1. Part Ⅳ
Sensory Organs
SHANDONG UNIVERSITY
Liu Zhiyu

2. The Sensory Organs Sensory organs include receptors accessory organs
The receptors may be divided into three kinds:
exteroceptors :receive stimuli such as touch, temperature, pain, light and sound from the external environment
interoceptors :pick up information about internal environment
proprioceptors :receive stimuli from muscles, tendons, joints and ligaments

3. chapter 1 The Visual Organ
The Visual Organ consist of
eyeball
accessory organs of eyeball

4. Section 1 Eyeball Ⅰ. Shape of eyeball anterior and posterior poles
anterior pole
Axis of eyeball :a line joining the two poles
Optic axis :a line joining the center of the pupil to the fovea centralis
Equator : an imaginary line encircling the eyeball, midway between anterior and posterior poles
posterior pole

5. Ⅱ.Structure of eyeball 1. Walls of eyeball Fibrous tunic of eyeball
Cornea
Sclera
Iris
Cilliary body
Choroid
Vascular tunic of eyeball
Pars iridica retinae
Pars ciliaris retinae
Pars optica retinae
Pars caeca retinae
Retina

6. (1) Fibrous tunic (outer layer) Cornea : anterior 1/6； Ⅱ
Wall of eyeball
(1) Fibrous tunic
(outer layer)
Cornea :
anterior 1/6；
a nonvascular, transparent
portion；
supplied richly by nerves;
because it is curved, the cornea helps focus light. Ⅱ

7. (1) Fibrous tunic Sclera: Walls of eyeball posterior 5/6,
consists of fibrous
connective tissue having
protection and surpporting
for eyeball,
posteriorly it contineus with the sheath of optic n.

8. cribriform plate of sclera
sinus venous sclerae :
lies beneath the junction of cornea and sclera, and is irregular circular canal.
cribriform plate of sclera
cornea
Sinus venous sclerae
sclera

9. iris (2) Vascular tunic (middle layer): iridocorneal angle
Wall of eyeball
(2) Vascular tunic (middle layer):
iris
lies the anterior part of the vascular tunic, and is a thin contractile membrane with a central opening, the pupil
iridocorneal angle
sphincter pupillae
dilator pupillae

10. Behind the iris，may be divided into
eyeball
Ciliary body :
Behind the iris，may be divided into
a) ciliary ring
b) ciliary processes :
60~80, producing
aqueous humor
ciliary muscle ciliary zonules
ciliary zonules

11. choroid function： Nutrition Absorb the disperse light
eyeball
choroid
Thin, highly vascular in posterior 2/3 of eye
Contains brown pigmented cells and dense capillary plexus
function：
Nutrition
Absorb the disperse light

12. (3) Internal tunic of eyeball— retina
Wall of eyeball
(3) Internal tunic of eyeball—
retina
division: ora serrata
a. Pars caeca retinae:
b. Pars optica retinae:
pars iridica retinae
pars ciliaris retinae

13. The retina consists of two layers:
Wall of eyeball
2) structure:
The retina consists of two layers:
pigment epithelial layer
nervus layer：consist of three layers of cells
Photoreceptor cells：
Cone cell
Rod cell
Rod cell
Cone cell
Pigment cell layer

14. ganglion cell, whose axons form the optic n. fibers
Wall of eyeball
bipolar cell
ganglion cell, whose axons form the optic n. fibers
Ganglion cell
Bipolar neuron
Rod cells
Cone cells
Pigment cell layer

15. Wall of eyeball
Optic disc (blind spot), located medial to posterior pole of eye, and consists of optic nerve fibers and at where there are central a.and v. of retina
Macula lutea
Lies lateral about 3.5 mm to optic disc, a shallow depression, and is yellowish in color

16. Wall of eyeball
Fovea centralis, is an aera of greatest visual acuity and is completely free of blood vessels (concentration of cone cells).
The pigment epithelial layerabsorbs light that enter the eyeball preventing backscatter (blurring of vision)

17. 2. Contents of eyeball (1) Aqueous humor 1) Chamber of eye:
lies between cornea and lens, and divided by iris into：
anterior chamber
posterior chamber

18. Helps maintain constant pressure in eyeball
Contents of eyeball
2) Aqueous humor
A clear watery fluid that fills chamber of eye，secreted by ciliary body.
Functions
Helps focus light
Helps maintain constant pressure in eyeball
Helps nourish the lens and cornea

19. Production and circulation of aqueous humor: pupil
secreted by the ciliary body
posterior chamber
anterior chamber
 iridocorneal angle
sinus venosus sclera
anterior ciliary vein
ophthalmic vein
sinus venosus sclera

20. position：lis behind the iris，anterior to the vitreous body
Contents of eyeball
(2)  Lens
position：lis behind the iris，anterior to the vitreous body
shape：
Transparent biconvex structure, covered by an elastic transparent capsule which is connected by the ciliary zonules (suspensory lig.)to the ciliary process

