Transcript The Sensory Organs

The Sensory Organs
山东大学医学院 解剖教研室
李振华
The Sensory Organs
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Sensory organs include the receptors and
accessory organs. The receptors may be divided
into three kinds:
The exteroceptors 外感受器: receive stimuli such as
touch, temperature, pain, light and sound from the
external environment
The interoceptors 内感受器: pick up information
about internal environment
The proprioceptors 本体感受器: receive stimuli from
muscles, tendons, joints and ligaments
The Visual Organ 视器
Composition: eyeball and
accessory organs of eye
Shape of eyeball
 Has anterior and posterior
poles
 Equator 赤道: an imaginary
line encircling the eyeball,
midway between anterior
and posterior poles
 Axis of eyeball 眼轴: a line
joining the two poles
 Optic axis 视轴: a line
joining the center of the
pupil to the fovea centralis
Walls of eyeball
Cornea 角膜
Fibrous tunic of eyeball
Sclera 巩膜
Iris 虹膜
Vascular tunic of eyeball
Cilliary body 睫状
体
Choroid 脉络膜
Pars iridica retinae
Retina 视网膜
Pars caeca retinae
Pars ciliaris retinae
Pars optica retinae
Fibrous tunic of eyeball (outer)
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Cornea 角膜: anterior 1/6, a
nonvascular, transparent
portion, richly supplied by
nerves; because it is curved,
the cornea helps focus light
Sclera 巩膜 (white of eye,
opaque portion):
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posterior 5/6, consisting of
fibrous connective tissue that
forms a tough protective
covering for eyeball,
Contains sinus venosus
sclerae 巩膜静脉窦which lies
beneath the junction of cornea
and sclera
Vascular tunic of eyeball (middle)
Iris 虹膜
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Thin contractile membrane
anterior to ciliary body, with
a central opening, the
pupil 瞳孔
Contains sphincter
pupillae 瞳孔括约肌(circular
fibers) and dilator pupillae
瞳孔开大肌 (radial fibers)
Cornea and iris meet to
form the iridocorneal
angle 虹膜角膜角
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Cilliary body 睫状体
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Body a ring-shaped
thickening anterior to
equator, containing
smooth muscle fibers
called ciliary muscle 睫
状肌
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Ciliary processes 睫状突:
a series of some 60~80
projections producing
aqueous humor
Ciliary ring 睫状环
Sinus venosus sclerae
Ciliary Muscle
Iridocorneal angle
Dilator Pupillae
Sphincter Pupillae
Lens
ciliary zonule
Ciliary Processes
Ciliary ring
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Choroid 脉络膜
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Thin, highly vascular in
posterior 2/3 of eye
Contains brown
pigmented cells and
dense capillary plexus
Retina 视网膜
Pars caeca retinae视网膜盲部
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Pars iridica retinae 视网膜虹膜部
Pars ciliaris retinae 视网膜睫状体部
Pars optica retinae视网膜视部
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Lines the
choroidsComposed of two
layers
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An outer pigment cell layer
Inner neural layer (four
layers)
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The fourth layer consists photoreceptor cells
Cone cells 视锥细胞are color receptors that function best during the day
 Rod cells 视杆细胞are dark-light receptors that function best at night and
in dim light
The third layer consists of bipolar neurons 双极细胞
The second layer is formed ganglion cells 节细胞, whose axons form
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optic nerve
The first layer consists of nerve axons that collect at the optic disk
and pass through the sclera to form the optic nerve
Ganglion cells
Bipolar neurons
Rod cells
Cone cells
Pigment cell layer
Optic disc 视神经盘 (blind
spot), located medial to
posterior pole of eye, and
consists of optic nerve fibers
and central artery of retina
Macula lutea 黄斑
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Lies lateral about 3.5 mm to
optic disc, a shallow
depression, it is completely
free of blood vessels and is
yellowish in color
Fovea centralis 中央凹, aera
of greatest visual acuity
(concentration of cones), at its
center
The pigmentted layer absorbs
light that passes completely
through the anterior layer,
preventing backscatter
(blurring of vision)
Contents of eyeball
Aqueous humor 房水
Lens 晶状体
Vitreous body 玻璃体
Aqueous humor 房水
Chamber of eye 眼房－ lies
between cornea and lens,
and divided by iris into
anterior and posterior
chambers
Aqueous humor 房水
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A clear watery fluid that fills
chamber of eye
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Continuously secreted by
ciliary body into posterior
chamber
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Passes through pupil into
anterior chamber
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Then it filters though
iridocorneal angle into sinus
venosus sclerae, this sinus
drains via anterior ciliary
veins into ophthalmic veins
Production and circulation of aqueous humor
Ciliary body
Posterior chamber
Iridocorneal angle
Pupil
Sinus venosus sclera
Ophthalmic vein
Functions
• Helps focus light
• Helps maintain constant pressure in eyeball
• Helps nourish the lens and cornea
Anterior chamber
Anterior ciliary vein
Lens 晶状体
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Transparent biconvex structure, covered by an elastic transparent capsule
