10.01 mammalian eye as a sensory organ

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10.01 Mammalian Eye as a Sensory Organ. HKAL | Modern College. Session Objectives. Structure of Mammalian Eye Functions vs. Structures Accommodation Next Session. Structure of Mammalian Eye. Structure of Mammalian Eye. Functions vs. Structures. Functions vs. Structures. - PowerPoint PPT Presentation


10.01 Mammalian Eye as a Sensory Organ

10.01 Mammalian Eye as a Sensory OrganHKAL | Modern CollegeSession ObjectivesStructure of Mammalian EyeFunctions vs. StructuresAccommodationNext SessionStructure of Mammalian Eye

Structure of Mammalian Eye

Functions vs. StructuresStructureFunctionEyelidprotects the cornea from mechanical and chemical damage and the retina from bright light by reflex actionConjunctivathin transparent layer of cells protecting the cornea and continuous with the epithelium of eyelidsCorneatransparent front part of the sclerathe curved surface acts as a main structure refracting (bending) light towards the retina()protect the front part of the eyeFunctions vs. StructuresStructureFunctionCiliary muscles & Suspensory ligamentcontraction and relaxation of circular and radial muscles regulate the tension of the suspensory ligament which alters the shape of the lens Lenstransparent, elastic biconvex structureprovides fine adjustment for focusing light on to the retina and separates the aqueous and vitreous humourFunctions vs. StructuresStructureFunctionIriscircular muscle containing the pigment giving eye its colorit separates the aqueous humour region into anterior and posterior chamberscontrols the amount of light entering eyePupilopening in iris, all light enters eye through thisFunctions vs. StructuresStructureFunctionChoroidrich in blood vessels supplying nutrient and oxygen to the retinacovered with pigment cells preventing reflection of light within the eyeRetinacontains the photoreceptor cells, rods and conesOptic nervebundle of nerve fibers carrying impulses from the retina to the brain[]Blind spotpoint where the optic nerve leaves eyethere are no rods or cones here, therefore it is not light-sensitiveFovea / yellow spotmost sensitive part of retina, contains cones onlymost light rays are focused hereFunctions vs. StructuresStructureFunctionAqueous humourclear solution of saltssupply oxygen and nutrients to the conjunctiva, cornea and the lensVitreous humourclear semi-solid substancesupporting the eyeball

Functions vs. Structures

Functions vs. Structures

Functions vs. Structures

AccommodationIt is a reflex mechanism by which light rays from an object are brought to focus on the retinaAccommodationLight from Distant ObjectLight from Near Object1) circular ciliary muscle relaxed 1) circular ciliary muscle contracted 2) suspensory ligament tauts (under tension) 2) suspensory ligament slacks 3) lens pulled out thin (less convex) 3) elastic lens restores its shape (more convex) 4) light focused on retina 4) light focused on retina 5) Divergence response Both eyes are directed at the distant object for better vision 5) Convergence response Both eyes are directed at the near object for better vision. Accommodation


Wrap Up

Next SessionPupil ReflexVisionDay VisionLight VisionNight BlindnessColor BlindnessOther Eye Disorders