21. Contents of eyeball
Structure:
lens capsule
cortex of lens
lens nucleus
Its shape is 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

22. Helps maintain the shape of eyeball and supports the retina
Contents of eyeball
(3)  Vitreous body
Consists of colorless, transparent jelly-like substance in which there is a meshwork of fine fibrils, occupies the space between lens and retina
Helps maintain the shape of eyeball and supports the retina

23. (4) Refractive media:include
Contents of eyeball
(4) Refractive media:include
Cornea 、
aqueous humor 、lens
vitreous body
Bend entering light waves and focus them on the retina

24. Section2. Accessory organs
Ⅰ.  Eyelids: upper and lower ，consist of 5 layers,
①Skin
②subcutaneous adipose
tissue,
③musclar layer:
orbicularis oculi
④tarsus： formed
by dense connective
tissue (tarsal glands)
⑤ palpebral conjunctiva

25. Palpebral conjunctiva :
Accessory organs of eye
Ⅱ.Conjunctiva :
thin mucous membrane
3 parts:
Palpebral conjunctiva :
lining inner surface of eyelids;
Bulbar conjunctiva :
lining anterior part of sclera;
Conjunctival fornix
(superior and inferior):
the reflected part of the conjunctiva from the superior and inferior eyelids onto the eyeball.
Conjunctival sac

26. Ⅲ.Lacrimal apparatus 1. Lacrimal gland: 2. Lacrimal passages:
Accessory organs of eye
Ⅲ.Lacrimal apparatus
1. Lacrimal gland:
2. Lacrimal passages:  
lacrimal punctum: on each eyelid margin near medial angle
lacrimal ductules : in each lid, pass medially, join and enter lacrimal sac
Lacrimal sac : in fossa for lacrimal sac, opening into nasolacrimal duct
Nasolacrimal duct : opening into inferior nasal meatus

27. Ⅳ.Extraocular m. : 7 Rectuses: 4 superior rectus Obliquuses : 2
Accessory organs of eye
Ⅳ.Extraocular m. : 7
levator palpebrae superioris: elvates the upper eyelid.
Rectuses: 4
superior rectus
inferior rectus
medial rectus
lateral rectus
Obliquuses : 2
Superior obliquus
 Inferior obliquus

28. Accessory organs of eye
Muscle Action N. supply
levator palpebrae superioris elvates upper eyelid Ⅲ
Superior rectus turns eyeball superomedially Ⅲ
Inferior rectus turns eyeball inferomedially Ⅲ
Medial rectus turns the eyeball medially Ⅲ
Lateral retus turns the eyeball laterally Ⅵ
Superior obliquus turns eyeball inferolaterally Ⅳ
Inferior obliquus turns eyeball superolaterally Ⅲ

29. Accessory organs of eye

30. Ⅴ. Connective Tissues in the Orbit
Accessory organs of eye
Ⅴ. Connective Tissues in the Orbit
1. adipose body of orbit
lies between sheath of eyeball and the orbit acts as a protective cushion and shock sorber for the eyeball
2. orbital fasciae
a. periorbita
b. fascial sheath of eyeball
c. sheath of ocular muscles
d . orbital septum

31. Section 3. The vessels and nerves of eye
Ⅰ. Vessels of eye
1. Artery
(1)Ophthalmic a. :
Arises from the internal carotid a.
Branches:
1) central a. of retina
Enters optic nerve, passes toward the optic disk and then fans out to supply the retina

32. The vessels and nerves of eye
1) central a. of retina
branches:
superior nasal arteriole of retina
inferior nasal arteriole of retina
superior temporal arteriole of retina
inferior temporal arteriole of retina

33. The vessels and nerves of eye
2) short posterior ciliary a. :
Choroidal artery
3) long posterior ciliary a.
4) anterior ciliary a.

34. The vessels and nerves of eye
Ⅱ.Vein
(1） central v. of retina
(2） vortex vein
(3）anterior ciliary veins
(4）Ophthalmic v.
a)Superior ophthalmic v.
b) Inferior ophthalmic v

35. The vessels and nerves of eye
optic nerve:
oculomotor n.
trochlear n.
abducent n.
ophthalmic n.
facial n.

38. superior temporal arteriole of retina
superior nasal arteriole of retina
inferior temporal arteriole of retina
inferior nasal arteriole of retina

41. Sinus venosus sclerae
Ciliary Muscle
Iridocorneal angle
Dilator Pupillae
Sphincter Pupillae
Lens
Ciliary Processes
ciliary zonule

42. chapter14 视器The Visual Organ
composition   
fibrous tunic ：
vascular tunic：
retina：
cornea sclera
iris
ciliary body
choroid
walls
choroidal part: pars opticaretinae
pars ciliaris
pars iridiac
Eyeball
accessory organs of eyeball
pars caeca retinae
aqueous humor
lens
vitreous body