳廓） Middle ear： Mastoid process 1)auricle(pinna):oval,projects from the lateral surface of the head.Its shape is determined by internal supporting elastic cartilage. 2)an air-filled tubular space that follows a slightly S-shaped course 3)The tympanic membrane separates the external acoustic meatus from the middle ear. Middle: 1)an air-filled space, called typanic cavity, which are spanned by three small bones. 2)The auditory tube connects the middle ear to the nasopharynx. Equalizing the pressure of the middle ear with atmospheric pressure.It is common for infections to spread from pharynx to the middle ear via the auditory tube. 3)Mastoid bone is spongy bone. External ear ： auricle（耳廓） external acoustic meatus（外耳道） tympanic membrane (eardrum)（鼓膜） Middle ear： tympanic cavity（鼓室） auditory tube（咽鼓管） mastoid process（乳突小房）

Internal ear （内耳） Membranous labyrinth （膜迷路） Bony labyrinth （骨迷路） 半规管 The internal ear consists of two labyrinthine compartments, one contained within the other. The bony labyrinth is a complex system of interconnected cavities and canals in the petrous part of the temporal bone. The vestibule is small oval chamber located in the center of the bony labyrinth.The semicircular canals extend from the vestibule posteriorly, and the cochlea extends from the vestibule anteriorly. The semicircular canals are tubes within the temporal bone that lie at right angles to each other. The cochlea is a cone-shaped helix connected to the vestibule. The membraneous labyrinth consists of a series of communicating sacs and ducts containing endolymph. It is suspended within the bony labyrinth, and remaining space is filled with perilymph. Endolymph has similar composition to intracellular fluid.Perilymph similar to extracellular fluid. Bony labyrinth （骨迷路） 半规管 前庭 耳蜗 Membranous labyrinth （膜迷路） 1）膜半规管 2）椭圆囊，球囊 3）膜蜗管

Six sensory regions of the membranous labyrinth: Specialized sensory cells are located in six regions in the membranous labyrinth. 1)cristae ampullaris are located in the membranous ampullae of the semicircular ducts.They are sensitive to angular acceleration of the head. 2)Two maculae,sense the position of the head and its linear movement. 3)functions as the sound receptor. Six sensory regions of the membranous labyrinth: Three crista ampullaris （壶腹嵴） Two maculae (椭圆囊斑，球囊斑） The spiral organ of Corti (螺旋器）

The position of cochlear duct within the bony cochlea The cochlea duct divides the cochlear canal into three parallel compartment or scalae.The cochlea duct itself is the scala media. The scala vestibuli and scala tympani are the spaces above and below, respectively. Note： The position of cochlear duct within the bony cochlea The scala vestibuli and the scala tympani, containing perilymph The scala media containing endolymph

Schematic diagram of the cochlea: The scala media is the triangle space with its acute angle attached to the modiolus.Both the scala vestibuli and the scala tympani are filled with perilymph, whereas the cochlear cduct is filled with endolymph.The spiral organ of Corti rests on the lower wall of the scala media. The scala vestibuli and the scala tympani are perilymph-containing spaces that communicate with each other at the apex of the cochlea through a small channel. 前庭阶 鼓室阶

Corti’s organ：sensor of sound vibration The tectorial membrane extends from the spiral limbus over the cells of the spiral organ of Corti.And attaches to the stereocilia of the hair cells. Between the inner pillar cells and outer pillar cells, form a triangular tunnel. On the lower wall of the scala media Tectorial membrane （盖膜） Inner (close to spiral lamina)and outer (farther from the spiral lamina) hair cells （毛细胞） Supporting cells: inner and outer phalangeal cells（指细胞） pillar cells（柱细胞）

Internal ear(NO.49) Cochlea

Vestibuli membrane Scala vestibuli Cochlear duct Scala media Basilar membrane Scala tympani

Stria vascularis （血管纹） Tectorial limbus

螺旋器（Spinal/Corti organ） Hair cell Pillar cell （柱细胞） Phalangeal cell指细胞

示教：壶腹嵴（crista ampullaris）

球囊斑（macula saculi） 椭圆囊斑（macula utriculi） 示教：位觉斑

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