Located between iris and vitreous body, and suspended behind pupil by
ciliary zonule 睫状小带
Shape changed by the ciliary muscle: for near vision, the ciliary muscle
contracts and the lens rounds up, while for distant vision the lens flattens out,
so that the eye may be focused on distant objects
Vitreous body 玻璃体
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Consists of colorless,
transparent jelly-like
substance in which there is a
meshwork of fine fibrils,
occupies the vitreous
chamber, the space between
lens and retina
Helps maintain the shape of
eyeball and supports the
retina
Refractive media of eye折光装置
Bend entering light waves and
focus them on the retina
 Cornea
 Aqueous humor
 Lens
 Vitreous body
Accessory organs of eye 眼副器
Eyelids 眼睑
Conjunctiva 结膜
Lacrimal apparatus 泪器
Ocular muscles 眼球外肌
Connective tissue in the orbit
Eyelids 眼睑
（from without inwards ）
Skin, extremely thin
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Subcutaneous areola
tissue, loose and delicate
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Muscular layer: orbicularis
oculi
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Tarsus 睑板, formed by
dense connective tissue in
which the tarsal glands睑
板腺embedded
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Lined by palpebral
conjunctiva 睑结膜
Function: to protect, open,
and close eye
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Tarsus 睑板
Conjunctiva 结膜
Three parts
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Palpebral conjunctiva
睑结膜: lining inner surface
of eyelids
Bulbar conjunctiva 球结膜:
lining anterior part of sclera,
up to corneal margin
Conjuntival fornix 结膜穹
(superior and inferior): line
of reflection of bulbar and
palpebral conjunctiva
Conjunctival sac 结膜囊
Lacrimal apparatus 泪器
Lacrimal gland 泪腺
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Oval 2-cm, occupies fossa
for lacrimal gland
Ducts (6~10 in number):
empty into anterior region
of superior fornix of
conjunctiva
Secrets tears, which move
across eyeball to medial
angle,protect and moisten
eye
Lacrimal passages 泪道
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Lacrimal puncta 泪点 opening
to lacrimal ductules, one on
each eylid margin near medial
angle
Lacrimal ductules 泪小管: one
in each lid, pass medially, join
and enter lacrimal sac
Lacrimal sac 泪囊 within fossa
for lacrimal sac, opening into
nasolacrimal duct
Nasolacrimal duct 鼻泪管
courses 2 cm inferiorly and
opens into inferior nasal meatus
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Tear is produced by
lacrimal gland
Passes through superior
conjunctival fornix into
conjunctival sac
Then it is drained through
lacrimal punctum, lacrimal
ductule, lacrimal sac and
nasolacrimal duct into
inferior nasal meatus.
Ocular muscles 眼球外肌
Muscle
Action
Nerve supply
levator palpebrae
superioris
Raises upper eyelid
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Superior rectus
Turns eyeball superomedially
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Inferior rectus
Turns eyeball inferomedially
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Medial rectus
Turns eyeball medially
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Lateral retus
Turns eyeball laterally
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Superior obliquus
Turns eyeball inferolaterally
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Inferior obliquus
Turns eyeball superolaterally
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Ocular muscles 眼球外肌
Connective tissue in the orbit
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Sheath of eyeball
眼球筋膜鞘: a thin
membrane, which
surrounds the eyeball from
optic nerve to
corneoscleral junction,
permits the eyeball to
move in the orbit without
friction
Adipose body of orbit
眶脂体: lies between
sheath of eyeball and the
orbit acts as a protective
cushion and shock sorber
for the eyeball
Vessels of eye
Ophthalmic artery眼动脉
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Branch of internal artery
Branches－central artery
of retina 视网膜中央动脉
Enters optic nerve, passes
toward the optic disk and
then fans out to supply the
retina
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Four branches: superior
and inferior nasal or
temporal arteriole of
retina
Ophthalmic vein 眼静脉
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Superior ophthalmic vein
communicates with facial
vein anteriorly, exits
posteriorly via superior
orbital fissure to drain into
cavernous sinus
Inferior ophthalmic vein
lies on floor of orbit and
communicates with
pterygoid plexus, exits via
superior orbital fissure to
drain into cavernous sinus
The Vestibulocochlear Organ
山东大学医学院 解剖教研室
李振华
General features
Three parts
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External ear 外耳: collects
sound waves
Middle ear 中耳: transmits
sound waves
Internal ear 内耳: contains
the vestibulocochlear organ
concerned with equilibration
and hearing
External ear 外耳
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Auricle 耳廓
External acoustic meatus 外耳道
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Tympanic membrane 鼓膜
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Auricle 耳廓
External acoustic meatus 外耳道
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A slender canal that extends
from external acoustic pore to
tympanic membrane
Two parts
 Cartilaginous part－
lateral 1/3
 Bony part－medial 2/3
Lined by a layer of thin skin.
