The Ear

1. The Ear

2. Functions of the ear • Hearing – detects vibrations in air and converts these vibrations to nerve impulses Impulses are sent to the brain and interpreted as sounds • Balance – vestibule in inner ear is responsible for balance It detects changes in body position and sends this info to brain via nerve impulses

4. Anatomy & Physiology of Ear There are three divisions of the ear • External ear – the pinna ( or auricle) gathers and passes sound vibrations through the auditory canal • Middle ear – the tympanum (or eardrum) transmits sound vibrations to in inner ear • Inner ear – also known as labrinyth receives sound vibrations and transmits messages to brain via nerve impulses

5. Middle Ear Ossicles There are three bones called ossicles • Malleus – (hammer) • Incus • Stapes – (stirrup) The ossicles transmit vibrations from the tympanic membrane to the inner ear

6. Inner Ear - Cochlea • Cochlea is known as the organ of hearing • Cochlea is a snail shaped structure filled with fluid and hair cells • These cells respond to vibrations in the fluid and produces nerve impulses • The impulses are sent to the auditory centre of the brain

7. Word components

8. Word Components

9. Ear inflammation / infections • Otitis externa • Otitis media • Otitis interna • Otitis media - more common due to the middle ear’s connection to Eustachian tube pg2

10. Procedures for ear • Examination – aural speculum allows better viewing of tympanic membrane with auriscope • Auriscope – instrument used to examine ear canal and tympanic membrane • Aural syringe – instrument used to lavage (wash out) ear that is blocked with cerumen pg2

11. Glue ear • Is the build up of fluid behind tympanic membrane • Surgical puncture…..allows drainage from middle ear • Fluid drains into Eustachian tube to nasopharynx • Grommets can be fixed to tympanic membrane to assist drainage pg3

12. Abbreviations

13. Ear Conditions / Terms

14. Ear procedures

15. THE EYE Organ of sight

16. Function of the eye • Identification of shapes and colours

17. Physiology of vision • Light enters eye through the pupil • The lens focuses light rays on the retina which is the nerve tissue of the eye • Visual receptor neurons (known as rods and cones) in retina respond to these light rays • Nerve fibres join in the optic disc • Optic disc carries nerve impulses to the brain

19. Professional branches of vision Optometry • Is the measuring of visual acuity and fitting of glasses to correct visual defects Ophthamology • Is the study of the eye and vision Opticianry • Is the practice of filling prescriptions for glasses, contact lenses and ophthalmic lenses pg1

20. Word Components

21. Word Components

22. The eyeball 2 large cavities separated by the lens of the eye • Anterior Cavity– divided into 2 parts by iris Is filled with watery fluid called aqueous humor • Posterior Cavity– lies between the lens and retina of the eye Contains a jelly like substance called the vitreous humor

23. Word components

24. Word Componets

25. Layers of the eye • Sclera – outer layer of the eyeball • Is the white of the eye covers entire eyeball except cornea • Cornea – transparent protective covering of the iris • Iris – coloured part of the eye and regulates amount of light entering eye through the pupil • Pupil – black hole in the middle of eye pg4

26. Layers of the eye • Choroid – thin brown layer that lines internal surface of sclera - is between the retinal and sclera layers • Retina – inner layer of the eye forms images to see colour shades and movements Lacrimal apparatus provides lubrication with it’s fluid and drains into the lacrimal sac and enters the nose pg4

27. Conditions and Terms

28. Conditions and Terms