Transcript retina
Special Senses Week 13 OBJECTIVES • Identify the macro-structures of the eye – Diagrams – Models – Dissecting cow’s eye • Identify the microscopic structures of the retina • Identify the macro-structures of the ear • Identify the microscopic structures of the cochlea Objective 1: Structures of the Human Eye Pushing the Limits: Sight, video 3 Internal Eye Three concentric tunics (layers) of the eye: • Outer fibrous tunic • Middle vascular tunic • Inner sensory tunic - retina Retina Optic Nerve (CN II) Light Retina Human Retina Retinal ganglion cells Bipolar cell nuclei Rods & Cones Nuclei of rods & cones Outer segments of rods & cones Pigmented epithelial layer Vascular Tunic Internal Eye Three concentric tunics (layers) of the eye: • Outer fibrous tunic • Middle vascular tunic – choroid, ciliary body (ciliary muscle & process), iris • Inner sensory tunic Ciliary Body Choroid Ciliary muscle Ciliary process Suspensory ligaments Iris Pupil Lens Retina Pupil dilation & constriction Internal Eye Three concentric tunics (layers) of the eye: • Outer fibrous tunic – sclera, cornea • Middle vascular tunic – choroid, ciliary body (ciliary muscle & process), iris • Inner sensory tunic - retina Sclera Choroid Retina Lens Cornea Posterior Wall (fundus) of the Eye Retina Macula lutea Fovea centralis Optic disk (blind spot) Optic nerve The OPTIC DISC is the region were: • the optic nerve exits the eye •The central artery and vein of the retina enter and exit the eye •There are no photoreceptors, the “blind spot” Light Ophthalmoscope View Fovea centralis & Macula lutea The macula lutea is an oval region lateral to the optic disc, at it’s center lies the fovea centralis, the area of greatest cone density in the retina. Segments of the Eye Vitreous humor Anterior segment: area in front of the lens, filled with aqueous humor Posterior segment: area behind the lens, filled with vitreous humor Anterior Segment Anterior chamber: between the cornea and iris Posterior chamber: between iris and lens Canal of Schlemm Suspensory ligaments Glaucoma Fluid drainage is blocked Optic nerve fibers damaged Exterior Eye Anatomy 1? 3? 2? Orbicularis oculi muscle Sclera Cornea Conjunctiva Exterior Eye Anatomy (palpabrae) (palpabrae) Exterior Eye Anatomy Extrinsic Eye Muscles A. B. C. D. E. F. G. Lateral rectus Inferior rectus Superior rectus Inferior oblique Superior oblique Levator palpebrae superioris Medial rectus (not shown) Objective 4: Ear Anatomy 1 2 3 External Auditory Meatus Middle ear Otitis media Normal Otitis media The tympanic membrane is bulging and hyperemic ( blood), and yellow purulent fluid is seen in the middle ear space. Inner ear Vestibular & Cochlear nerves join to become the Vestibulocochlear Nerve (CN VIII) Cochlear nerve Internal Acoustic Meatus Petrous portion of Temporal bone Superior view Pharyngotympanic tube M I External Auditory Meatus (Canal) Internal Acoustic Meatus S Inner ear Tympanic membrane Middle ear Petrous portion of Temporal bone Bony Labyrinth Petrous portion of Temporal bone Membranous Labyrinth Cochlea Endolymph Cochlea histology Cochlea, cs (Endoymph) (Perilymph) (Perilymph) Cochlea S.V. S.T. Identify given structures from models and slides Hearing physiology Primary auditory cortex in temporal lobe Midbrain Medulla Vibrations Vibrations Vestibulocochlear Nerve (VIII) Balance & Equilibrium Inner Ear Vestibule – utricle & saccule Static equilibrium Responds to changes in linear movement (vertical & horizontal) Monitor head position, posture Semicircular Canals - ampulla Dynamic equilibrium Responds to changes in rotational movement Balance Objective 2: Cow Eye Dissection Identify all external and internal structures listed! lens Follow the directions given in the Lab Manual! retina Tapetum lucidum Iridescent portion (retina removed) Not present in humans Objectives 3 & 5: Experiments E HN PTXZ UZDTF D F N P T H Lab Activity: • Dissect cow’s eye • Perform visual, auditory & balance experiments and analyze On the Practical: • Identify the macro-structures of the eye from models and the cow eye • Identify the macro-structures of the ear from models • Identify the microscopic structures of the retina and cochlea