This S-shaped passage
medially, at first forward and
upward, then backward and,
finally forward and downward.
Tympanic membrane 鼓膜
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A thin oval membrane
Two parts
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Flaccid part 松弛部: upper
1/4
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Tense part 紧张部: lower
3/4
Umbo of tympanic membrane
鼓膜脐
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Cone of light 光锥
Middle ear 中耳
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Tympanic cavity 鼓室
Auditory tube 咽鼓管
Mastoid antrum 乳突窦and mastoid cells 乳突小房
Tympanic cavity 鼓室
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An air-containing cavity
locates within petrous portion
of temporal bone
Walls
Roof
Medial wall
lateral wall
Posterior
wall
Anterior wall
Floor
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Walls
 Roof or tegmental wall 鼓室盖壁 formed by tegmen tympani,
separates tympanic cavity from middle cranial fossa
 Floor or jugular wall 颈静脉壁separates the cavity from
superior bulb of internal jugular vein
 Anterior wall or carotid wall 颈动脉壁separates tympanic
cavity from carotid canal, superiorly lies two openings:
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Upper opening for tensor tympani muscle
Lower opening for auditory tube, which communicates with
nasopharynx
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Posterior wall or mastoid wall 乳突壁
 Aditus of mastoid antrum
 Pyramid 锥隆起
lateral wall or membranous wall 膜壁－tympanic membrane with
epitympanic recess superiorly
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Medial wall or labyrinthine wall 迷路壁
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Promontory 岬
Fenestra vestibuli 前庭窗
Fenestra cochleae 蜗窗covered by secondary tympanic membrane 第
二鼓膜
Prominence of facial canal 面神经管凸
Acute otitis media
Perforation, inflammation or
trauma
Auditory ossicles 听小骨
Consists of chain of three
bones:
 Malleus 锤骨
 Incus 砧骨
 Stapes 镫骨
 Articulate by synovial joints
 Transmit vibration of
tympanic membrane to
footplate of stapes in
fenestra vestibule.
Muscles of auditory ossicles
 Tensor tympani 鼓膜张肌
 Stapedius 镫骨肌
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Auditory tube 咽鼓管
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About 3~4 cm long, extends
from nasopharynx posteriorly,
laterally, and upward to
tympanic cavity
Two parts
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Bony part: posterolateral 1/3
Cartilaginous part: medial 2/3
Functions to equalize air
pressure on either side of
tympanic membrane
In childhood, it is shorter,
wider and more horizontal
than in adult
Mastoid antrum 乳突窦and mastoid cells 乳突小房
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Mastoid antrum乳突窦:
a small chamber between
tympanic cavity and
mastoid cells
Mastoid cells乳突小房:
contain a group of air cells
within mastoid process of
temporal bone
Internal ear 内耳
General features
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Lies within the petrous
portion of temporal bone
Key contents of internal ear
 Bony labyrinth 骨迷路
contains perilymph
 Membranous labyrinth
膜迷路is filled with
endolymph and contains
the sensory organs
Bony labyrinth 骨迷路
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Cochlea 耳蜗
Vestibule 前庭
Bony semicircular canals 骨半规管
Cochlea 耳蜗
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It somewhat resembles a
snail’s shell
Consists of
 Modiolus 蜗轴
 Cochlear spiral canal 蜗
螺旋管makes two and
one-half spinal turns
around the modiolus
 Osseous spiral lamina
骨螺旋板
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Scala vestibuli 前庭阶
Scala tympani 鼓阶
Vestibule 前庭
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Hollow bony space
Contains utricle 椭圆囊and saccule 球囊
Bony semicircular canals 骨半规管
(anterior, posterior, and lateral) posteriorly
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Semicircular duct in each
Canal at right angles to each other
Dilated ampulla in each canal，called bony ampullar 骨壶腹
Membranous labyrinth 膜迷路
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Cochlear duct 蜗管
Utricle and saccule 椭圆囊和球囊
Semicircular ducts 膜半规管
Cochlear duct 蜗管
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Contains spinal organ 螺旋
器 (of Corti), the sound
receptors lies on tympanic
wall of cochlear duct
Utricle and saccule 椭圆囊和球囊
 Contain macular utricli 椭圆囊斑and macular sacculi 球囊斑, end
organs of balance, which respond to linear acceleration and
deceleration, static of gravity
Semicircular ducts 膜半规管
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Each duct has a membranous ampullae 膜壶腹
Containing crista ampullaris 壶腹嵴, receptors of balance
that respond to rotational acceleration in three different planes
Conduction of sound
Sound waves
Cochlear nerve
Air-conduction of sound
Bony- conduction of sound
Sound waves
Skull
Bony labyrinth
Endolymph within cochlear duct
Cochlear nerve
Perilymph
Spinal organ
Internal acoustic meatus 内耳道
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Extends from internal
acoustic pore to fundus of
internal acoustic meatus
Facial, vestibulocochlear
nerves and vessles of
labyrinth pass through the
fundus of internal acoustic
meatus