NSE 13A/B Lecture Notes - Lecture 10: Lateral Rectus Muscle, Medial Rectus Muscle, Palpebral Fissure
Document Summary
Week 10: myopia (nearsightedness, hyperopia (farsightedness, presbyopia (decrease in lens"s ability to change shape to accommodate for near vision, age 40, amblyopia (lazy eye, diplopia (double vision, anatomy and physiology. External anatomy: bony orbital cavity, upper & lower eyelids & palpebral fissure, sclera. Iris: limbus, pupil, medial and lateral canthus, conjunctiva, cornea. Irrigation to cornea and conjunctiva: lacrimal gland secretes tears, drains into nasolacrimal duct, older people. Extraocular muscles: six muscles attach the eyeball to its orbit and serve to direct the eye to points to the person"s interest. The extraocular muscles enable both straight and rotary movements. Four straight (rectus) muscles are the superior, inferior, lateral and medial rectus muscles. The two slanting (oblique), muscles are the superior and inferior oblique muscles. Internal anatomy: the outer layer: eye is composed of three concentric coats: a) the outer fibrous sclera, b) the middle vascular choroid, and c) the inner nervous retina, the sclera is a tough, protective, white covering.
