ANP 1106 Lecture Notes - Lecture 7: Palpebral Fissure, Hair Follicle, Commissure

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1106
• Professor: Frank Feiner

Document Summary

Accessory structures of the eye: surface anatomy of the right eye, eyebrow, hair protects eye from sun and perspiration, eyelid, palpebrae mobile, protect eye, eyelashes, contain hair follicle receptors sense any touch -> blink. The 6 extrinsic eye muscles: originate: orbit walls/insert: outer surface of eyeball, very precisely and rapidly controlled skeletal muscles, 2-12 muscle cells/motor unit (biceps 750, 4 muscles [1,2,3,4: uo/down/left/right] not sufficient, 5 offsets medial turning when. 3 elevates eyeball: 6 offsets medial turning when. Innervation: parasympathetic: pupil size decreases (miosis, dim light/distant vision, dilator pupillae contracts. Some also flows through the vitreous humour: aqueous humour is reabsorbed into the venous blood by the scleral venous sinus. Increases with age: constriction of pupils (reaction to light, pupillary reflex: sphincter pupillae contract, convergence (coming together) of eyeballs, somatic motor fibres of cn iii move eyes medially. Homeostatic imbalances: myopia, hyperopia, presbyopia, near sightedness- distant objects blurred, focus in front of retina.