The sensory organs 广西医科大学解剖学教研室 劳明 制作 lao ming All rights reserved 1.General description 2.Visual organ

General description Concept of receptors: ( are a structure) receive the stimulation from the external or internal environment of body, and convert it into nerve impulse. Classify: Exteroceptors: in skin,the mucous membrane of the nasal and oral cavity,visual and auditory organs Enteroceptors: in the wall of the viscera, the heart,blood vessel Proprioceptors:in muscles,tendons,joint and ligaments

Sensory organs: ～ consist of receptors and accessory organs. Skin, visual organ, vestibulocochlear organ

The visual Organs (eyes) 1.Composition 1) eyeball 2) accessory organs 2.Function to receive light, color.

The wall 1.Fibrous tunic cornea sclera 2.Middle coat iris ciliary body choroids 3.Inner tunic iris part blind part (retina ) ciliary part optic part The contents Aqueous humor Lens Vitreous body The eyeball

The wall of the eyeball 1. Fibrous tunic (sinus venous sclera) Cornea ① transparent, ② non-vascular, ③ sensory nerve terminals Sclera

1) iris 2) ciliary body 3) choroid 2. Middle membrane

pupil sphincter pupillae dilator pupilae 1) The iris

2)The ciliary body the ciliary body (consist of ciliary muscle ) ciliary processes—ciliary zonule---lens ciliary muscle relax---curvature of lens↓ ciliary muscle contract---curvature of lens ↑

contains rich pigment cells and vessels 3) The choroids

3. Inner tunic ( retina) Iridial part Ciliary part Optic part optic part ciliary part iridial part (blind part)

① optic disc ( blind spot ) ② macula lutea ( yellow spot) 3.5mm to the temporal side of optic disc ③ central artery and vein of retina ( A:V=1:2) The fundus of eyeball—internal surface of post. part of eyeball

Ophthalmoscopic Examination Which side the picture show? Left or right ?

3) The structure of retina (Outer) pigment cell lamina (retinodialysis) (Inner) nervous layer ① photoreceptors (rod cells sensive to weak light) (cone cells sensive to strong light and color ) ② bipolar cell ③ ganglion cells light impulse

The contents of the eyeball Aqueous humor Lens Vitreous body Refrative media: Cornea Aqueous humor Lens Vitreous body

1.Aqueous humor form: Ciliary body Route: Post. Chamber ↓ Pupil ↓ Ant.chamber ↓ Iridocorneal angle ↓ Sinus venous sclera Function: supply nutrient, Maintain normal intraocular pressure

2. Lens 1) Biconvex,more convex for post. surface 2) Lens capsule, ciliary zonule—ciliary body 3) Near vision—increase lens convexity, far vision----decrease of lens convexity

3.Vitreous body 1)Jelly-like substance 2)supporting the retina

3.Clinically practice / Cornea--- sensitive to pain stimulating, / Aqueous humor---if circulation blocked, pressure of eyeball increase, glaucoma / Lens---if became opaque, senile cataract / Vitreous body---If supporting role weakened, retinodialysis

1. Eyelids 2. Conjunctiva 3. Lacrimal apparatus 4. Extraocular muscles 5. Fasciae The accessory organs of the eyeball

Morphology upper eyelids lower eyelids palpebral fissure Medial angle Lateral angle Medial angle Lateral angle 1. The eyelids

1) skin--thin 4) tarsus 5) Conjunctiva 3) muscles orbicularis oculi levator M Mǚller muscle 2) subcutaneous loose, no fat Structures of the eyelid

1) bulbar conjunctiva 2) palpebral conjunctiva 3) conjunctiva fornices 2. Conjunctiva

3. Lacrimal apparatus The pathway, you feel bitter in pharynx after eyedrops 1) lacrimal gland 2) lacrimal passage 1.Superior, inferior lacrimal punctum 2.Superior, inferior lacrimal ductules 3. lacrimal sac 4. nasolacrimal duct ↓ (Inferior nasal meatus )

( the name and the function of the muscles ) 4. Extraocular muscles Sup. Rectus--superomedially Inf. Rectus--inferomedially Med. Rectus--medially Lat. Rectus--laterally Sup. Oblique--inferolaterally Inf. Oblique—superolaterally Levator palpebral superior— elevate the superior eyelid

extraocular muscles Superior view

1)adipose body of orbit 2)sheath of eyeball (capsule of Tenon) 3)episcleral space 5.The connective tissue of the orbit

▲ strabismus(cross-eye) medially ▲ conjunctivitis(red eye) ▲ closed eye”—orbicularis oculi “open eye”---levator palpebrae superioris (only upper eyelid move upper) voluntary ▲ pupil diminish--- sphincter pupillae pulpil dilate----dilator puillae (unvoluntary, adjusted by light) ▲ tuyan (one of the symptons of hyperthyroidism)